Bimetal plates are the basis! Household heating appliances were marked, the electric kettle was conquered, they were located right under the button. Thanks to the bimetallic plate, the device turns off, waiting for the right moment in time, driven by steam, with a cheerful click. Oil heaters are equipped with a similar mechanism, only more complicated. More reminiscent of what was seen in the iron, mostly the old modification. The screw mechanism is driven by the thermostat knob, pressing the contact more or less against the bimetallic plate (a slightly simplified interpretation, but the approximate meaning is as follows). They say it's better to see once than to try to hear a hundred times. Meet fresh photos until the model was copied by competitors. A story about renovation oil heater with your own hands will be based on the pictures taken.
The device of the simplest oil heater
It is good to cover the oil heater with clothes to dry. The only type of devices where the owner will avoid fatal consequences. The only thing is that on the side of the accordion container there is an extension equipped with electronic filling, avoid hiding the compartment. The oil heater device includes the following elements:
Emergency shutdown sensor (thermal fuse, relay)
- A container filled with oil. Appearance - poured accordion, heated to a decent temperature, hold off touching it with your hand. When it comes to drying things, fearlessly put heat-bearing ones. The container is sealed, but there is 15% air inside. Try to put the oil heater upside down, fill it up on its side, return the load to the wheels. Heard thumps frighten mice: air bubbles burst inside. Water is not used by the heater, it will quickly evaporate, corrosion of the body will become significant, manufacturing technology would require the complete exclusion of air from the working fluid (water + oxygen = the most powerful oxidizing agent of wildlife). The coefficient of thermal expansion of the most common liquid on the planet is ten times higher than that of steel. It's not good if the tank breaks.
- The lower part of the end of the accordion contains a heating element, to which the electronics compartment clings. The oil heater is devoid of a pump and works by natural oil recirculation. The current starts from the heating element upwards, then at the opposite end of the battery the liquid descends. When working, it emits audible vibrations of the spiral under the action of AC voltage. The effect is irremovable, due to the influence magnetic field Earth. The boiling point is above 100 ºС (150-200), avoid touching the container, before changing phase state liquid is not brought due to the prohibition of the use of water: the container will break. TEN double (two spirals), will allow more flexible regulation of heating.
- Not far from the heating element is a thermal fuse. The device will not allow a fire to happen, if oil suddenly leaks out, the temperature relay breaks. The oil heater would work hard when the copper heater started to melt. Oil will leak out - through the body heat will cause the sticky thermal fuse to trip. The structure distinguishes between bimetallic (reusable) or wire (disposable). The photo shows the presence of a distinctly blackening tablet above the heating element: a thermal fuse (see the first photo of the review), or a thermal relay (determined by the design).
Steel profile that connects the electronics compartment and the heater bellows
- The relay is located at the top. We see the main difference from the iron: there is no contact with the body. It can be seen that the thermal relay simply tramples the air. An oil heater with a marked feature resembles an electric kettle, in which the bimetallic plate is often exposed to steam penetrating through a special opening in the housing. The thermal relay is an adjustment mechanism, the thermal fuse is designed to localize the event of failure of standard equipment.
- The pictures show: there are two switches, a phase, a heating element ground, one wire of a thermal relay are suitable for each. This redundancy allows the indicator lights to glow. One phase is not enough to provide the Joule-Lenz effect. The manufacturer does not know in advance which side the user will plug the plug in, whether the blue (red) wire will be zeroed, exposed to 230 volts.
The electrical part differs little from the iron, electric kettle, water heater. You can turn on both spirals of the heater at the same time, separately. In the latter case, the oil heater will reach the mode longer. There's a chance in cold room the design will work without interruption at all.
Earth's magnetic field researcher listens to the buzz of an oil heater coil
Close the air passage holes in the electronic circuit - nothing will burn, the oil heater will turn off ahead of time, the restart will not happen soon, the inflow of a fresh stream will be prevented by a drying woolen sock. The bottom of the housing of the electronic unit is cut through with supply slots. The air leaves the floor, follows, bypassing the wires, reaching the top outlet. Along the way, the bimetallic plate evaluates the moment of termination of heating.
Dismantle the oil heater
Photos of the oil heater show: the electronic unit is rolled up as a single unit with an accordion. This is wrong. The inscription "Do not cover" hides a pair of screws, the mounting bracket is held by a spring located at the bottom. It is clearly visible to the naked eye, explanations are superfluous:
- the spring is released;
- bolts are loosened.
Inside the oil heater casing, most electrical connections made with detachable terminals. If necessary, remove the switches, bimetallic relay, unscrewing the screws from the inside, opening the wires. Please note: the heating element is tightly rolled. Shows the desire of the manufacturers to not let anyone inside.
A cunning technician knows how to get acquainted
Major breakdowns of oil heaters
The heating element breaks more often, the tank flows. The oil heater is in complete disrepair. The relay will last for years. Today, Soviet irons are common, and are still operational. The mechanism cannot be repaired. You need to clean the oxidized contacts with alcohol. Repair electronic stuffing limited to element replacement predominantly. Thermal fuses are too lazy to repair: it is difficult to calculate the response temperature. Masters avoid taking responsibility. Keys, relays should be cleaned from time to time.
The main thing is the replacement of heating elements, oil, repair of holes. Those who wish to take it should know: they certainly store air in the tank. Acts as a cushion when the oil begins to expand. Protects the tank from bursting. When replacing, use transformer oil, the used one is not suitable, it will cause the heating element to become scaled up.
Synthetic varieties are incompatible with mineral ones. Those who wish can be well explained by the old-timers of automotive forums. The mechanism is cleaned of oil if there is no certainty which type is poured inside before repair.
Buck avoid soldering. Take non-tin solder - brass, copper-phosphorus, silver, use a burner. Suitable refrigerator repair equipment. It is recommended to pour water inside the tank to avoid fire. Accordingly, after work, the container must be dried. The oil is evaporated at a temperature of 90 ºС before filling. Beware of stubbornly heating the liquid - it will begin to oxidize, burn. Of course, you can freeze the oil. A thin stream is passed through a chute having negative temperature. Oil is poured into 90% of the oil heater capacity, you can measure it with any accessible way, water.
How to remove the heating element depends on the design. There is information about collapsible and non-collapsible versions. Try to select a heating element of the same power. The shell is made from copper tubes. The tank of oil heaters is steel, there is a possibility of corrosion caused by the formation of a galvanic couple.
Small holes may be bolted. Lay the thread with putty, heat-resistant sealant is used. Difficult to avoid leaks. One sealant will not do, heating-cooling cycles will cause cracks to appear. No wonder the case is made with an accordion. The structure of the metal extinguishes the lion's share of deforming loads.
Listed the main types of faults. Self repair oil heaters, when it comes to holes, is a laborious, thankless task. However, have a welding inverter handy thin sheets, localize the hole. It is important to remove, repairing a layer of rust, corroded places, to allow the seam to catch on. An oil leak repair has a chance of success.
The fall sensors went silent. Anticipate the entrance electrical circuit oil heater, at a certain roll turn off the power to the device. Checking the operation of the element is not difficult. Lay on its side, ring the contacts. The repair of the oil heater drop sensor is not justified by the risk caused by the incorrect execution of the operations. Along with the thermal fuse, we see an element that ensures the safety of operation. The information regarding the repair is presented, we hope the story is useful for novice craftsmen. The pros themselves know how to fix the problem.
Checking the operating mode switch
If the power cord is in order, then proceed to check the heater operating mode switch.
The output of the switch, to which the brown wire is connected, is common and the supply voltage is applied to it. To test the switch, you need to set it to position III, in which the common output must be connected to the other two outputs. Now it is enough to measure the resistance between the common output and the other two, it should be equal to zero. If the switch is set to position II, then the middle contact will remain connected to only one of the other two. In position I, only with not yet tested contact. In the zero position, no contact should be connected to the other. If the switch is in order, then you need to look for the cause of the heater failure elsewhere.
Checking the operation of a bimetallic thermostat
A bimetallic thermostat is installed next to the mode switch. Its principle of operation is based on the properties of different metals, to increase or decrease in size with temperature changes in different ways. If you connect two plates of different metals into one, then when the temperature changes, the resulting plastic will begin to bend. And if an electrical contact is established on such a plate, then due to the bending of the plate it will be possible to control the temperature of switching on or off electrical appliances depending on the temperature. environment. WITH useful property bimetallic plates are faced daily by each of us. For example, an electric kettle turns off a bimetallic plate heated by the steam of boiled water.
To check the health of the thermostat, just touch the multimeter probes to its terminals and turn the knob from lock to lock in any direction. In almost the entire range of rotation, the resistance of the temperature controller should be equal to zero. If this is not the case, then it is usually enough to clean with a fine sandpaper contacts that are clearly visible from the side.
If you need to remove the thermostat, for example, for replacement or repair, you must first remove the adjusting knob. It is held on the axis due to a tight fit. To remove the handle, gently pry it on both sides with flat-bladed screwdrivers. The handle with a little effort will be removed from the axis.
There are two screws under the handle. It is enough to unscrew them and the thermostat mechanism will be released.
Checking the health of the heating elements
It's time to check the heating elements connected to the switch and thermostat using a hinged six-pin connector.
As it turned out, the mikathermic heating element is composite and consists of two. One has a resistance of 60 ohms, the second 100 ohms. To check the heating element, it is enough to measure the resistance between red, blue and brown wires. The check showed the serviceability of the mikathermic heater.
Checking the vertical position sensor
The position sensor is a weight attached to the lever with a balancing spring hooked to the opposite end of the lever. When the heater is in a vertical position, the weight stretches the spring and presses against the built-in microswitch. The supply voltage is supplied to the heating elements. If the heater is tilted on its side, then the force of gravity will reduce the effect on the spring, the spring will move the lever away from the microswitch, the circuit will break, and the current will stop flowing to the heating elements.
There are two wires coming from the position sensor, white and brown. To check, it is enough to measure the resistance between them with a multimeter. When the heater is in a vertical position, the resistance of the position sensor should be zero. When tilted - infinity. The position sensor was correct.
Checking the health of the thermal fuse
It remains to check the thermal fuses connected in series, of which there were three and all of them were installed behind the micrometric heater plate. A pair of wires came from the thermal fuses white color on a six-pin connector, on the same as the wires from the mikathermic heater. A dial with a multimeter showed an open in the thermal fuse circuit. It became clear that one of the thermal fuses was faulty.
Further disassembly of the heater was required. To do this, I had to remove the second side cover and the protective grid, which is removed after being released from the screws by shifting to the side. Access to check two self-healing thermal fuses has opened.
To check the thermal fuses, with one end of the multimeter probe, you need to touch the white wire that fits the six-pin connector, and with the second probe, piercing the insulation with a needle pressed against it, touch the wire connecting the thermal fuses. The test showed the serviceability of the fuses available for testing. All elements have been checked, except for the thermal fuse behind the mikathermic heating element. So he is wrong.
I had to remove the heating element, for which it was enough to unscrew the four screws in the corners and take it aside. The next view opens.
The thermal fuse was located in a fiberglass tube and was attached to the heater body with a screw using a metal clamp.
As it turned out, there was a self-restoring thermal fuse SF192E in the tube, designed for a response temperature of 133 ° C and a load current of up to 10 A at a voltage of up to 250 V. An additional check with a multimeter confirmed the malfunction of the thermal fuse.
The thermal fuse was connected to the wires by crimping with a brass strip. Using an awl, the end of the strip on the side of the thermal fuse was bent, the thermal fuse was removed and a similar one, type G4A00, was pressed in its place, designed for a response temperature of 128 ° C and a load current of up to 10 A at a voltage of up to 250 V. The operating temperature of the installed thermal fuse is 5 degrees lower than the failed one. But taking into account the maximum heating of the heater body of only 65 ° C, such a replacement will not affect the protective functions and performance of the heater.
Before assembling the heater, all connectors were connected to each other, the multimeter probes were connected to the pins of the mains plug, and all modes of operation of the heater were checked. The resistance in the mode switch position 0 was infinite, in position I it was 156 ohms, in position II -100 ohms and in position III - 56 ohms, which indicated that the heater was in full working order.
After assembly, the heater was connected to the network and confirmed its performance. The repair of the heater is over and only traces of the tool left on the plastic plugs remind of its malfunction.
Features of heater repair
with ceramic heating elements
They brought me for repair, seemingly an ordinary fan heater, such as Timberk TFH T15DDL, due to a decrease in heating efficiency.
When the heater was connected to the mains, it was found that the fan weakly drove air, which was slightly warm. The heating mode switch and temperature control functioned normally. I had to open the heater to find the problem. The first step was to remove the dust that had accumulated in the radiator of the heating elements. The fan began to blow stronger, but the air heating remained weak.
Measuring the voltage at the terminals of the heating elements showed a value of 220 V, which indicated that the electrical circuit was in good condition. The value of the measured current consumption of the fan heater in the maximum heating mode was 1.1 A instead of the prescribed 8 A, which indicated a malfunction of the heating elements.
This is the first time I have encountered such a heating element. It turned out that in this fan heater the heating element consists of 14 ceramic-metal plates sandwiched between eight aluminum radiators. This entire package is inserted into a rectangular frame made of heat-resistant plastic and is held in place by four latches. Aluminum radiators perform several tasks at once - they hold ceramic heaters, remove heat from them and supply voltage to the ceramic-metal plates.
Attention, due to the fact that the supply voltage is supplied through aluminum radiator, touching it with the plug of the heater plugged into the mains socket is life threatening!
For better retraction heat and electrical contact the sides of the ceramic-metal plates, pressed against the radiator, are covered with electrically thermally conductive paste.
Heating metal-ceramic plates are radioelements called posistors. The principle of operation of the posistor is that its resistance depends on the temperature of its heating. The more the posistor heats up, the higher its resistance, and according to Ohm's Law, less current will flow, and as a result, the heater will generate less heat.
Due to this property, according to the developers of ceramic-metal heating elements, when the temperature reaches 300 ° C, a balance sets in, the resistance of the posistor increases to such a value that the temperature no longer increases. This ensures the safe continuation of the operation of the fan heater, even when the fan blowing air is broken and does not rotate or is clogged with dust.
Measuring the resistance of the heater sections with a multimeter showed a resistance of about 1000 ohms, instead of the proper 112 ohms. Surprisingly, it turned out that the resistance does not correspond to all metal-ceramic plates. This could happen only in case of overheating of the ceramic-metal plates, which, based on the principle of their operation, should not happen. This leads to the conclusion that the ceramic heaters were installed of inadequate quality and that they will need to be replaced in order to restore the fan heater to full operation.
To repair a fan heater, you can buy a ready-made heating block, a ceramic heater of the MZFR-J-1800W-220V type, designed for repairing fan heaters. His appearance, dimensions and the connection diagram are shown above in the photo. The MZFR-J-1800W-220V costs about $10.
Regardless of the quality, sooner or later, almost all electric heaters become poorly heated, do not turn on or do not heat at all.
Self-repair of an electric heater is not very difficult, since often this class of devices is not considered a complex device.
In everyday life, people use a wide variety of electric heaters: electric infrared fireplaces, convectors, fan heaters and a variety of oil radiators. All such devices, regardless of design features, the heating element is nichrome.
It should be noted that what simpler design heater, the longer such a device will work, and who will be easier for her husband to figure out the breakdown and fix it.
Device
For a quick and efficient repair, first of all, you need to understand how the heater works.Regardless of the type of such devices, they all have basic common elements.
The heaters are equipped with one or two key switches that can be used to select one or two heating elements that will heat, as well as lamps indicating the operation of the heating element.
The heating element may have not two contacts, but three, with two separated heating coils inside.
Immediately after the power cord with a plug, there may be a protective thermal fuse that will automatically turn off the heater after overheating, for example, if you cover the convector with a towel from above.
There may also be a tilt sensor that will work if, for example, the convector falls or overturns.
In addition to the thermal fuse, it can also be " circuit breaker"- overload current fuse, for other emergencies.
schematic diagram of heaters
Diagnosis and troubleshooting of the heater
Any diagnostics begins with disassembling the heater, but before disassembling it, it must be turned off and the plug removed from the outlet.We unscrew the screws of the case, most likely the control panel case. Having reached the connecting control panel with a thermostat, thermostat and other elements, we begin the test with a continuity of the power cord.
Next, we check the operation of all control keys and toggle switches - calling them with a tester. Then all serial circuits.
thermostat checked by the tester and it should give out zero resistance (short circuit) or close to zero on the contacts, this will indicate that the thermostat is working.
In addition to the health of the heater elements themselves, the cause of the breakdown can also be twisted in poor and unreliable contact of the conductors, over time, due to the difference in materials, they oxidize and rot, so that in this moment should also pay attention.
Then checked protective elements: position sensor and thermal fuse.
thermal fuse they call with a tester, in a good and cold state, there should be zero resistance (short circuit) on its contacts.
There can be several such thermal fuses in one housing, and as a rule, the larger the housing, the more thermal fuses it contains.
It should be noted that the thermal fuse may be working (serviceable), but due to the heavy contamination of the filters and convection holes, they can instantly work and turn off the heater.
What does it represent position sensor, so this, in most designs, is some kind of weight that, when the heater is tilted or dropped, acts on a mini switch that already opens the voltage. A serviceable position sensor, in the normal vertical position of the heater, must have zero resistance (short circuit) on its contacts.
The main deciding point will be to check the heating heating element ov. In large heaters, as a rule, there are several of them, most often there are two of them. And often the reason for insufficient heating of the room is the failure of one of the heating elements.
In most cases, the heating element cannot be repaired and is replaced with a similar one.
How to check the heating element? The resistance on its contacts can be different, depending on the specific device, but it should definitely ring. Approximate resistance values can be in the range of 20 - 100 ohms.
The main malfunctions of heaters
The heater does not turn on.
There may be several reasons. It is necessary to check the socket, plug and electrical cord. Then disassemble and make sure that there is mains voltage inside the device, it is best to use a 40W test light for this.
The voltage is checked in a serial circuit, thermal fuse, thermostat, thermal switch, heating element
Testing under voltage should be carried out carefully or use the resistance test method (with a multimeter) already without voltage.
The heater turns on but does not heat up.
The heater blows air but does not heat it, this situation clearly indicates a malfunction of the heating element, one of the sections of the spiral may be damaged, it is necessary to carefully examine the entire length of the nichrome conductor, and also ring the heating element itself with the tester, the resistance should be somewhere in the region of 70 Ohm .
In the event of a visible break or burnout of the nichrome conductor, you can try to restore it if you slightly pull the broken conductors to the center and carefully twist them with a margin to each other, then securely insert the "connection" back, but so that it does not move and does not close during operation randomly on adjacent turns of the helix.
Also, the cause of such work may be a thermal fuse or bimetallic plates of the thermostat. In a cold state, they must be closed, sometimes it becomes necessary to strip them to improve the reliability of contact. Serviceable bimetallic plates from the heat of the soldering iron should open.
The fan heater heats up but the fan does not spin (does not blow).
If the blades are in good condition and are not wedged anywhere, then the reason is most likely in the engines.
But still, first you need to make sure that voltage is supplied to the engine. Make sure that its shaft turns easily and effortlessly.
Then the engine can be checked with a multimeter, its contacts should ring and show at least some resistance.
If necessary, the motor can be disassembled and inspected inside, severe contamination is possible. Ring the windings, clean the collector assembly and inspect the reliability of the brushes. It may be necessary to lubricate the bushings of the moving part of the engine with engine oil.
If the windings burn out, the motor must be replaced.
The heater turns off (due to overheating)
There may be several reasons. For example, a large heating area and a low-power convector, as a result of constant operation, the body and internal elements overheat, including overheating protection elements that turn off the device.
In other cases, incorrect installation of the convector may be the cause. It is necessary to organize a free inflow of incoming air to the lower part of the heater and a free outflow of hot air from the upper part of the convector, nothing to cover it with and not create resistance to the heat escaping from the convector.
The oil cooler is leaking.
Self-repair in such cases is a difficult and thankless task. Adhesives and sealants are useless in this case.
To seal the holes, it is necessary to drain the oil, fill with water and use inverter welding for thin sheets. Boil the hole, after cleaning the place from paint and corrosion.
With constant oil leakage, it should be understood that the oil will still need to be topped up, since for effective work such a heater requires 90% of the oil volume of the total capacity of the oil "tank", the rest of the space should be occupied by air, it plays the role of a kind of cushion when the oil expands when heated.
No matter how high-quality the electric heater is, sooner or later it starts to heat poorly or stops working altogether. Electric heaters are not complex devices and they very rarely break after purchase during the warranty period.
I must say right away that the simpler the design of the electric heater, the less often it will break down and it will be easier to find and fix the problem.
I don't recommend on my own. repair oil radiators, because inside it is a special coolant - transformer oil. In order to disassemble it, you will first have to drain and then refill the transformer oil, and this is a very troublesome and time-consuming task. If oil just started to leak a little from the oil cooler, then I recommend soldering the place of the leak with your own hands or brewing it neatly with semi-automatic welding. In such cases, it is useless to use various sealants or glue to fix the leak.
Always unplug the heater from the socket- before starting work on disassembling or dialing the device components with a multimeter.
In order to quickly and efficiently find and fix a malfunction, you need to know the device of the electrical appliance, as well as how to check all its components for serviceability. For convenience, further I will immediately talk about the device of the electric heater, and then about checking and repairing all components in order.
How does an electric heater work?
Practically heaters are arranged similarly. Both simpler and more complex models are available. We will consider the device most difficult option. In more simple models the thermal fuse and tilt sensor may be missing in the circuit.
Let's consider a more simplified version with a single-key switch and one light bulb. Often, heaters are equipped with a two-key switch and several indicator lights, the operation scheme will be similar, with the only difference being that instead of one key there will be two, and one heating element will be, as it were, two in one case. Convection versions often have an ingress protection sensor built in, but it turns on and off the power supply in the same way as a position sensor.
Any modern electric heater consists of from a plug with a power cable, which, through a thermostat and a switch, is connected to the heating element installed in the housing - Teng. Very often, the heating element has not 2, but 3 contacts for connection. The first power wire is connected to one, and from the other from the socket, two other wires connected from a two-gang switch, which allows you to turn on either one spiral or two at once. full power.
There may be a thermal fuse in the circuit which automatically turns off the device for overheat protection. A tilt sensor can also be installed, which opens the circuit when the heater is tilted above the permissible angle. In expensive convection models, other sensors are also installed. For example, protection against ingress of objects inside the device.
In some models there may be a fuse for protection against overload currents or short circuits, which operates in emergency situations.
Step-by-step instructions for repairing an electric heater
- First thing, Before proceeding with the repair with your own hands, unplug the heater from the outlet.
- We unscrew the bolts or self-tapping screws and take out the control panel with a switch and a thermostat or thermostat.
- If the device does not work at all and the bulbs do not light up, then we check the presence of 220 volts on the cores of the cable connected to the outlet by. We replace the defective cable or plug with a new one. Just be careful- probably stopped working electric outlet, and the heater will be fully operational.
- Further on the device unplugged from the socket check the serviceability of all switch keys. In the on position, there should be a short circuit on the contacts, and in the off position, the resistance should be infinitely large (open circuit).
- At the next stage of repair check the thermostat. The multimeter should show zero (short circuit) or small resistance on the contacts.
- If the fix is still not found, then you will have to completely disassemble the electric heater with your own hands in order to get to its other components.
- Sometimes the cause of a malfunction can be quite simple.- this is a poor or missing contact at the junction of wires with terminals. Reliability is checked by visual inspection, but it is better to use a multimeter for this purpose.
- Followed by check the integrity of the heating element or heating element, as a rule, consisting of two circuits. To connect it, one common wire and two outgoing from the two-gang switch are used. To check, set the multimeter to resistance measurement mode. For example, in my personal heater, one heating element shows a resistance of 50 ohms, and the other 100 ohms. Very often, the heater stops heating at full power due to the failure of one of the heater circuits, which cannot be repaired and is replaced with a new one similar in characteristics.
- Very often the cause of the heater failure is the failure of the thermal fuse., which can be installed several in the case. If at least one breaks, all the heating elements will stop working.
The thermal fuse is checked simply (in the picture it is indicated as TP) - there must be zero resistance or short circuit between its contacts. If the device has more than one thermal fuse, then we simply remove the faulty one and connect the wires to each other, not forgetting to use heat-resistant materials for insulation. Please note that sometimes the thermal fuses may be all good, and the reason for their operation may be overheating of the convection heater due to clogged filters or air exchange holes. - The next step is to check the position sensor., consisting of a weight, which, when the device is tilted, presses the microswitch and opens the circuit. In a vertical position, there should be zero resistance or short circuit between the contacts.
- In fan heaters and some other types of electric heaters, an additional fan is installed, if it starts to make a lot of noise during operation or does not work at all, then read our
Regardless of the quality, sooner or later, almost all electric heaters become poorly heated, do not turn on or do not heat at all.
Self-repair of an electric heater is not very difficult, since often this class of devices is not considered a complex device.
In everyday life, people use a wide variety of electric heaters: electric infrared fireplaces, convectors, fan heaters and a variety of oil radiators. For all such devices, regardless of design features, nichrome serves as a heating element.
It should be noted that the simpler the design of the heater, the longer such a device will work, and who will be easier for her husband to figure out the breakdown and repair it.
Device
For a quick and efficient repair, first of all, you need to understand how the heater works.Regardless of the type of such devices, they all have basic common elements.
The heaters are equipped with one or two key switches that can be used to select one or two heating elements that will heat, as well as lamps indicating the operation of the heating element.
The heating element may have not two contacts, but three, with two separated heating coils inside.
Immediately after the power cord with a plug, there may be a protective thermal fuse that will automatically turn off the heater after overheating, for example, if you cover the convector with a towel from above.
There may also be a tilt sensor that will work if, for example, the convector falls or overturns.
In addition to the thermal fuse, there may also be a "circuit breaker" - an overload current fuse, for other emergencies.
schematic diagram of heaters
Diagnosis and troubleshooting of the heater
Any diagnostics begins with disassembling the heater, but before disassembling it, it must be turned off and the plug removed from the outlet.We unscrew the screws of the case, most likely the control panel case. Having reached the connecting control panel with a thermostat, thermostat and other elements, we begin the test with a continuity of the power cord.
Next, we check the operation of all control keys and toggle switches - calling them with a tester. Then all serial circuits.
thermostat checked by the tester and it should give out zero resistance (short circuit) or close to zero on the contacts, this will indicate that the thermostat is working.
In addition to the health of the heater elements themselves, the cause of the breakdown can also be twisted in poor and unreliable contact of the conductors, over time, due to the difference in materials, they oxidize and rot, so at this moment you should also pay attention.
Then the protective elements are checked: position sensor and thermal fuse.
thermal fuse they call with a tester, in a good and cold state, there should be zero resistance (short circuit) on its contacts.
There can be several such thermal fuses in one housing, and as a rule, the larger the housing, the more thermal fuses it contains.
It should be noted that the thermal fuse may be working (serviceable), but due to the heavy contamination of the filters and convection holes, they can instantly work and turn off the heater.
What does it represent position sensor, so this, in most designs, is some kind of weight that, when the heater is tilted or dropped, acts on a mini switch that already opens the voltage. A serviceable position sensor, in the normal vertical position of the heater, must have zero resistance (short circuit) on its contacts.
The main deciding point will be to check the heating heating element ov. In large heaters, as a rule, there are several of them, most often there are two of them. And often the reason for insufficient heating of the room is the failure of one of the heating elements.
In most cases, the heating element cannot be repaired and is replaced with a similar one.
How to check the heating element? The resistance on its contacts can be different, depending on the specific device, but it should definitely ring. Approximate resistance values can be in the range of 20 - 100 ohms.
The main malfunctions of heaters
The heater does not turn on.
There may be several reasons. It is necessary to check the socket, plug and electrical cord. Then disassemble and make sure that there is mains voltage inside the device, it is best to use a 40W test light for this.
The voltage is checked in a serial circuit, thermal fuse, thermostat, thermal switch, heating element
Testing under voltage should be carried out carefully or use the resistance test method (with a multimeter) already without voltage.
The heater turns on but does not heat up.
The heater blows air but does not heat it, this situation clearly indicates a malfunction of the heating element, one of the sections of the spiral may be damaged, it is necessary to carefully examine the entire length of the nichrome conductor, and also ring the heating element itself with the tester, the resistance should be somewhere in the region of 70 Ohm .
In the event of a visible break or burnout of the nichrome conductor, you can try to restore it if you slightly pull the broken conductors to the center and carefully twist them with a margin to each other, then securely insert the "connection" back, but so that it does not move and does not close during operation randomly on adjacent turns of the helix.
Also, the cause of such work may be a thermal fuse or bimetallic plates of the thermostat. In a cold state, they must be closed, sometimes it becomes necessary to strip them to improve the reliability of contact. Serviceable bimetallic plates from the heat of the soldering iron should open.
The fan heater heats up but the fan does not spin (does not blow).
If the blades are in good condition and are not wedged anywhere, then the reason is most likely in the engines.
But still, first you need to make sure that voltage is supplied to the engine. Make sure that its shaft turns easily and effortlessly.
Then the engine can be checked with a multimeter, its contacts should ring and show at least some resistance.
If necessary, the motor can be disassembled and inspected inside, severe contamination is possible. Ring the windings, clean the collector assembly and inspect the reliability of the brushes. It may be necessary to lubricate the bushings of the moving part of the engine with engine oil.
If the windings burn out, the motor must be replaced.
The heater turns off (due to overheating)
There may be several reasons. For example, a large heating area and a low-power convector, as a result of constant operation, the body and internal elements overheat, including overheating protection elements that turn off the device.
In other cases, incorrect installation of the convector may be the cause. It is necessary to organize a free inflow of incoming air to the lower part of the heater and a free outflow of hot air from the upper part of the convector, nothing to cover it with and not create resistance to the heat escaping from the convector.
The oil cooler is leaking.
Self-repair in such cases is a difficult and thankless task. Adhesives and sealants are useless in this case.
To seal the holes, it is necessary to drain the oil, fill with water and use inverter welding for thin sheets. Boil the hole, after cleaning the place from paint and corrosion.
With constant oil leakage, it should be understood that oil will still need to be added, since for the effective operation of such a heater, 90% of the oil volume of the total capacity of the oil "tank" is necessary, the rest of the space should be occupied by air, it plays the role of a kind of cushion when expanding the oil when heating.
