How to repair an oil heater with your own hands


Oil-filled elec­tric heaters are pop­u­lar units in every­day life, char­ac­ter­ized by high dura­bil­i­ty, since their pro­duc­tion is car­ried out in an indus­tri­al envi­ron­ment using mod­ern tech­nolo­gies. How­ev­er, these elec­tri­cal appli­ances are not designed to with­stand all emer­gency sit­u­a­tions in every­day life and still fail.

The device of even the most mod­ern unit allows in some cas­es to repair oil heaters on their own.

House­hold oil-filled heat­ing appli­ances: on the left — flat, on the right — ribbed.

Con­sid­er this pop­u­lar house­hold heater from the per­spec­tive of assess­ing the pos­si­bil­i­ty of its restora­tion after a fail­ure, since it is nec­es­sary to repair an oil heater with a guar­an­tee of the safe­ty of its fur­ther oper­a­tion.

Common malfunctions of an oil heater, their signs and methods of repair

Trou­bleshoot­ing an oil-filled elec­tric heater, like repair­ing an infrared heater of any oth­er type, requires cer­tain skills and com­pli­ance with a num­ber of rules.

Impor­tant! If any of the struc­tur­al ele­ments of the oil heater fails, the oper­a­tion of the heater must be stopped until the mal­func­tion is elim­i­nat­ed.

Actu­al image of one of the mod­els of oil heaters with a list of out­door equip­ment

First of all, you should be aware that restor­ing the per­for­mance of most com­po­nents of this heater at home is impos­si­ble or requires pro­fes­sion­al knowl­edge and skills. Exper­i­ment­ing with failed elec­tri­cal com­po­nents is fraught with unpre­dictable con­se­quences (elec­tri­cal injury, ther­mal injury, fire, explo­sion), there­fore, in most cas­es, repair­ing an oil heater with your own hands, with­out pro­fes­sion­al train­ing, should only be done by replac­ing the part that has become unus­able.

In addi­tion, when repair­ing an elec­tric heater, the fol­low­ing rules must be observed:

  • the device must be unplugged;
  • the heater must be cooled to room tem­per­a­ture;
  • equip­ping the device with home­made com­po­nents is pro­hib­it­ed;
  • avoid con­tact of trans­former oil with the body, as well as with the insu­la­tion of the wiring;
  • replace­ment of a reg­u­lar net­work elec­tri­cal cable with a ground­ing con­duc­tor for a wire with­out ground­ing is pro­hib­it­ed.

Oil leak

Vio­la­tion of the tight­ness of the oil cool­er usu­al­ly occurs when it is mechan­i­cal­ly dam­aged or as a result of cor­ro­sion caused by a defect in the pro­tec­tive paint­work.

When a long-used, famil­iar oil cool­er has leaked, the nat­ur­al ques­tion aris­es, what to do, why not try to restore its tight­ness with your own hands?

How­ev­er, repair­ing an infrared heater on your own in the event of a leak is pos­si­ble only if the device is an old-style domes­tic-made unit with a flat steel radi­a­tor and a remov­able heat­ing ele­ment.

Flat oil elec­tric heaters of domes­tic pro­duc­tion with steel radi­a­tors


To make repairs, the con­trol unit is dis­con­nect­ed from the device case, under which the heat­ing ele­ment is locat­ed. Then, after dis­con­nect­ing the con­tacts, the heater is unscrewed, and the oil is drained through the mount­ing sock­et into a clean con­tain­er. The remain­ing oil is allowed to drain, after which the radi­a­tor is filled with water to pre­vent igni­tion of the oil inside it.

The wall thick­ness of such radi­a­tors is 1–1.2 mm, which allows the use of elec­tric weld­ing. The place of leak­age on the body is cleaned with a grinder with a grind­ing disc or man­u­al­ly with coarse sand­pa­per. Depend­ing on the loca­tion and size of the dam­age, a patch is cut out of steel of the appro­pri­ate thick­ness, put on the hole and scald­ed using a Kemp­pi semi-auto­mat­ic machine.

Kemp­pi machines of var­i­ous mod­els for semi-auto­mat­ic elec­tric weld­ing in the home

The weld­ing seam is cleaned and ground, after which, if nec­es­sary, it is boiled again. After degreas­ing, the repair site is paint­ed with a heat-resis­tant paint, for exam­ple, Rustins High Heat Black Pain.

Impor­tant! If the heater is paint­ed using pow­der tech­nol­o­gy, then in the course of repair work, it is nec­es­sary to strive for min­i­mal dam­age to the coat­ing — it is impos­si­ble to restore it in domes­tic con­di­tions.

Rustins High Heat Black Pain in Small Vol­ume Pack­ages

After the paint has dried, the radi­a­tor is filled to 80% with oil, and the heater is assem­bled in the reverse order.

If the oil heater clicked when heat­ed before the repair, you should not expect that the clicks will dis­ap­pear after the tight­ness is restored — the inter­faces of the body parts are deformed when the tem­per­a­ture ris­es and crack­le at the same time.

Repair of radi­a­tors of ribbed oil heaters is not advis­able, since they are made of thin sheet steel using laser weld­ing. Restor­ing the tight­ness of such tanks is tech­ni­cal­ly dif­fi­cult, in domes­tic con­di­tions does not guar­an­tee suc­cess or is com­pa­ra­ble in cost to the cost of a new heater. In addi­tion, if the heat­ing ele­ment is non-remov­able, then it is pos­si­ble to drain the oil through dam­age, but it will no longer be pos­si­ble to fill it back in.

No heating


A tech­ni­cal­ly ser­vice­able oil-filled house­hold heater makes a low crack­ling noise when plugged into the net­work. This fac­tor is not dan­ger­ous, since it is caused only by the expan­sion of the pre­fab­ri­cat­ed body of the unit, which clicks when heat­ed.

If, after turn­ing on the unit and set­ting the desired pow­er and tem­per­a­ture val­ues, the heater is silent, then the radi­a­tor does not heat up, and the mal­func­tion should be sought in the elec­tri­cal part.

First of all, visu­al­ly inspect the integri­ty of the elec­tri­cal cable. If there is no vis­i­ble dam­age, you must first dis­man­tle the racks with wheels from the bot­tom of the unit hous­ing.

Then you need to dis­con­nect the con­trol unit from the radi­a­tor, for which a stan­dard plate with the inscrip­tion Do not cov­er is pry on top of it with a screw­driv­er and removed, under which there are fas­ten­ing screws.

The loca­tion of the mount­ing screws of the con­trol unit to the body

Hav­ing unscrewed the fas­ten­ers from above, the screws are also released in the low­er part of the con­trol unit or the fix­ing springs are unfas­tened (depend­ing on the mod­el), the shell is removed from the junc­tion of the unit with the radi­a­tor, and the dis­man­tled unit is laid with the inside out.

The sequence of dis­man­tling the con­trol unit from the oil heater hous­ing

Per­form a visu­al inspec­tion of the integri­ty of the wiring and insu­la­tion, as well as the qual­i­ty of the con­tacts at the junc­tion of the wires, pay­ing atten­tion to areas with kinks and oxi­da­tion. The wire with obvi­ous inter­nal dam­age is replaced with a new one, the oxi­dized con­tacts are dis­as­sem­bled, cleaned with sand­pa­per and reassem­bled.

At the end of the visu­al inspec­tion, they begin to “diag­nose” the com­po­nents with the help of a tester — a mul­ti­me­ter, which begins with test­ing the cores of the wire sec­tion from the plug to the near­est con­nec­tion. The oper­a­tion is sim­pli­fied by the dif­fer­ent col­ors of cores in the cable of the elec­tri­cal appli­ance, which makes it easy to trace the direc­tion of the wiring.

The sound sig­nal of the tester indi­cates the integri­ty of the ringed area, the absence of a sig­nal indi­cates dam­age.

The ini­tial stage of check­ing the oil heater with a mul­ti­me­ter — the sec­tion from the plug to the heat­ing ele­ment

Replacing the tubular heater


The heat­ing ele­ment, in addi­tion to the heat­ing ele­ments, is equipped on the out­side with fus­es for cur­rent and tem­per­a­ture, the pres­ence of which must be tak­en into account when dial­ing. It is not exclud­ed the pos­si­bil­i­ty of a sit­u­a­tion where, with a work­ing heat­ing ele­ment, one of these fus­es burned out, or even both failed.

Heat­ing ele­ment fus­es: on the left — by tem­per­a­ture, on the right — by cur­rent

If test­ing nev­er­the­less revealed a fail­ure of the tubu­lar heater, then fur­ther actions depend on the method of installing the heat­ing ele­ment in the radi­a­tor. The thread­ed fas­ten­ing of the heater in the absence of rolling allows its replace­ment. In this case, the heat­ing ele­ment is unscrewed from the radi­a­tor, and instead of it, with the replace­ment of the seal­ing gas­ket, a heater with iden­ti­cal para­me­ters in terms of pow­er and shut­down tem­per­a­ture is installed.

Tubu­lar elec­tric heater of the thread­ed method of instal­la­tion in the heat­ing unit

With a non-remov­able instal­la­tion option, the heater is rolled into the radi­a­tor nest. At home, it is very dif­fi­cult to expand the old and install a new heat­ing ele­ment by per­form­ing its her­met­ic rolling, so you should think about buy­ing a new oil heater.

Temperature controller malfunction

This node is test­ed as fol­lows:

  • ring the sec­tion of the cir­cuit from the plug to the ther­mo­stat;
  • the reg­u­la­tor is set to the min­i­mum tem­per­a­ture val­ue and test­ed — the cir­cuit must be open;
  • while turn­ing on each of the heaters sep­a­rate­ly, as well as two heat­ing ele­ments simul­ta­ne­ous­ly, when the tem­per­a­ture con­troller is set to a val­ue oth­er than zero, the cir­cuit must be closed.
Inside view of the tem­per­a­ture con­troller of a 2 kW Sin­bo domes­tic oil heater

If the dial­ing of the ther­mo­stat showed its mal­func­tion, that is, the oil heater does not respond to switch­ing pow­er modes or chang­ing the tem­per­a­ture by turn­ing the fly­wheel, the device must be replaced, since diag­nos­ing its tech­ni­cal char­ac­ter­is­tics with sub­se­quent repair based on the results of test­ing in an indus­tri­al envi­ron­ment is not advis­able, and doing this in domes­tic con­di­tions is extreme­ly dif­fi­cult.

In the absence of mal­func­tions, the reg­u­la­tor is cleaned of dust, and the con­tacts are tight­ened.

Failure of a bimetallic plate


The ques­tion of whether an oil heater can explode is rel­e­vant, since the oil pres­sure in the radi­a­tor reach­es high val­ues, and the air “cush­ion” in the form of 20% of its vol­ume still has a lim­it­ed poten­tial. To pre­vent this from hap­pen­ing, there is a ther­mal relay in the design of the heater, which should turn off the heater in case of over­heat­ing.

Under nor­mal con­di­tions, this relay, which is a bimetal­lic plate, should close the elec­tri­cal cir­cuit. If the mul­ti­me­ter detects an open cir­cuit in this ther­mal fuse, then it should also be replaced with a new one with iden­ti­cal char­ac­ter­is­tics.

The con­ti­nu­ity of the oil-filled heater ther­mo­stat and the appear­ance of the ther­mo­stat

Oil heaters explode extreme­ly rarely pre­cise­ly because they have sev­er­al degrees of pro­tec­tion that dupli­cate each oth­er, and the prob­a­bil­i­ty of a simul­ta­ne­ous fail­ure of all safe­ty devices is small.

No shutdown of the heater when tipping over

Open­ing the elec­tri­cal cir­cuit when the oil heater is tilt­ed or over­turned is pro­vid­ed by a device, the prin­ci­ple of oper­a­tion of which is based on the pres­ence of a sus­pend­ed weight in its design, which, when the unit devi­ates from the ver­ti­cal, main­tains its posi­tion.

The option of equip­ping the oil heater with a cir­cuit open­ing device when the device cap­sizes — a plumb line with a met­al weight

Test­ing of this device is car­ried out by man­u­al­ly deflect­ing the heater from the ver­ti­cal. If the device does not turn off, the ele­ment must be cleaned of dust and dis­persed, or bet­ter, replaced with a new one, the instal­la­tion of which is not dif­fi­cult.

It should be not­ed that if the safe­ty switch fails, the oil heater does not explode — when heat­ing ele­ments that are not cov­ered with oil are over­heat­ed, the ther­mal pro­tec­tion of the tubu­lar heater is trig­gered, or the ther­mal relay opens the elec­tri­cal cir­cuit.


An oil cool­er is a device whose fail­ure to diag­nose on its own is quite real­is­tic, but it is bet­ter to min­i­mize the repair of this device on your own until the replace­ment of failed parts with new ones, since the oper­at­ing fea­tures (haz­ard fac­tor of using elec­tric cur­rent, high oil pres­sure and tem­per­a­ture) require pro­fes­sion­al skills and increased atten­tion to work.

To get a bet­ter idea of ​​repair­ing oil-filled IR heaters, this video will help:

The main essence of the article

  1. An oil-filled heater is a unit demand­ed by con­sumers, the design of which does not con­tain com­plex tech­ni­cal solu­tions.
  2. All mal­func­tions of the oil cool­er can be diag­nosed inde­pen­dent­ly, but most of the failed parts must be replaced with new ones.
  3. If the radi­a­tor is leak­ing, then restor­ing the tight­ness of the tank will be effec­tive only for domes­tic-made flat heaters.
  4. Exper­i­ments with the restora­tion of failed com­po­nents are dan­ger­ous, in most cas­es it is nec­es­sary to install new parts — there are enough real exam­ples when an oil heater explod­ed.
  5. Prop­er care of infrared heaters and com­pli­ance with the oper­at­ing rules is the key to many years of use of heaters with­out the need for repair.


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