Stadt J90 Heater electrical buring smell when unit fires up smell goes away after 5 - 10min for a day or 2 then comes back. Check but no signs of fire or smoke or burnt area. Unit is old but works well other than the smell

Check for loose connection or broken wire. Pull on wires you’ve connected.

Broken heater core. Keep an eye on your antifreeze level

1 if you smell gas do not operate this unit until you find this leak or sourse of leak. one thing you can do is get a spray bottle and mix up a very soapy mixture of water and soap. before you trun anything on spray any connections , joints , or threaded piping leading to the heater, If you see bubbles forming any where on any joint you have a leak. keep at this until you are satisified there are no leaks at the joints. Next check all connections that are inside the furnas using a wrench you do not need to over tighten any thing but with gentle force look for a lose fitting.,, Then turn the heater on and spray all the joints again to try to find a leak. and check the bruners and see that they are all fired up. if you don't find any thing you might have to call a tech.
Just a note on new units like your some purge the fire box before they fire off . so when you smell gass is it all the while the unit is running? or does it go away? you might be smelling the purge in which case you may need to add a stack to the vent on the unit . Let me know what you find

o my friend i hawe a same problem in macedonia it hawe a mystake in elektronk part in airconditioner...and maybe is dthe outside part of split termik is not ok maybe ...

A burning smell could indicate an electrical problem (something overheating) or, if the unit has electric strip heaters that have not been energized for a long time, the buring smell could be the dust burning off of the heaters.

First of all keep this in mind.
You will need to locate the wires that got hot. If you can't or if your not sure, I suggest that you call a service company. If they ok the unit and it catches on fire after wards, their insurances will cover you unit and or home if god forbid it burns. This is to be on the safe side.
Now, this is where I would look. Your element should be on it's on circuit. There should be a disconnect within reach of the air handler. Some are fused and some are not. The wires that got hot enough for you to smell them should show signs of being hot like the plastic will be melted around the wire. You said that the heater was running. Was this the first time you have used it this year? If so, are you sure it was not the dust burning off the elements? They will smell like something burning when you first turn them on each year. Although if your sure you smelled wires getting hot, please continue looking for just that. Keep in mind that the elements have 220 volts coming to them. It comes into the unit and go to a switch or relay. From there the power goes to the elements and then to a neutral. These are the wires you will need to pay the most attention to. Good luck.

Turn off any electricity to your heater, if after a while the gas smell goes away then you might have a low voltage problem. Otherwise the gas valve inside the unit may be defective. If you smell gas don't fool around with safety. Pipefitters and Gas Suppliers may be of little help, get a trained HVAC Tech. Good Luck

I would check the defrost thermostat usually a button type switch with 2 wires on it mounted to the freezer coil. Size depends on type ; 1 type is about quarter size, 1 is about dime size, and electronic sensor (not had one burn out but the board could smell like your description but I believe these are not in the freezer section).

I have had these cook out and smell up the freezer section before. And if they go out guess what it wont defrost either. If your fan motor goes out it might smell and wont cool all over but the frost should be minimal.


Also a bad defrost heater could make a smelly situation it is usually a black rod or aluminum colored and the rubber ends can burn and make a smell.
If you find its the heater, I would replace the defrost thermostat as well. Its suppose to cut off the heater before it gets too hot.

If this helps you find your problem please rate me as high as possible if not please post back with more information as to what you did find. Thanks for using fix ya and good luck.

Mhenn, It is my guess that the 'electrical burning' smell is from your heating system. Since there is no smoke and the walls are not warm.... then there is no real problem. The smell maybe just dust has collected in the duct work that is burning off the central heating systems electrical heat strips. If you have electrical heat strips then that may be the problem. If you have a central gas heat system, it may be the same type problem. Hope this helps you. Henry

If you need further help, I’m available over the phone at https://www.6ya.com/expert/henry_239f63a136de60f0

stadt ducted heater wont ignite