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Wall furnace doesn't come on

5.8K views 10 replies 9 participants last post by  mike3  
#1 ·
The wall furnace pilot light will stay lit but the furnace won't fully come on. It is a Cozy brand furnace which is probably about 30 years old. It has the thermostat control next to the gas valve knob. When I turn the thermostat knob up, I hear a click and the pilot light gets smaller, but the furnace will never come on.

Is this possibly the gas valve? And if so, someone told me it was easier to replace the whole furnace than just the gas valve. Is this true? Why is the gas valve so hard to replace?

Thanks for any help in advance...
 
#2 ·
before i start, i would like to assume a few things. correct me as needed. first, you are a homeowner that has no prior hvac expierience. i also assume that you will not consider my thoughts as a fix for you to preform on your furnace. i cant tell you xactly whats wrong because i am not there to look at it. i have not had the enjoyment of ever seeing a wall or floor furnace. i am under the assumption that the unit operated the gas valve on a power pile. under that thought, perhaps the powerpile is weak. i know that the safety pilot dropout in the gv is electricly operated. perhaps when both coils draw on the powerpile, [lets assume the dropout uses less current than the main] the dropout can stay open but the remaining current cant pull in the main valve. just my thoughts. pictures pleese!!!
 
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#4 ·
mr hvac41: Actually I own a small apartment complex and have been in the apartment business for about 15 or so years. I do have some HVAC experience (some classes and hands on) but I am not a professional. If powerpile refers to a thermo coupler or milli volt generator, then I did replace the thermo compler on this unit.

jultzya: I just found this site today and apoligize if my question should not be here. I have read the site rules though and not sure what you mean. And yes, I do understand that the whole unit doesn't need to be replaced if the gas valve is faulty.
 
#6 ·
jultzya said:
Unfortunately we can't give you technical advise due to the site rules.

But, there is no need to replace the whole unit IF the gas valve is found to be faulty.
Actually; if the valve/thermostat combo is anything like the Empire one, its more than twice the cost of a normal valve. If your going to spend that kind of money on a 30 year old heater, you better have it checked over thoroughly for cracks before doing so.
 
#9 ·
ebucher96 said:
Is this possibly the gas valve? And if so, someone told me it was easier to replace the whole furnace than just the gas valve. Is this true? Why is the gas valve so hard to replace?...
It seems someone has given you sound advice. It very likely is the gas valve. As far as that gas valve goes on those 30 yr old units. Yes it is best to replace the wall heater. Gas valves are expensive and in this case hard to find. So they would most likely have to retrofit it which also means more money. Do yourself a favor and replace it.
 
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