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rsburch 03-09-2006 04:37 PM

Heating going on and off constantly
 
Recently my heating has been constantly going on for about 5 seconds and then shutting off again. It repats this abut 5 or six times before it finally runs the way it should. Does anyone know what may be causing this? I have the original mechanical thermostat. I am thinking that may be the problem ut am trying to be sure before I buy a new one. Any help would be appreciated.

MgMopar 03-17-2006 07:11 PM

Hi

It is possible that it (the thermostat) is the problem. I guess without more info it will be hard to know for sure. What type of heat is it? (i.e. electric/Gas/heat-pump). Is it a forced air system? Does it use a control board or similar in the furnace or at the boiler?

It will most likely come down to process of elimination (hopefully by testing) to find out the cause of your problem. But knowing what type of system will be important to help give you a correct path to follow.

kidd 02-22-2007 11:28 PM

I agree the t-stat is probably the problem, it must have the mercury type and after a a few years it malfunctions, I have run in to this situation a few times, digital t-stats are the new era......

sfixx 02-23-2007 08:39 AM

I had my igniter go bad...and it acted kind of like that. Also, if you run the temp really high does it still cycle? It shouldn't if the mercury isn't near it's balance point. The old manual t-stats had adjustments for the mercury as well, like the on/off range.

Steve

MgMopar 02-23-2007 08:53 AM

It would still help too know what type of heat system this is:confused: Is Gas, heat pump, or electric? If it's forced air and the blower is not working correctly the burner could turn on and off like rsburch described due to the temp over limit. I have seen dirty air filters cause a furnace to run hot and after shut down the temp gets hot enough again to turn the blower on again. But with out knowing the system rsburch has makes it difficult to help:(

45frank 03-05-2007 10:34 AM

Quote:

Originally Posted by rsburch
Recently my heating has been constantly going on for about 5 seconds and then shutting off again. It repats this abut 5 or six times before it finally runs the way it should. Does anyone know what may be causing this? I have the original mechanical thermostat. I am thinking that may be the problem ut am trying to be sure before I buy a new one. Any help would be appreciated.

Sounds like a gas furnace with electronic ignition, the pilot starts but the module doesn't sense it. Most will try about 5 times then time out and have to be reset. It after the 4 or 5th time is sensing enough heat to start up. Pilot could be out of direction or the sensor could be bad.
Could be several things, need more info?


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