Originally Posted By: Tony Cherpeski This post was automatically imported from our archived forum.
A client of mine is having trouble keeping the furnace fired. It runs in two minute cycles and shuts down to do the same thing five minutes later. Any suggestions on fixing this problem?
Originally Posted By: Jay Moge This post was automatically imported from our archived forum.
defanately needs a furnace tech. but i will say that most likely it is one of 3 things. 1)out of fuel, 2) water in the fuel 3) dirty fuel filter. but i’m not a service tech so don’t take my word for it.
Originally Posted By: phinsperger This post was automatically imported from our archived forum.
Sounds like the High Limit Switch is shutting down the unit. The high limit switch is there to prevent overheating of the furnace.
Some comon problems that cause the High Limit Switch to kick in and shut every thing down are ;
Restriction in the air flow. Clogged filter, foriegn object, closed dampers, etc
Malfunctioning blower not running or running too slow
Defective or improperly set high limit switch
If the thermostat was replaced since the last heating season check it. They have a setting for a cut on and cut off temperature. These need to be several degree apart.
Originally Posted By: dandersen This post was automatically imported from our archived forum.
Check the air filter.
If it's anything other than this, call the HVAC technician.
There is a wide array of combinations that can cause a furnace to shut down. There are numerous safeties that must prove for proper operation. Any device or combination of devices can cause the furnace to cycle. It could be an induced draft pressure switch, fan controller, flame sensor, high limit safety switch, thermostat heat anticipateor, gas pressure problems, blocked flues and all the other things that people posted already.
It's the time of year to start up furnaces. All furnaces should be checked for proper operation before being placed back in service annually.
Originally Posted By: jsmith10 This post was automatically imported from our archived forum.
Definitely have a HVAC tech. service this system. It sounds like the thermocouple, as if the two from the ignighter is lighting first and then the last two it’s staging.
Of course it depends on the manufacture/type of furnace that it is.
Like Dave said , it do’s sound like there is a pressure problem also but the ONLY way to ensure this system is working properly is to have a QUALIFIED technician service it as I’ve seen a lot of owner repairs and some of them amazed me, that the family was still living.
With-out seeing the system and watching/listening it can be very hard to determine what the actual problem is.
Every system should be checked a minimum of every two years. (my personal opinion)
I'm a licensed journeyman in Idaho and have been doing HVAC for over 25 years (20 in the Air Force) and I have seen what improper maintenance & repairs can/will do.
