furnace runs when it wants to...
Posted: Tue Dec 16, 2008 9:32 pm
The furnace says it is a:
Consolidated Industries Model MBA 060 NH2R
Smart Valve is HW SV9500
I think the Electronic fan timer, which pretty much runs everything, is going out. The fan will come on, the pilot will light, and then sometimes the burners come on. Sometimes it runs perfect, other times it runs for 2 seconds, sometimes it doesn't come on at all.
I had a furnace guy out and it performed beautifully while he was there so he could not diagnose the problem. He said if he had to guess, he would replace the smart valve and accompanying burner for $485.
Tonight when the furnace shut off prematurely I heard a faint electrical buzzing. I pulled the cover off and it was the electronic fan timer, I pushed on the outside of the plastic of the electronic fan timer and the furnace came to life.
The name is deceiving, it seems to be the main control unit for the whole furnace, and also has diagnostic led's that are reporting normally of course.
The part number of that unit is Model ST9141A1002, part # 406650. I've duplicated getting the furnace to turn on after it shut off prematurely at least a half dozen times now simply by applying pressure to the outside of the plastic case. How often do these go bad? It looks like I simply cut the power, draw a diagram of the wires, take out 4 bolts, and reverse the order to install a new one. I see the ST9141A1002 406650 online for $99 to $189.
Consolidated Industries Model MBA 060 NH2R
Smart Valve is HW SV9500
I think the Electronic fan timer, which pretty much runs everything, is going out. The fan will come on, the pilot will light, and then sometimes the burners come on. Sometimes it runs perfect, other times it runs for 2 seconds, sometimes it doesn't come on at all.
I had a furnace guy out and it performed beautifully while he was there so he could not diagnose the problem. He said if he had to guess, he would replace the smart valve and accompanying burner for $485.
Tonight when the furnace shut off prematurely I heard a faint electrical buzzing. I pulled the cover off and it was the electronic fan timer, I pushed on the outside of the plastic of the electronic fan timer and the furnace came to life.
The name is deceiving, it seems to be the main control unit for the whole furnace, and also has diagnostic led's that are reporting normally of course.
The part number of that unit is Model ST9141A1002, part # 406650. I've duplicated getting the furnace to turn on after it shut off prematurely at least a half dozen times now simply by applying pressure to the outside of the plastic case. How often do these go bad? It looks like I simply cut the power, draw a diagram of the wires, take out 4 bolts, and reverse the order to install a new one. I see the ST9141A1002 406650 online for $99 to $189.