Gas furnace pilot problem

[rbj]

I have a problem with my pilot on my Williams model 650DVX LP gas furnace. It is a stand up type, sealed combustion, 60,000 btu LP gas heater with a built in fan. The problem I am having is trying to keep the pilot lighted. I turn on the unit, light the pilot, turn up the thermostat, and the burner lights. I then let it run until the thermostat shuts off. As the burner shuts down, the pilot flame grows smaller and smaller (takes maybe 7 secs) and then shuts off completely. I have replaced the thermocouple (Two times), and replaced the heat exchanger(this was per the manufacturer�s recommendation. I am running out of parts to replace. Could the problem be a defective gas valve for the thermocouple? Any help would be appreciated. I ran some voltage tests on the thermocouple, here are the results: Pilot on- 8.8 Burner on(no fan)-goes up to 11.5 Fan on-8.8-6.7 Burner off-drops down to 2.4-flame goes out Thanks Mike Velardi

[Michael VelardiParticipant]

Mike, Have you considered there might be some restriction in the pilot line? Maybe worth removing the line and blowing it out to be sure no rust or something is preventing adequate flow of LP. Let us know what you find out.

[Michael VelardiParticipant]

Look at the possibility that some feature of your home / landscaping is causing wind swirls of some kind and screwing with the pressure balances of the combustion air for this heater. I have seen some wierd things like this. common sense applys.Double check the gas pressure. LP should use 2-stage regulation. 1-regulator at the tank, a second near the heater. Typically, a LP appliance should be run right at the top of the reccomended pressure range (example, if the mfgr says 11-14 lbs pressure, run it at 14 lbs.)Good luck.: ?I have a problem with my pilot on my Williams model 650DVX LP gas furnace. It is a stand up : type, sealed combustion, 60,000 btu LP gas heater with a built in fan. : The problem I am having is trying to keep the pilot lighted. I turn on the unit, light the pilot, turn : up the thermostat, and the burner lights. I then let it run until the thermostat shuts off. As the : burner shuts down, the pilot flame grows smaller and smaller (takes maybe 7 secs) and then shuts : off completely. : I have replaced the thermocouple (Two times), and replaced the heat exchanger(this was per the : manufacturer�s recommendation. I am running out of parts to replace. Could the problem be a : defective gas valve for the thermocouple? Any help would be appreciated. : I ran some voltage tests on the thermocouple, here are the results: : Pilot on- 8.8 : Burner on(no fan)-goes up to 11.5 : Fan on-8.8-6.7 : Burner off-drops down to 2.4-flame goes out : Thanks : Mike Velardi

[Michael VelardiParticipant]

The pilot flame may not be centered on thermocouple. When the velocity of air moving up the chimmney changes [drops off on burner shutoff] the pilot flame doesnt fully heat thermocouple. The valve shuts off slowly because there is heat on thermocouple, just not enough. Clean pilot jet, adjust flame so that thermocouple is centered in flame. Also check chimmney stack for proper installation, wind and temp effect air flow inside furnace.: I have a problem with my pilot on my Williams model 650DVX LP gas furnace. It is a stand up : type, sealed combustion, 60,000 btu LP gas heater with a built in fan. : The problem I am having is trying to keep the pilot lighted. I turn on the unit, light the pilot, turn : up the thermostat, and the burner lights. I then let it run until the thermostat shuts off. As the : burner shuts down, the pilot flame grows smaller and smaller (takes maybe 7 secs) and then shuts : off completely. : I have replaced the thermocouple (Two times), and replaced the heat exchanger(this was per the : manufacturer�s recommendation. I am running out of parts to replace. Could the problem be a : defective gas valve for the thermocouple? Any help would be appreciated. : I ran some voltage tests on the thermocouple, here are the results: : Pilot on- 8.8 : Burner on(no fan)-goes up to 11.5 : Fan on-8.8-6.7 : Burner off-drops down to 2.4-flame goes out : Thanks : Mike Velardi

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