I have an older westinghouse gas furnace which I'm trying to get lit. The gas lights when I hold a lit match to it but turns off when I release the pilot button to turn it to on. When they turned on the gas when I moved in over the summer, the tech lit the pilot light and had it stay on. I turned it off over the summer and now can't get it back on again. I've replaced the thermocouple twice. I'll post the instructions on the furnace and my questions about it: "TO START FURNACE" "1. SET ROOM THERMOSTAT TO LOWEST SETTING" (Done) "2. MAKE SURE THAT BOTH THE MAIN GAS VALVE AND PILOT GAS VALVE HAVE BEEN CLOSED FOR AT LEAST FIVE MINUTES BEFORE PROCEEDING." (Done) "3. OPEN PILOT VALVE AND HOLD LIGHTED MATCH TO PILOT BURNER" (Done) "4. DEPRESS RED RESET BUTTON ON PILOT SAFETY SWITCH AND HOLD FOR 30 SECONDS. (A) WHEN PILOT SAFETY VALVE IS USED THE RESET BUTTON MUST BE DEPRESSED PRIOR TO LIGHTING PILOT THEN HELD FOR 30 SECONDS" (Questions here: First, I can't fine a red reset button anywhere on the furnace. The only thing I can find is a light switch on the side which says on/off. Is that what you're supposed to use as the reset switch? That is, do you turn the switch to off and then hold a match on the pilot for 30 seconds, and then turn the switch on after 30 seconds? Second question: it looks like you need three hands to do this. One to hold the pilot button down, one to hold the match and one to switch the power switch. I assume you're supposed to use a clamp to hold the pilot button down?) "5. OPEN MAIN GAS SUPPLY VALVE" (Again, this is a three handed operation? Use a clamp on the pilot button, one hand on the match and the other to open the gas valve?) "6. TURN ON ELECTRICAL POWER SOURCE" (Question: is this talking about the light switch on the side of the furnace? If so, then when is the correct time to turn it on? If this switch is being used as if it's the red reset button, then should the power be turned on between steps 4 and 5 when the gas supply is off, or after step 5 when the gas is on?) 7. SET ROOM THERMOSTAT TO DESIRED ROOM TEMPERATURE "Question: It never says to turn the pilot button to the 'on' position which I would think is important. Is this the point where you turn the pilot button to on or should you have done that sooner?" Here's what I'm doing, please let me know if you see what's wrong: 1.) Turn gas valve off 2.) Turn power switch on side of furnace to off 3.) Wait 5 minutes 4.) Twist pilot button to pilot position, press to turn pilot button on, use a clamp to hold it in place 5.) Hold lighter to thermocouple for 30 seconds 6.) Open gas valve. The gas does flow and light with a blue flame 7.) Turn power switch on side of furnace to on 8.) Release clamp pilot light button. It is at this point that the pilot goes out. Please find my included pictures to show what's going on. [url=http://postimg.org/image/vqt4468wb/][/url] [url=http://postimg.org/image/h8vww6hl7/][/url] [url=http://postimg.org/image/6tpqn9kej/][/url] [url=http://postimg.org/image/oxsr7wi2z/][/url] [url=http://postimg.org/image/r3n22eljf/][/url] Thank you!

About a 12 year old vertical installed LP furnace. Arcoaire brand, if it matters. Heats fine for just under an hour. To get it to run again, I have to pop the panel and push the little limit switch button and turn the smart control valve off and on. Then I power the unit on and it fires up and a minute later the fan kicks on and I'm heating the house again. For under an hour. In that time, the furnace isn't cycling on and off as I set the thermostat a little higher so I get continuous heat until it shuts off. Over the last year the smart control valve and inducer motor have been replaced and it was cleaned and inspected last month. Could it be just a bad limit switch?