Have Empire Model DV-25-2SG propane direct vent furnace. Pilot lights and stays lit when knob turned to ON. However, when raise thermostat temp from Off the main burner appears to light for an instant and then goes out as does the pilot. Help. It's colld up here in the mountains. This unit is only several years old with few hours of use.
I changed the thermocouple but the problem persists.

Replace the thermocouple that should do it, they get weak. Do you use it a lot?

I believe your unit has a milivolt/pilot generator as well as a thermocouple. If the pilot generator is present and is not supplying milivoltage for the system to operate then it will shut down.

Usually a milivolt Generator has two wires.

Here is the manual for your furnace. SEE page 15 for your thermopile/pilot generator/milivolt generator. These items are called different things by different companys/manufactures.

Your manual save a copy for future reference.

http://www.obata.com/clients/Empire/pdf2008/manuals/DV-2535-2SG.pdf

Many thanks for your response. I replaced the thermocouple but the problem persists.
I could see nothing in the manual except the pilot thermocouple I replaced.
What do you recommend I do next?
Is there an adjustment for the voltage if I measure it for the values indicated in
the manual.
Again, your help is much appreciated.

Replace the thermocouple that should do it, they get weak. do you use it alot?

I replaced the thermocouple but the problem persists.\
What do You suggest I do next?

Try taking the thermostat off the wall and jumping the two wires at stat together, let me know if funace burner comes on and stays on. If you have a millivolt system, you need a special millivolt thermostat or the thermostat can rob enough power causing your problem. Can you post a clear picture of your gas valve and wires connections on gas vavle, this will help us trouble shoot the system.

Hi,
I did as you suggested. When I crosses the stat wires the result was the same as before. The main burner flared up for a moment and then it and the pilot went out.
The thermostat came with the unit so should be correct. It did, in fact, work OK last season.
Believe I mentioned I have replaced the thermocouple.
I have pictures as you requested but don't know if I can figure out how to send them as an attachment or whatever.
Clark

try taking the thermostat off the wall and jumping the two wires at stat together, let me know if funace burner comes on and stays on. If you have a millivolt system, you need a special millivolt thermostat or the thermostat can rob enough power causing your problem. Can you post a clear picture of your gas valve and wires connections on gas vavle, this will help us trouble shoot the system.

Hi,
I did as you suggested. When I crosses the stat wires the result was the same as before. The main burner flared up for a moment and then it and the pilot went out.
The thermostat came with the unit so should be correct. It did, in fact, work OK last season.
Believe I mentioned I have replaced the thermocouple.
I have pictures as you requested but don't know if I can figure out how to send them as an attachment or whatever.
Clark
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Can you post a pic of the thermopile/pilot area?

The silver braided wire looks like the wire that is on a thermopile generator. I will look at the manual also. SEE page 11 in the instructions. It says you have a thermopile device in your unit. If it is weak it will not generate enough curent to activate and hold the gas valve on.

I'm seeing the red and white for the thermopile, but can't figure out where your thermostat wires are hooked up. Seems like the black wire on the bottom in last pic should be hooked to stat as well as another wire. Try jumping between top and bottom terminals on gas valve, it that doesn't work, try jumping between middle and bottom and let me know if it stays on then.(this is only temporary for the purpose of trouble shooting).

im seeing the red and white for the thermopile, but can't figure out where your thermostat wires are hooked up. seems like the black wire on the bottom in last pic should be hooked to stat as well as another wire. Try jumping bewteen top and bottom terminals on gas valve, it that doesnt work, try jumping between middle and bottom and let me know if it stays on then.(this is only temporary for the purpose of trouble shooting).
When I crossed the terminals as you said, the main burner did not even "attempt" to light as it did when I crossed the stat wires. The pilot just went out with no response from the main burner. Sorry but the photo did not show the stat wires. They connect to the 2 outside terminals

Did you replace the THERMOPILE and I do not mean the thermocouple you mentioned before? Did you dowmload the manual I posted for your unit?
Did you check the wiring of your unit as shown in the manual?

You might have a short in your thermostat wiring.

I have the same problem. Did you guys ever come up with a solution??

I had similar problems, with the exception that the pilot stayed on, and did not respond to the thermostat. I thought that it might be the thermopile, but ended up being the thermostat. When I crossed the wires as the thermostat, the heater turned on. I swapped out the thermostat, and voilà... Thanks for the start guys