LP fireplace not lighting.

[penth2o]

Hi guys. Quick question for those in the know.
I have a Propane fireplace. Worked fine. Next day won’t ignite burner. Pilot light lights but burner will not.
after messing around and taping things I noticed if I tap the back of this thing
(pic attached). with my knobs on the front of it it will light. Turn it off and won’t light. Tap a few times and it lights.
is this all one unit or is there a small piece inside that can be replaced?
the brand is Napoleon.
thanks for the help.

EDIT: Also I noticed when you turn the flame knob up or down to increase flame size, it has no affect. Stays the same flame size.

 

[The Cobbler]

that thing is the gas valve. I don't think they are serviceable .
Just an FYI, I had a buddy where is nat gas fireplace was temperamental lighting, called the store where he bought it from years ago, diagnosed "a bad ( obsolete) gas valve. this thing is scrap, go buy a new one"
Him & I got looking at it, and I found a loose connection . that was about 5 years ago & it's still working fine.

 

[billybek]

Is it a powerpile gas valve? Looks a lot like the one in my fireplace.
Try jumpering the t'stat wires at the gas valve and see if it lights.
Next thing you can try is replacing the powerpile. They do last a long time but not forever!
As mentioned above, it could be a bad connection.

 

[FredWanaker]

call the service guy or replace. If you need to ask the Internet how to service a gas valve... need I say more.

 

[nadogail]

To have a fire you need three things; they are fuel, oxygen, and a source of ignition.
If you have a steady pilot flame, one can assume you have both fuel, oxygen, and the pilot flame should light the main flame after the Gas Valve opens.

Your Gas Valve opening may be dependent on sensing that the Pilot flame is burning, if you have a Thermocouple covered by the Pilot Flame; I would suspect the Thermocouple. A good Gas Valve looks for an input signal from the Thermocouple before opening, without thst input the Gas Valve should not open. This is a safety feature. It has been more than 30 years since I have seen a problem like this, your local Hardware Store may no longer stock Thermocouples, Take your old one with you when you look for a replacement, they vary in length.

Turning knobs and controls on a Gas Valve that is not open is equivalent to pressing the accelerator on a car without the engine running.

Based on the OP's post the repair should be done by an experienced technician.

 

[gmcgeo]

if you are tapping it, then you here a click and it opens, this means the gas valve is sticking. "magnet not dropping? this is common on older fireplaces. This happens when the gas valve is starting to fail inside. time to replace it. you may notice it start working for a while but soon it will just not open anymore.

 

[BillK]

Your Gas Valve opening may be dependent on sensing that the Pilot flame is burning, if you have a Thermocouple covered by the Pilot Flame; I would suspect the Thermocouple. A good Gas Valve looks for an input signal from the Thermocouple

If the Thermocouple was bad the pilot would go out. Since the pilot is still working the thermocouple is fine. If its not a loose connection where the wires attach to the gas valve then it really seems like the valve is done with.

 

[gmcgeo]

EDIT: Also I noticed when you turn the flame knob up or down to increase flame size, it has no affect. Stays the same flame size.

you will not see a difference in the flame height, however it is changing the BTU out put.

 

[4x4Pete]

That gas valve has both a thermocouple and a thermopile. The thermocouple is for the pilot only. The thermopile is for the main valve operation amd to provide enough power to have a thermostat and safety controls in the circuit. Sounds like there is a bad connection in the wiring. I'd try to clean/tighten all wiring connections since there's usually only 450mv to start with. There may be a resistance that is providing power but not enough to open the main valve. It helps open the valve when you give it a tap. Or the thermopile is failing
Pool heaters are the worst for this same problem. A lot of them run with just a thermopile doing everything Stupid design since there's a line votage pump nearby that has to be running for the heater to operate.

 

[1jeepfan]

I have personal experience with these fireplaces, but am not a technician. So…
Yours probably has a thermocouple, which senses a flame and keeps gas flowing to the pilot light only. That does not sound like your problem because you said the pilot is working.
There is also a thermopile, that senses a flame(pilot light), and allows gas to the burner, which is lit by the pilot. This could be your problem. You can try cleaning it with fine sand paper or emery cloth. It can be tested with a good circuit tester. A new Thermopile will run you about $25.
It could be the gas valve(the component in your pic). they run about $150-300 depending on brand and model. Also, that flame adjustment knob on the valve controller usually adjusts the size of the pilot flame only.

Good luck.

 

[gmcgeo]

could be what 4x4pete said, easiest and cheapest way is to replace thermopile. however i suspect it is the valve.

and the thermopile should be reading 800+ mv when pilot is lit. then burner comes on and runs at 500mv, anything below 500 the thermopile is bad

 

[penth2o]

Welp, turns out the thermopile just needed the soot sanded off it. Thank you for all your help and suggestions minus the reply from Fred Wanaker. If I followed that advise I’d be hundreds into a service call to blow soot off.
That’s the purpose of forums to BS and shout out solutions from our similar experiences and problems.
If not then we would just be all showing pictures our birdhouses we made.
thanks again folks.

 

[gmcgeo]

that's great that's all it was!! check to make sure your pilot is nice and blue. if its sooting on the thermopile the pilot may need cleaned.

 

[penth2o]

Yes. Thanks. I got it all. Tightened connections and checked resistance on what I could.

 

[fitter30]

350 mv powerpile is a 1/3 of a volt since pilot stays on jump out thermostat at the valve.

 

[trainer]

I had similar problems a while ago with my fireplace.

Mine has an interrupted thermocouple that needs voltage from the thermopile plus a flame to keep the pilot lit. The pilot light started going out occasionally and became progressively worse. Thermopile tested ok so I replaced the thermocouple and cleaned the thermopile.

That didn't fix the problem, so I put in a new thermopile. It works perfectly now. Looks like the thermopile was going out intermittently.

Total was under $50 in parts from the corner hardware store. A service call would have started at $250

 

[nadogail]

congratulations on your sucess.