Fireplaces, Heating Stoves, Flues and Chimneys - Gas fireplace - pilot lights but main burner won't come on

Hello everyone,

I just moved into a house that has a gas Pacific Energy fireplace, model unknown. The pilot light comes on and burns strong, but the main burner doesn't.

I've done some reading around the 'net and here's what I've tried:

1. I took out the logs and vacuumed the insides thoroughly.
2. I've measured the voltage between TP/TH and and TP terminals on the gas flow knob and voltage appears to be around 600mV (if I measured it properly).
3. If I connect TP/TH and TH terminals directly the main burner comes on. As soon as I remove the connection the flame dies.

There's a wall switch, it appears to work, because manual fan control works while switch is on, and doesn't if the switch is off.

So the gas is on, the pilot appears to provide enough heat to power the main burner, what else could be going on here?

Thanks in advance, I'd appreciate any advice before I go and spend money on a service guy.

nevermind. :o.....................................................................

nevermind. :o.....................................................................


I'm sorry?...............

I have similar problem with my gas only fireplace.

It is different brand though. The pilot works fine. But the wall switch
can not turn on the fire. If I use a wire to directly connect two terminals
on the gas valve, the fire comes on.

I suspect there is a protecting mechanism along the circuit with the
wall switch to prevent the fireplace from being burnt too hot. The device
is mal-functioning.

Please post if you find the cause.

Thanks,

I'm sorry?...............

I posted something but I didn't read your post well enough. I couldn't delete it so I just put "nevermind" to take up space. Sorry for any confusion.

Possible faulty pressure switch,pressure regulator faulty,

I double checked the circuit diagram again (a plate inside
the fireplace). It does not have any protecting device.

I further checked the voltage from the thermopile and it
reads 0.48 v. But when I turned the wall switch on it only
reads 0.19 v, which is barely enough to turn on the
millivolt valve (it needs 0.25 v). Shorting the terminals on
the valve works since it makes less voltage loss in the circuit.

I think the thermopile is a bit too old. That is why it works
intermitantly. I serached on net and found some others
changed the thermopile and fixed the problems.

I will give it a try and see what happens. :D

It is probably your wall switch that is faulty. Try jumpering the wires at the wall switch. Those switches are not designed to operate properly with such low voltages. The contacts build up resistance over time. It could also be too long of a run to the switch. How far away is the switch?

Thanks for the reply.

For the wall switch, I actually took it apart last year and
did not find any problem with my multi-meter. The switch
is next to the fireplace.

I've checked the voltage across the wall switch circuit
when turned on. It has voltage drop of 0.034 v with current
of 0.060 A. This translate to around 0.5 Ohm. It is probably
reasonable with all the wires.

The problem is that when the wall switch is on, the voltage
across the thermopile drops to below 0.019 v and unless
the valve draws too much current, the thermopile should
maintain 0.025 v or more.


It is probably your wall switch that is faulty. Try jumpering the wires at the wall switch. Those switches are not designed to operate properly with such low voltages. The contacts build up resistance over time. It could also be too long of a run to the switch. How far away is the switch?

If the main burner comes on when you connect the TH/TP and TH terminals and it does not come on with the switch, then the problem is with the switch and/or switch wiring.

Take the wires off of the switch and touch them together. If the fireplace comes on, then you know it is the switch, replace switch. If it does not come on, the problem is with the wires, run new wires or install battery operated remote.

That is a good idea.

It has been working these couples days when weather
is a bit warm. But I know it will happen again and I will
try jumping the switch.

thanks

If the main burner comes on when you connect the TH/TP and TH terminals and it does not come on with the switch, then the problem is with the switch and/or switch wiring.

Take the wires off of the switch and touch them together. If the fireplace comes on, then you know it is the switch, replace switch. If it does not come on, the problem is with the wires, run new wires or install battery operated remote.