electronic ignition fireplace won't start when lights are on

[thisisfun]

I have a Heat-N-Glo fireplace with a DSI electronic ignition module. The overhead lights are on a different circuit. When the lights are off, the fireplace will start without a problem. When the lights are on, the fireplace will not start, even though it is getting power.

The DSI module returns an error code saying it is going into a hard lockout state. I've contacted Heat-N-Glo and they have been no help. Local dealers say that these are troublesome ignition modules and that they are finicky with their grounds. I have cleaned and checked the ground connections and they seem fine.

Here are some things to add:
The two circuits do not share a common neutral.
Both neutrals are firmly screwed to the panel neutral bar.
The module is hardwired, but I unhooked it from the circuit and hooked up to a plug. The fireplace turned on when it was on the extension cord whether or not the lights were on. So it seems like the wiring from the panel to the unit is where the problem is.

Any thoughts on what is happening and how to fix it? Thanks for your input.

 

[DonL]

Why are they on a different circuit ?

That does not sound correct. Are they on the same 120V leg ?


Good Luck.

 

[Sponsor]

 

[thisisfun]

Why are the kitchen overhead lights on a different circuit? That's the way the house was wired. The kitchen lights have their own dedicated circuit. The light circuit is on the same leg as the circuit the fireplace is on.

 

[hj]

You are describing a situation where when the lights are on, the module loses its neutral connnection as if it were wired THOUGH the overhead lighting and using IT as the neutral, (in series with the light bulbs), as long as it is turned off. But when the lights are on, the "neutral" becomes the "hot' leg and power cannot flow through the ignition module.

 

[thisisfun]

Thanks for the idea hj. You are saying the circuit with the fireplace on it might be using the lighting circuit as a neutral, right? I just tested to see if there is continuity (with the power at the switches off and the breakers on) between the hot of the lighting and the hot of the fireplace and there is not. Not sure how to test if there is continuity with the power on. Any suggestions on the next step to try to test for this condition? Thanks for your suggestions.