Heat & Glo Cosmo-SXT-IPI / Cosmo-GXT-IPI won't light anymore

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.


New Member
Jan 18, 2022
Hey there. Have had this model for about 11 years now with no problems. Have used it almost every day for the last month or so, and suddenly it no longer lights at all. No spark when I flip the wall switch, no nothing. More details:

1. Fresh D-batteries do not seem to help. Have used these in a power outage once and they worked fine.
2. Tested voltage output by 3VAC transformer and voltage is solid.
3. Eliminated wall switch as a variable by manually touching wires together.
4. GFCI in bathroom right behind the fireplace was tripped, which I thought was suspicious at first, but doesn't seem related now due to previous items in this light. Could have tripped in relation to this problem or could have tripped months ago... we never use it.

I am thinking the problem is downstream from the transformer somewhere. Either the board or the ignition module itself.

Thoughts? Many thanks in advance...
Have you tried the batteries with the 3V transformer unplugged from the receptacle?
I believe it'll prove the module is not reacting to the voltage & has failed.
Worst case, take the module to your local HnG dealer's Service Dept.
& have them try it in a test board.
Yep, tried that to no avail as well. Does not work with power adaptor unplugged and batteries inserted. The thing that really sucks about this is I can barely reach any of the parts because of the custom steel fireplace surround. I can disassemble if I need to but wanted to exhaust all possibilities before that.
@DAKSY Looks like the fireplace service guys are booked a couple of months out so going to try and do this myself. Do you reckon it's the controller or the ignition assembly or something else? Just not sure what normally fails on these things. Thanks.
Ok, got the green module out. Seems like it tests fine, as far as I can tell. If I leave it powered by the 3VAC transformer, then unplug the orange and white wires which go to the igniter, and then hold a multimeter to the terminals, I see spiking DC voltage from 4 down to 0, which seems like what is supposed to happen when you flip the wall switch. I *think* that only leaves the ignitor assembly, which I guess I will just order for $50 and see what happens. This is going to be invasive to replace though.
@DAKSY Welp, you were right! Even though the green module seemed to test correctly on the multimeter, popping a new one in fixed the problem immediately. Don't need to disassemble the fireplace now! Also saved about $400 and two months for a service visit. Thanks man!
  • Like
Reactions: DAKSY