Heat&Glo SLR-D Cosmo IPI Pilot Won't Light

[SantasPants]

Hi. I have a Heat&Glo SLR-D Cosmo (manual) with an IPI pilot. The pilot makes a spark, but won't actually light. The fireplace was installed in 2016 and we're the first home owner in 2021 (house was empty for 5 years). The fireplace didn't light for the inspector and has never lit for us either. The fireplace is NG and horizontally vented right behind the wall it's mounted on. The outside temperature during winter when I try to use it is typically between 0-10 C (32-50 F). Some troubleshooting steps I've taken are:

• Pilot lights fine if I open the glass front for a few minutes (it won't light right away). Will continue lighting fine until it cools off
• Pilot won't light with a lighter
• Pilot lights fine if I cover the exterior exhaust with a bag
• I've hung some shredded tissue infront of the pilot, and while there is a draft with the glass open, there is no draft with the glass closed (at least not enough to move the tissue)
• Pilot won't light with a steel mixing bowl on top to block any possible draft from the top
• Pilot won't light with a shield to mostly block a draft from the bottom (see pictures), even with the mixing bowl on top too
• Spark gap looks good, about 3mm

I called a reputable company to take a look. The tech said the gas pressure was set too high, and a ground wire was loose. But sure enough the next day after it cooled off, it still won't light. The tech found the AC junction box sitting below the unit (see picture) and said it could be used to convert it to an always on pilot (which is a solution I would be happy with at this point), but to me it just looks like an AC splitter and the manual has no instructions for converting to always on. The ignition module doesn't appear to have any switch to change from IPI to continuous mode. There is no remote, just two decora wall switches for the gas and pilot.

The fact that it won't light with a lighter leads me to believe the ignitor is fine and it's more likely something to do with the pilot's gas supply, which maybe resolves when the unit is warmed up a bit by taking the front glass off? I'm also stumped why covering the exhaust with a bag makes it light instantly, but shielding the pilot doesn't seem to do anything. Any ideas and suggestions are welcome. If anyone knows of a compatible ignitor module (SRV593-592) which has a continuous pilot setting I'd be happy with that solution too.

Thanks for your help!

Pilot area without bottom shield. It's fully open on the front side:

Pilot with shield on the front side:

Two small gaps still on the back. Hard to fit a shield in without taking the whole thing apart, so I haven't done so:

Junction box the tech said can somehow be used to convert to a continuous pilot: