Carlin EZ Gas bizarre behavior

Hi everyone,

I recently had a Carlin EZ Gas conversion burner installed on a WGO boiler. Everything worked fine for a day, and then the system died on me. Installer is not returning calls, texts, or emails. Looking for a little guidance before I decide if this is worth having someone look at it or if I should just give it up and replace the whole system.

Behavior is as follows in standby:
1) I cut power to the system and let it sit for a couple minutes, then turn power back on.
2) Using a multimeter across B1 and B2 in L8148A aquastat, VAC starts at 0 and gradually ticks up over a few minutes, finally holding steady around 60VAC.
3) Watching the burner control, the red LED goes from totally dark and gradually brightens over the same period.

If I trigger a call for heat:
1) Aquastat relay vibrates like crazy and voltage over B1 to B2 drops to zero.
2) If I manually close the relay, voltage B1 to B2 jumps to 120VAC and the burner kicks on and fires as normal.
3) When call for heat is satisfied, the voltage between B1/B2 drops to zero and the burner dies; no post purge, etc.

Does anyone have any ideas on what might be causing this behavior? As I mentioned, it did work for the first day.

Thank you.