While testing the Propex hs2000 for a night and I ran into a problem. The red light was continuously flashing and no heat was coming out. Turns out the propane wasn't flowing, perhaps do to installing a new tank in conjunction with 4000ft of elevation gain. The fix was to simply disconnect the tank then reconnect it and do the reset procedure.

VanCafe article has some guidance if the reconnect/reset doesn't fix the problem:
https://vancafe.com/propex-heaters-fo...