I don't have an answer about the 2 stage regulator. I'm not a hvac guy. I had a single stage regulator on previously and had the same situation. I did check the pressure to the regulator and got 20 jn. w.c. I am getting 14in. w.c. at the inlet side of the valve, After unit starts I am getting 3...
I also installed a Big Max heater 80k btu. About ready to get rid of it. I converted it to propane with the correct kit. I am running off the house propane. Have 14 in w.c. to the regulator but after burners fire I only have 3 in w.c. on the burner side. Tried to adjust the pressure but nothing...