Dayton LP unit heater burner problem?
I just installed a new (bought from a liquidator not sure how long its been sitting around) Dayton 200,000 BTU LP unit heater w/standing pilot. The unit does not seem to light well each time and I dont see much of any pattern.
It has a 8" B-vent that comes out of the heater about 12" into a Tee and straight up through the roof. It sticks up through the roof about 24" on the high side (of the roof). Total length of vent is about 5'.
Gas pressure was set by propane company @ 11 psi where it enters the building, when the unit is running it shows about 10.5 @ the inlet of the gas valve. burner side of gas valve shows about 9.5-9.75 with unit running. It calls for 10. Propane guy tried to adjust pressure up @ gas valve but it would not change no matter how much you moved adj screw.
This problem has been there since the first lighting.
Come in first thing about 55 degrees inside and turn up stat.
Now when it lights some times the flame will pop back, some times worse then others. This has 8 burner tubes and most of the time 4-6 of those tubes will have the flame burning above the tube slightly and noisy ( no nice blue tips like when there burning good).
Some times only 3 tubes may act up, some times 1 tube, but most of the time some of the burners act funny. I Let it run a couple of mins, then turn down stat and let it shut off it may start fine with no problem. Yesterday unit was off and cold, turned up heat and flame popped back pretty good, and maybe 6 - 7 burners were noisy and flame was lifting per say. I shut it down after maybe 2 mins and restarted and no pop back and all burners were fine. Now Im thinking the flame pop back may be causing the burner problem.
One odd thing I did noticed was that when unit is running pilot gets big,yellow and lazy (floaty), once it shuts off it goes back to normal size with nice blue flame.
kind of made me think some problem with gas valve since we cant seem to adjust it.
Owners manual lists
to much primary air, I checked that(I re-adjusted and I ended up right back where it started as per book)
or orifice to small (did not check that) Any ideas where to start with this? there was nothing else during install that looked out of the ordinary.
Thanks for your time
hope this all makes sense