Needing help with my H82 heater

[Smallblockfuelie]

Ive been using it for a few years now without issue, but the last week it’s delaying me fits. I can go through the startup procedure and get it to light off and make heat, but after cycles “off” and isn’t making heat it won’t go back to the heat cycle and ends with the dreaded alarm/safety release. Ive gone through the trouble shooting section of the TM I have, but it doesn't cover the issue I’m having.

I just sat and watched the pressure gauge as it was operating. It comes up to around 120 psi while it’s making heat and holds steady until it cycles off the heat cycle. The pressure drops down to normal and then jumps back up to 120 when the heat cycle starts up again. It runs for about 10 seconds and then I get the safety release.

I’ve got it inside my shop with the exhaust going through the wall. It’s too close for me to see if there is a flame through the inspection window. ( I don’t have an inspection mirror, but I’ll get one on my next trip into town. ). If I leave it on vent for 5 minutes and prime it with the S7 toggle switch it will light off and run again like I described above.

I’ve cleaned the fuel bowl, there was little to no sediment in it. I’ve gone over all the visible fuel lines, no leaks any where. Any pointers would be greatly appreciated. Thanks.

 

[155mm]

Over pressure, try running 80-90 psi

also pull front cover, make sure the flame sensor sees the burn chamber

 

[Smallblockfuelie]

Over pressure, try running 80-90 psi

also pull front cover, make sure the flame sensor sees the burn chamber

thank you. 120 looks like the correct pressure for my elevation and it has been running for years at that setting. Should I still adjust it down to 80-90?

 

[155mm]

Yes, turn down fuel psi, its just wasting fuel, sending out the exhaust, you fuel economy will go up and you won’t notice any difference.

i am at 3100’ and run about 90 psi


did you read his thread?

Its cold outside lets talk Heaters, H81, H82, H83, etc.

I own an H82, bought from GL last January, and overall it seems to work well for my shop heating needs, but I was wondering a bit about the differences between these three models and what light you might shed on their history. I know they are all very similar, and were all build by Engineered...

www.steelsoldiers.com

 

[Smallblockfuelie]

thank you. I‘m around 500 feet so after reading the Tech manual on fuel pressure by altitude I didn’t pay much attention to adjusting fuel pressure down on my unit. I’ll do as you suggested, I do notice excess fuel burning at the exhaust.

yesterday I lost all fuel pressure. Today I’ll check the coupler between the pump and the fan motor and look for sediment/debris in the onboard fuel tank. The inline filter was ok and no moisture or junk was in the sediment bowl when the fuel pressure disappeared yesterday. I’ve become spoiled in a 60 degree shop and working in a t-shirt when it’s below 20 outside.

 

[jake1086]

Piggy backing on this post. I just acquired 2 H82s, no matter what I do I can not get any fuel pressure, zero. Read as much of the TM as I could relate to fuel, have held the purge? Switch on for minutes in vent mode, have hooked up external fuel supply to bypass the tank, cracked and bled lines. Any help much appreciated.

EDIT:
checked the fuel pump coupler, broken. So lathed out a new one. I've finally got fuel pressure! Wooo only 40psi. Adjusting the screw under the acorn but doesn't do anything I can see. And ... I get no fuel out of the pump on the tiny output line going to the burner. What gives?

 

[155mm]

are you checking and adjusting the pressure in the 'Fan' mode or 'Heat' mode?

you will have 40 psi on fan mode only and about 20 psi with the purge switch engaged in fan mode, there will be no fuel to burner also in fan mode, only return fuel to the tank.

to adjust high side pressure, it must be in heat mode

 

[155mm]

this shows fuel pressure as heat (90psi), then fan(25), then purge(15), then fan and back to heat

 

[jake1086]

this shows fuel pressure as heat (90psi), then fan(25), then purge(15), then fan and back to heat

Thank ya Sir, last night about midnight I went out in the shop to grab something and decided to flip it on. Out of curiosity I played with the return air temp dial, Diesel squirts everywhere from my disconnected supply line. I was so happy haha.

P.S. DO NOT START THESE INSIDE hahaha Luckily I was right next to the big shop door so opened that up to the freezing night air and let it vent out. Tonight I will play with fuel pressure, and try to get the smoke to clear up.

 

[jake1086]

Thank ya Sir, last night about midnight I went out in the shop to grab something and decided to flip it on. Out of curiosity I played with the return air temp dial, Diesel squirts everywhere from my disconnected supply line. I was so happy haha.

P.S. DO NOT START THESE INSIDE hahaha Luckily I was right next to the big shop door so opened that up to the freezing night air and let it vent out. Tonight I will play with fuel pressure, and try to get the smoke to clear up.

Update to my post, I could not get smoke to clear up, maybe it takes longer at a lower pressure for the smoke to clear? Anyways, I was not impressed with the heat output, I suppose these are designed to reheat air as opposed to heat the freezing outdoor air?

Oh side thought, I last played with it about a week ago, I could not see anything through the site glass after switching to heat mode. I thought the night before when I got it to kick off in my shop I saw a bright yellow ball off flame in there. Something's gotta be wrong still.

 

[155mm]

there should not be smoke after the first 1-2 seconds of heat run time, it will puff a couple seconds, not more than 3-4 when cycling on/off or when moving from heat to vent. I vent my heater exhaust to the 'storage' side of my shop and have no issues with carbon monoxide in the big side, unless my CO detector is faulty, which I dont think so bc it goes off when running in gas motors with doors closed.

just fyi, a diesel emits 1/28th less carbon monoxide than gas

these heaters have no problem running full cold intake air, I have an 82 heater for outside use only and there is no problem getting lots of warm air blown on you but I guess 80* air feels pretty good when its 20*
it sounds like it is flooding, or has an air blockage to the burner.
I would pull the burner and adjust the igniters, and clean the tip and inspect for FM. also inspect the air flap valves, they are like tin foil over the air intake holes
do you have a good blue spark in fan mode?
while you have burner out, inspect burn chamber for fuel and clean the inside of the inspection window

when you shut yours down, do you move the selector from heat to off or do you cool down the burner first? I highly suggest 'cooling' the burner down before powering off
is your K8 relay still mounted in OEM position? I have found on almost ever one of these I have worked on, that the K8 gets hot and trips when mounted properly, I have dismounted and let the K8 hang in the intake air with the cover removed

have you read this thread? https://www.steelsoldiers.com/threads/its-cold-outside-lets-talk-heaters-h81-h82-h83-etc.132138/