Couple of H82 heater Questions

[Isaac-1]

I just picked up the H82 heater I won from GL last week, it is nearly identical to the Army H83 only real difference is the plug and the soft start assembly.

Anyway, I picked it up, put some diesel in it and it seems to fire up and run. The hour meter shows only 2 hours of run time, I don't know if this is right, overall it appears clean, but does have a couple of dings around the duct connectors, plug has been changed, and when I first turned it on I a cloud of black soot / carbon build up rained down for about 15 feet in all directions thick enough to nearly coat the top of the heater. Also the sight glass is nearly obscured by soot. (it did not come with ducts, but I found some NOS military surplus ones that are the right size but wrong NSN on ebay for a somewhat reasonable price)

First question, is this normal, and should I expect it again in the future?

Also I think the Off/Vent/Heat knob may be messed up, it is a spring snap to position style switch, off is at the 12 o'clock position, however when switching to vent it ends up at about 4 o'clock and then heat is at about 7 o'clock, and switching back to vent lands around 2 o'clock. Has anyone else seen this? Also switching back to vent for cool down seems to sometimes kill the unit, and the switch must be wiggled to go back into vent mode and restart the blower.

thanks Ike

 

[MusgroveM]

The switch, on mine, is definitely 12, 3 and 6. When it started getting cold around here, I started running Kerosene. the soot went away and burned half as much fuel. The TM calls for 125PSI do you have the correct pressure
Thanks
Mike

 

[epitts]

I first turned it on I a cloud of black soot / carbon build up rained down for about 15 feet in all directions thick enough to nearly coat the top of the heater. Also the sight glass is nearly obscured by soot. (it did not come with ducts, but I found some NOS military surplus ones that are the right size but wrong NSN on ebay for a somewhat reasonable price)

First question, is this normal, and should I expect it again in the future?

Also I think the Off/Vent/Heat knob may be messed up, it is a spring snap to position style switch, off is at the 12 o'clock position, however when switching to vent it ends up at about 4 o'clock and then heat is at about 7 o'clock, and switching back to vent lands around 2 o'clock. Has anyone else seen this? Also switching back to vent for cool down seems to sometimes kill the unit, and the switch must be wiggled to go back into vent mode and restart the blower.

thanks Ike

Keep in mind mine is a H-81 almost the same. Mine did not have any soot on start up nor has it had any since. My switch will some times go past the vent selection at 3 o'clock and end up a 4. But I just give it a little twist towards the 6 o'clock and it pops right back. Mine runs about 100 to 110 psi on fuel. TM says it should be at 125psi. Mine had 1.1 hours on pick up.

 

[Isaac-1]

I ran it in the shop building on the family farm for a couple of hours today while I was working on my MEP-003a, even test ran it powered by the MEP-003a once I had it back together for a few minutes. I had a little raining soot on initial start up and a bit more on cool down with just the occasional flake during the main portion of the run. Overall did good considering I had the roll up door open about 4 feet, since I don't have the ducts for it yet, the H82 was just far enough out the roll up door for the exhaust stack to be outside and above the roll up door (it is a metal shop building and roof is about 18 feet above floor level so I was not worried about hot exhaust getting to anything. Fuel pressure is probably just a little low reading just over 120 psi, also I should probably put a new plug on the cord or replace the cord entirely as it has a couple of cuts through the outer jacket (one through the green ground wire also showing bare copper) and the non original plug is tarnished and gets warm at the outlet, for now I have wrapped the cuts in electrical tape. I will probably stick with running it on diesel for now since we have a 1,500 gallon tank at the farm, but may check on getting some kerosene from our diesel supplier if I find I use the heater enough to justify it as I have a 450 gallon skid tank that is not currently being used.

Ike

p.s. what is the point in the little loops of metal cable going to the top of these units, mine is missing all 4 of the top bolts, one of the cable loops is broken the other 3 have both ends attached to the side bolts. It also appears that someone has repaired a broken spot weld on the frame.

 

[MusgroveM]

I think Eric might be on to something with the lower pressure. An incomplete burn may be too much fuel pressure. That would cause sooting. The TM calls for different pressures for different elevations and different fuels for different out door temperatures. It may be that you need to lower your pressure. A couple other things that might cause a dirty burn is a dirty nozzle or fuel to air ratio.
The four bolts holes and loops are to stack them. There are corresponding holes in the bottom of the unit. Set one on top the other and loop the cable around the frame and reinstall the bolt.
Mike
ARMY TM 5-4520-256-14