H-1 heater questions

[jdr2710]

I just picked up this Model H-1 heater nsn: 4520-01-135-2770 and was wondering if anybody could point me towards a tech order or some such.

It ran fine when I inspected it, tho it was hard to start. I also ran it for several hours the same day when I got it home (still hard to start). I'm going to use it to heat my barn, so after sitting for a couple weeks I got the duct-work & exhaust all set up and tried to start it last night. It gave me no love when attempting to start it. I used the prime port to feed some diesel in which worked fine, but once it used up what I was feeding in the prime port it wouldn't stay running. I'm guessing it needs to be primed/bled.

I'd appreciate any help/information anybody could provide as to the starting procedure (it does have the steps on the access panel which I followed) and how to bleed, plus any suggestions on why it is losing its prime.

Sorry for the poor pics, it was late & I was taking them in the dark.

Thanks,
Jeff

 

[jdr2710]

I thought I should get back to this thread as I've gotten the heater to run pretty consistently now.

The bleeding was pretty easy, tho I must have an air leak somewhere as it needs to be re-bled pretty much every time I run it after it sits for a week. To bleed I pull the air-diverter cover off to get to the injector and crack that fitting & crank for a minute or so until I get a good flow. Since I figured out to use the de-compressor lever to allow it to spin faster this goes pretty quick. I use the prime port on the head to shoot in a bit of diesel and I use the intake pre-heater, with this combination it fired right up after a night when it was 18 degrees outside.

The first time I got the engine running decently I couldn't get it to ignite the heater, so I took out the four engine mount bolts so I could shift the engine a little bit backwards to get the fan out. That went off without a hitch and I was able to clean about 2 cups worth of oily black sooty goo out from the burner area. With that all cleaned up it lights up instantly now, and runs clean.

I've been using this heater to heat my un-insulated 40x60 barn the past couple weekends and I'm quite happy with it. I've had the barn up to around 62 degrees while it is 30 outside.

Later,
Jeff

 

[jdr2710]

So after lighting instantly several times & running about 20 hours total I tried to fire it up a couple nights ago and no joy, well a little joy, the engine fired right up with no bleeding, but the burner wouldn't light. I pulled it apart again to check the burner area and it was well and truly gunged up again.

Does anybody know what the expected service interval is? I'm going to try a new fuel filter, but I'd think that if it were plugged it would just stop passing fuel not go into a bypass mode like an oil filter.

Thanks,
Jeff

 

[epitts]

Try running K-1 fuel and see how it runs.

 

[jdr2710]

I'll have to give that a shot.

Another thing I got to wondering about is the altitude adjustment it has in the fuel flow. Being that my house sits at about 7,600 feet I wonder if some adjusting of that might change the fuel/air mix and allow it to burn more cleanly.

Thanks,
Jeff

 

[epitts]

Another thing I got to wondering about is the altitude adjustment it has in the fuel flow. Being that my house sits at about 7,600 feet I wonder if some adjusting of that might change the fuel/air mix and allow it to burn more cleanly.

I would think that would make it run very rich, also what is fuel pressure.

 

[jdr2710]

I finally got the parts to fix the ignition coil (after getting a quote from Dyna-Curtis for $450 each!!)

I pulled the end cap off and found the circuit board completely embedded in some nasty rubber that was a bit of a pain to get picked out. I eventually had to do both sides which made the soldering quite a bit easier.

The parts I replaced were the transistor with the broken off leg on the top side, the 555 timer chip, and the main power transistor on the back:
TIP49 NPN Silicon Power Transistor from ElectronicGoldmine
TIP563 from e-bay
555 chip from amazon
I tried the obviously bad transistor with the broken leg, but got no spark, so I figured I'd shotgun the 555 chip and the big final stage power transistor. The two transistors were no longer in production, and while I'm sure I could have cross-referenced them I just paid a bit more for the new old stock.

With this repair it fired right up again. The engine has been running very well also, one squirt of diesel into the primer & run the preheat for a while and it started right up at 28 degrees yesterday, and ran all day long heating the barn to 62 degrees despite strong winds.

 

[jdr2710]

Now that it is cold again I'm fiddling with the heater once more. The parts that fixed the ignitor lasted for about 2 starts, leaving me to guess that the transformer must be bad. I checked the electronics with a scope and had a nice big 150Volt spike feeding into the transformer, but it wouldn't ignite. So rather than buy the $450 original ( I only paid $500 for the whole heater!) I thought I'd try a simple AC transformer style ignitor used on oil burning furnaces for $40 ( Carlin 41000S Electronic Ignitor from amazon ).

I have electricity where the heater is so I just wired a switch to power the transformer and used the chop saw & lathe to cut apart the old ignitor so I could reuse the wire that feeds into the combustion chamber. The transformer section was pretty nasty to get through, lots of gnarly hard plastic goo cast in around the transformer, but by taking a little off at a time I was able to expose the end of the socket and solder on a connector.

I got some high voltage rated wire (20kV) to connect the new transformer to the old socket and fired it up. With the external AC switch I just fire up the engine and once it is running well flip the switch to get spark, push the button to start the fuel and once it is burning, turn off the transformer. It has worked fine 6 out of 6 times so far!

The transformer has mixed reviews, but it is supposed to be a continuous rated unit, so running for a minute each time I fire up the heater it should last for a long time. If I find I need the heater to be completely stand-alone I'm thinking I'll just get a cheap inverter to run the transformer.

 

[jdr2710]

12 for 12 now! The new AC ignitor transformer really seems to have done the trick.