Espar bunk heater not working when below 0 degrees

Does it smoke when it starts up, when it is working normally?

If no then I would just suspect it could be the fuel line gelling up. You can also check the fuel pump as well. You should hear it clicking/pulsating outside the truck . I had one that would get gummed up over time with the crappy fuel nowadays.

If it does smoke alot when starting then you will have to take it apart and clean it, burning off the excess carbon build up inside the burn chamber, there is also a glow plug element in there that can go bad as well..

but if yours stops working only when it's really cold it probably just the fuel line getting gelled, maybe if you can find something to insulate it or wrap around the line , it may help

 

When I had them on the trucks we would drop the fuel line into kerosene/fuel injector mix and run for an hour. Burn everything out, no more smoke when it started.

 

I have a bunch that freeze up when it hits -10ºF, it is always the fuel that gells up.

As for blowing out the carbon, you can't, they have to be removed and cleaned, you can get a lot of carbon out, but it never cleans it out completely.

Preventing the buildup by running them hot and doing so every month of the year.

 

More than likely gelling in the line. My gen set was doing the same at 10 degrees. No treatment in fuel.

Solution - bottle of Howes in tanks.

 

Like others said fuel in line gelling is most likely. Bottle of howes or if its still an issue try some heat tape and/or insulation around the line. Otherwise it may be gummed up and need a deep clean.

 

I run kerosene exclusively. Knock on wood. No gel up yet.

 

I'm in a Freightliner with 140,000+ miles and my Espar bunk has went on strike. A nice Freightliner technician arrived and informed me that there is a national campaign going affecting 37,000 vehicles.

The common culprit seems to be the two foot length of tubing drawing fuel from the tank.

Maybe you can have your issue fixed at no cost to you.

Update:

The thick plottens.

 

I would get on Ebay/Amazon and get a 2 or 3 gallon tank for one of the cheap Chinese diesel heaters. Mount it on your catwalk. Keep kerosene in it or heavily anti-gel treated diesel and drop the line into it instead of the main tank when it's super cold out.

 

I had a new Western Star that had the same problem. After trying a lot of different things, it came down to the wiring.
The dealer wired it through the trucks low voltage disconnect which didn't have a heavy enough gauge of wire to supply the heater, too much of a voltage drop. Worked fine at warmer temps.
I wired it directly to the batteries using the called for wire gauge and it worked great after that.