THERMO KING TRI PACK APU heater wont work

The heaters on Tri-Paks are notorious for the screens plugging and the burn tubes failing due to the crappy fuel. Odds are one of those items is your problem. Talk to a dealer about proper upkeep to get the most out of the heater or talk with them about going to kerosene for the heater. Kerosene burns cleaner and the heaters have less issues.

 

If you are talking the bunk heater, the service kit for that thing is $210 from Thermo-King. It comes with the new screen and a glowplug for the bunk heater.

It also has a new filter for the fuel pick-up that is on the frame rail by the fuel tank.

You do service this thing on a regular basis correct?

 

the bunk heater is not like you are used to.

On the frame rail, you should have a filter/pump for the heater.

You will hear the bunk heater kick in and start to blow and as it warms up, it may speed the fan up and then slow it down once the cabin is up to temp.

This has a glowplug that goes into a combustion chamber and it fires the fuel and that warms the air. Uses very little fuel to do it too.

I have not put my service kit into my heater. Not sure if I am going to this fall. It's working like a dream. But it's also 80 out this weekend and not sub-zero when it's likely to give me fits.

On the APU, look at the wire going to your starter and also on your Eng On switch AT the APU.. Mine just started acting up on me and would stop running once it started, it would die.

Both my starter wire and my Eng On Switch were corroded to the point they failed.

I have the service kit for them and there are two fuel filters AND an air filter. You may also have to put in a new idler pulley for the alt/AC comp belt. This is a known problem I found out on the older units unless you put the new idler on it.

I have put on a new compressor belt and still need to put my waterpump belt on. I was hoping to have done it when I put in new motor mounts, but ran out of time and it got scratched for now.

I am hoping to open up the APU again this weekend and do all of that work now.

 

why won't you put an APU in the new truck? just curious is all.

 

My heater works without running the APU......seems like it just runs off of the electric......

 

The newer TriPacs now have 120amp alternators, the originals were only 65amps, so running a microwave would kill your batteries over time. I have a new Evolution model, and have found out that the alternator is way too smart. It will only put out limited amperage when the AC is on, because if it was at full output, while the compressor was on for the AC, it would be too much load on the engine, and plug up the unit's DPF too quickly.

But to the OP's heater issues. The heaters do not like biodiesel or additives. Mine also does not like altitudes over 5000 feet. ThermoKing does sell a special high altitude fuel pump for the bunk heaters, but I did not get a price. They have also recommended running it on kersene for an hour or so when you change the filters and screens.