Anyone have a 2010 model Scholastic Webasto heater?

[bustagator]

I posted about this a few years ago but never got it working. Giving it another stab now.

I've got a 2000 Thomas Saf-T-Liner MVP that I bought from the Montgomery County school district around 3 years ago. Finally got it completed enough to get it retitled as a RV and insured. Yay! I still need to update my build thread on here, got lots of pictures of the process.

We are planning on heading west in January and having some form of heat in the bus by then is a priority. The Webasto Scholastic heater that came installed in the bus is my best bet at the moment, but it won't turn on.

The "instaheat" button near the drivers button lights up red when I push it, and there is a clicking sound from the Webasto unit about 30 seconds later - and that's it. The red light screen near the drivers seat turns off about 5 minutes later.

I have the maintenance records for the bus, and the very last one (2 months before the bus was taken out of service) says "heater - pipe" and has a notice to service it. There is a brand new exhaust pipe installed on the heater, which leads me to think that there is no good reason for the heater not functioning as it was looked over right before I got it and it has never turned on.

Anyway, I've made sure the red safety button is pressed down, and checked the fuses, which leads me to the actual question I have for anyone who has the same model heater:

What are the fuses in the little fuse box at the rear of the heater supposed to be? There is currently a 15 and 10 amp fuses in the box, with an empty slot to the far right. There appear to be wires running to the empty fuse slot so I'm wondering if there is a fuse missing. Can anyone tell me what fuses go in those three slots? The documentation I've found online (which I'm like 50% sure is for my model) has a 15, 15 and 20 going in the bays, which adds to my confusion.

I'm prepared to start replacing the other inline fuses and testing the individual parts but I wanted to make sure I have the right fuses in there first. I've attached pictures of the heater and the fuse bay, along with a couple of shots of the completed bus for those interested.

 

[Jolly Roger bus 223]

Sorry, I don't know anything about a Webasto heater specifically but I have and do work with many different style and design of gas fired equipment.
With that over with.
If you hear the clicking then that means that your igniter is working and most equipment has a safety built in that tries the igniter to fire the unit 3 times and then locks out the unit until power is turned off and back on as a reset.
The igniter sparking and the heater not firing tells me either it's not getting the gas to fire off.
There could be a strainer before the gas solenoid valve that is stopped up.
The spring in the solenoid valve on the entering side could be hung up and needs to be cleaned.
The burner orifices which are usually the size of a sewing needle could be corroded over and need to be cleaned.
The missing fuse is a concern because it could be the one that controls the circuit board the controls everything.
If you haven't heard it yet?
You should hear a fan/blower come on at least a minute before you hear the igniter click if you don't hear the fan first.
I would start there buy turning the gas off and sticking a fuse in that empty slot and turn the power back on not the gas hit your on demand button and see if your fan comes on.
If not then shut the power off and pull the fuse and see if it's blown.
If it is then you have a bad fan motor or wiring between the motor and controller.
Either one will stop the gas valve from opening because the controls didn't see the fan do an air PRE-PURGE before ignition.
If it's not then I would look for a new control board?
Blow all of your gas lines out and make sure you have gas to the unit
I can but won't at this point to tell you how to work on a gas solenoid valve but if you can find a manufacter name and model number on your valve I can help you find it on the computer or I can post pictures of the troubleshooting and or the complete re-build instructions that they don't really give out the public and if you do need that then it's cheaper and quicker for you to buy a new one.
Let me know if I can help

 

[bustagator]

Thanks for the tips. I put a 20 amp in that bay and now it fires up the pump, but still doesn't ignite the fuel. One step closer I suppose.

 

[Jolly Roger bus 223]

Sorry.
I kept referencing gas but the fuel oil appliances use the same safeties as I mentioned plus other issues.
I was questioning the size of that missing fuse for what I was trying to explain and it still seems a little big for it?
But for fuel oil there is/should be a pump to push/pull the fuel to the heater.
The fan before and after the firing is still important.
But with fuel oil you can have the same problems you will have with your bus engine after not being used for years.
Filters stopped up,fuel,gelled, mold,mildew plugging everything up, or the heaters fuel pump return line plugged up or a valve closed in the return line (the only valve that should be a choice in a fuel return is a check valve. If there is a shutoff valve then make sure it's open and hide the handle)That will blow a fuel oil pump seal in a heart beat and most unit direct mounted pumps you won't know the seal/internal seal is messed up until you have been through everything else I have mentioned unless you have a way to read the fuel pressure on either side of that pump.
I guess I need to shut up until I look into exactly what you have? I will.

 

[Jolly Roger bus 223]

It might be me and my computer but I can't see the model,make info? If you type the specifics I will try to help but not getting the fuel because of the filter ,clogged lines, could be it.
Disconnect the fuel supply line leaving the pump and stick in a cup or bucket and make sure the pump is pumping the fuel.
It's not hard to see what a pump that is (scenario) supposed to do 5-gpm only do 1-gpm? Your pump is slot less and probably measured in seconds but a gallon milk jug and stop watch will be your best friend for that test

 

[BlackJohn]

It could also be a dirty nozzle that won't let the diesel pass to the ignition chamber. Just like any oil furnace has.

Good luck with it.

John

 

[bustagator]

Thanks for all the ideas. Everything is working with the fuse in, except it just isn't igniting the fuel. I also cannot smell any fuel when it is trying to ignite either. I went out and got a new fuel filter. I just take the old one off, top up the new one with diesel and screw it back on right? Never changed a fuel filter before.

If that doesn't do it I'll pull the line where it connects to the heater and see if there is fuel. Anything I should check for when I'm replacing the filter?

I'm really happy that it's at least trying to start now. No fuel is an issue that can be fixed

 

[bustagator]

Oh, and it's a Webasto DBW 2010.80 heater.

 

[BlackJohn]

You may have some air in the line from the filter to the burner too. If you can remove the igniter to check its condition, might be wise to clean it up. Just clean with a fine file or emery cloth for a better spark.

John

 

[2kool4skool]

https://www.webasto.com/fileadmin/w...ta-Sheet/usa-heavy-duty-datasheet-dbw2010.pdf

http://www.techwebasto.com/documentation/heater/offhighway/dbw-2010.html

 

[Twigg-SKO]

Does the heater run from the main diesel tank or have its own?

If the main tank, then is there enough fuel. Typically they won't run if the gauge is showing 1/4 tank or less, to save you from being stranded.

 

[Gaffobohs]

If you haven’t changed the fuel filter already, go ahead and do it. Will probably find it’s empty or half empty and the webasto isn’t getting any fuel. Seen this many times


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