Fuel Burning Heater

[Chas2008]

Today, using a page from the Webasto Thermo top C E & Z Installation Manual I set about testing the Combustion Air Fan and the Circulation Pump to check their operation.
Why, because my FBH is not operating as it should. When pin 3 is earthed the Water pump runs for 124 seconds then stops, no other activity happens.
The PCB has been repaired by FrenchMike, a new Dossing pump has been fitted and primed, and a new Landrover Temp Sensor has been fitted inside the front bumper.



In the diagram above, X5 is the Circulation pump power feed and X4 is the Air fan feed.
These are the same as the labeled picture below (thanks to FrenchMike)



Both the Air fan and Circulation pump powered up when given a 12v feed.

Why then won't the FBH fire up and run normally when powered up?

All posts I can find on the forum say that when powered up the Air circulation fan kicks 1st, not so in my case.

Other than taking the PCB out and returning to FrenchMike to be checked again I'm at a loss.

Has anyone any thoughts on this please?


Charles

[Avulon]

If yours is the 98570 then shouldn't you be earthing pin 3 to make it run? You say in your post that you are connecting it to +ve (I assume battery +ve)?

[Chas2008]

Yep I stand corrected, I was earthing pin pin 3 as was required, slip of the tongue.
Will edit post to correct mistake.
Thanks for the spot Avulon.

Charles

[Avulon]

No problem, thought it best to verify that your were indeed using the right test method. I assume you've tried pulling fuse 8 to reset? I haven't had the board out on mine so don't know how it connects to the rest of the heater, If you sure that the board is connected well then it must be the board still at fault. I'd PM FrenchMike with your problem and see what he suggests.

[Chas2008]

Yes have to pull fuse 8 out regularly to reset. Think I'll have to take it out altogether, dismantle, clean and check everything and contact FrenchMike.

Charles

[macafee2]

Charles I cant help with advice but I would appreciate a copy of the circuit diagram in your post? would it be possible to let me have a copy?

Thanks
macafee2

[chas_1]

Hi Charles,
I am no expert on the FBH but mine was not working so i followed French Mikes guide on a reset and mine FBH is working fine(well with pin 3 grounded not cold enough yet for a proper road test) I think you disconnect 6 pin connector then disconnect 2 pin connector(power?) reconnect 2 pin connector then connect 6 pin connector this resets whole system.Hope this helps.

Chas

[Chas2008]

Originally Posted by macafee2

Charles I cant help with advice but I would appreciate a copy of the circuit diagram in your post? would it be possible to let me have a copy?

Thanks
macafee2

Hi macafee2,

The quick and simple way to get a copy is this:
- using your pc mouse, right click on the image, a menu box opens up
- move cursor into the box, move down to "Save Image As..." left click here
- a Save Image window opens up in which you can tell your pc where to save image, rename it etc

Hope this helps

Charles

[jbafourcandles]

Hi just been on Butler Technik web page they have repair kit for thermo top heaters.
http://sales.butlertechnik.com/webas...n-kit-9017813b
hope this will help some one

[Snagger]

Originally Posted by jbafourcandles

Hi just been on Butler Technik web page they have repair kit for thermo top heaters.
http://sales.butlertechnik.com/webas...n-kit-9017813b
hope this will help some one

That a great find duly bookmarked for future reference.

Snagger.