Webasto 3500 D overheating (1 Viewer)

[Evildoody]

A few weeks back, my Webasto heater developed a fault (F10) overheating, so I decided to take it to bits and attempt to repair it myself (probably just the overheating sensor as all inlet and outlet pipes are not blocked. Instead of just replacing the external overheating sensor I figured I have come this far so I may as well service the unit too (15 years of use without one service) :-



As you can see there is some soot and carbon build up and the burner mesh has seen better days!

I have never taken one of these things apart before, but it all looks pretty straight forward to me. One thing about these German units is that they are expensive and parts are expensive, I have had to purchase the following parts :-

Webasto Combustion Motor Reflector Foil | 9022102A
(old one had seen better days)

Webasto Exhaust Pipe 24mm | 36061296 | 90394a
(old one had surface rust and was split)

Webasto Air Top 3500 or Air Top 5000 Burner Kit 12v | 67984B
(comes with all gaskets, O rings and glow plug)

Webasto Air Top 3500 Outlet Hood | 98651B | 1320323A
(I damaged it taking it apart :-()

Webasto Air Top 3500 Air Top 5000 Overheat Protection | 97265A | 1322831A
(hopefully this was the actual faulty part)

Webasto and Eberspacher Combustion Air Pipe 25mm | 91562A | 36000006
(original combustation air intake pipe was also split)

In addition to the above I have purchased stainless steel bolts, screws and Jubilee clips - so when I put it all back together (starting tomorrow) I should not have rusted bolts, screws, clips etc. if I ever need to take the unit apart in the future.

PS. The only video I found that was helpful and related to my actual unit was in Russian :-

 

[Evildoody]

More progress made today :-



Old gaskets removed, new O-Ring fitted, new Burner tube inserted, burner top plate fitted, new gasket fitted and casing reassembled. Now need to fit heat exchanger, overheat sensor, control box, reconnect wiring harness and plastic housing. Then need to connect it all back up and see if it works . Job for the weekend, wish me luck.

 

[Evildoody]

Unit refitted, replaced all bolts and jubilee clips with stainless steel ones too, will make the job easier should I ever have to remove the unit again. I also extended the wiring harness.
I had the unit running for over an hour without issue, so all should be good.



I still have some cables to tie wrap in place and I need a new silencer and 90MM heat pipe as they are knackered too.

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[irnbru]

I hope you don't have a dog. Ours kept going faulty with our last van but it was the dog lying in front of a vent blocking it.

 

[Evildoody]

I hope you don't have a dog. Ours kept going faulty with our last van but it was the dog lying in front of a vent blocking it.

No, no dog. Definitely a sensor fault in this case. I'd be really upset if I had gone to all this trouble and the issue was caused by my dog