Webasto help please

[Emer]

Hi, wondering if anybody has any info on an issue I'm having with Thermo Top C heater. New install to a camper, Using manual switch to turn on. When I turn on the heater all appears fine exhausting fumes, heater is burning fuel after about 30 seconds a pause, internal fan on, then exhausting smoke again burner stays on for about 10 seconds then off, heater will stay on for a further 2 mins with no burner then stop. Tried on/off about 30 times same thing. Manually purged fuel pump. Pump not clicking during start up. Two plugs X1 and X2. Wiring. X1, PIN 1 SWITCH LIVE, PIN 5 NEGATIVE, PIN 6, TO PIN 1 FUEL PUMP X2, PERMANENT LIVE PIN1, NEGATIVE PIN 2. FUEL PUMP NEGATIVE PIN 2 Is the diagnostic software hard to get?
Any help appreciated
Thanks Paul

 

[pcatterall]

I deal with Eberspachers not Webasto but some basic principles are the same. Im not following the various phases that you detail. Smoke can occur when fuel has been pumped but not ignited. You say that the fuel pump is not clicking during start up? that could be important as it should be. Usual start up is that the ecu checks that all the parameters are in place, starts fan, heats glow pin, starts to pump, fires up!
having to 'purge' manually should not be required, even if there is a lot of pipe with no fuel the pump should eventually get fuel through. I always recommend testing a new heater on the bench where it is easier to diagnose faults. Report back on the pumping issue and we can take it from there!!

 

[Boater Sam]

Battery voltage dropping or voltage at the heater dropping due to poor wiring or connections.

 

[Paulkenn]

I deal with Eberspachers not Webasto but some basic principles are the same. Im not following the various phases that you detail. Smoke can occur when fuel has been pumped but not ignited. You say that the fuel pump is not clicking during start up? that could be important as it should be. Usual start up is that the ecu checks that all the parameters are in place, starts fan, heats glow pin, starts to pump, fires up!
having to 'purge' manually should not be required, even if there is a lot of pipe with no fuel the pump should eventually get fuel through. I always recommend testing a new heater on the bench where it is easier to diagnose faults. Report back on the pumping issue and we can take it from there!!

Thanks for the reply, my description could be a bit off, I start the heater white smoke from exhaust about 30seconds, pause, fan goes on, more with smoke about 5-10seconds, no smoke from exhaust heater stays on for a further 2 mins then stops. Thanks Paul

 

[pcatterall]

Yes Paul, sounds like a typical 'non starting' scenario! The white smoke is just unburnt fuel being blown out. If it keeps blowing out white smoke when you try to start then maybe fuel is getting in but not firing up.
Please confirm if the pump is working. If you can hear it pumping can you disconnect the fuel pipe where it enters the heater? is it pumping fuel.
The most common non start situation occurs due to poor battery power, cabling or connections, you need to check the voltage AT THE UNIT!
Are you sure the heater works!

 

[Paulkenn]

Yes Paul, sounds like a typical 'non starting' scenario! The white smoke is just unburnt fuel being blown out. If it keeps blowing out white smoke when you try to start then maybe fuel is getting in but not firing up.
Please confirm if the pump is working. If you can hear it pumping can you disconnect the fuel pipe where it enters the heater? is it pumping fuel.
The most common non start situation occurs due to poor battery power, cabling or connections, you need to check the voltage AT THE UNIT!
Are you sure the heater works!

Thanks for the info I will check all wiring and pump and feedback, much appreciated. Paul