webasto heater not working

[lbivens]

webasto heater only works when ignition key is on. Any suggestions? 

[wolfe10]

lbivens,

Welcome to the FMCA Forum.

Any new batteries/changes in wiring immediately before this happened?

The heater should be wired to the HOUSE battery-- sounds like it is currently wired to the chassis battery through the IGNITION SOLENOID.

[wildebill308]

Welcome to the forum. You might look hear.

https://www.techwebasto.com/

Bill

[lbivens]

Thank you, but it was working the last time I used it and there has been no change in the battery situation. One of the switches does not light up anymore, so I am thinking it may be a switch. 

[wildebill308]

I would check the fuzes to.

Bill

[manholt]

Welcome.

When was the last time you used it?  Is the Antifreeze level where it should be?  If your not on shore power, turn on generator.  Check your cb on inverter.  What switch?  Are you on a 12V or 24VDC system? When was it serviced last?

[richard5933]

If it only works with the ignition on, then I would think that your system is plumbed with a loop of radiator anti-freeze running through a heat exchange which allows engine heat to be used to make hot water.

Sounds like the engine heat side is working, but for some reason the system isn't igniting and making its own heat. That would explain why it's not working off the house batteries. After checking the fuses (some will be located at/near the Webasto unit itself), run through the troubleshooting steps in the manual.