Webasto stops

[TheoSr]

On my Dartsailer I have a Webasto LO 2303.15 diesel air-heater. Must be from 1978 or so. Problem is, it starts correctly, green light on controlpanel, but after about three minutes of producing nice hot air, it stops and shows the red light. When I then put it on ventilation for 30 seconds, to cool it down, it will restart and quit again after about three minutes.

I have checked both thermostats in the heater, they are okay. The room thermostat is set at 30 degrees so that does not stop it.
The battery is new and full. I have installed new cables so it gets all the current it needs.
It takes its fuel from the main tank. The filter is clean.
I have not taken the burner out, as it does start and burn. I did check the plug.

I know it is an old beast, but (being Dutch) I hate to spend money if there is still a chance to repair it.
So any good advice is most welcome.

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[SPROUTZ]

I had a similar problem in the past with my Ardic heater which was due to the fuel pump.

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[mhouse]

Had the same problem with my Wallis and the air outlet was part blocked.

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[andy_wilson]

WHat does the book say the red light is about?

You could try running it whilst connected to a shore battery charger, or running the engine, just to make sure it's not low voltage.

My Mikuni wouldn't go through the full start up cycle when the batteries were low, but would run OK if I started whilst the engine was running (say while coming into port), then engine stopped it was OK for an hour or whatever we needed.

Current draw on start up is highest, dropping right off whilst the heater is 'cruising'.

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[TheoSr]

Red light indicates failure to ignite, system stopped completely.

I did try running it with running engine and with charger, no difference. Actually the heater was one of the reasons to install a new 120Ah battery. Plus checked all connectors for proper contact so contact resistance is now neglible.

So it looks like the only thing left to check is the fuel supply. Job for coming weekend.

Thanks for your input,
Theo.

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[TonyS]

Is there a filter in the heater, close to the burner. These tend to block especially if additives are used in the fuel. You would then be getting fuel starvation which would explain the symtoms.

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[robind]

Check the small filter at the pump just under the pipe connecting nut it may be blocked.
Rob

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