Club 80-90 Forums

Does anyone have any experience with this type of heater? Its a auxiliary water heater. Petrol type.

I think my glow plug may be broken.

It keeps blowing fuse 1 of the webasto loom.

I have taken the heater out and checked the water circulation pump within the webasto. <works OK>





The flame detector doesn't blow the fuse nor does the water pump.

That lead me to the glow plug.

Upon inspection it seems very loose within its port.
I wondered if this could be why its blowing the fuse?

Any clues?

Depending on your heater the fuse F1 should be 15, 20 or 25A looking at various wiring diagrams.
Fuse F1 does seem to protect the glow plug/nozzle heater on most models.
What fault code do you get?
If the system is operated with a switch, the nature of the fault is indicated
by a flashing code on an indicator light during the run-on time of the
heater. After five short signals, count the long flashes. The flashes
correspond to the number in the table below:
F 01 No start
F 02 Flame failure *
F 03 Undervoltage or overvoltage
F 04 Flame simulation identified during start-up or shut-down
F 05 Flame detector defective
F 06 Temperature sensor defective
F 07 Solenoid valve defective
F 08 Blower motor defective
F 09 unused
F 10 Temperature limiter defective / Overheating
F 11 Ignition spark generator defective
F 12 Fault lock-out due to repeated malfunction or
repeated flame failure
(8x no start-up or 5x flame failure)

Check the resistance of the glow pin - I think it is the same one as used in the Airtop 2000 and the resistance should be 1.2 to 1.4 ohms. (Across the two yellow wires.)
Failing that you could take out the glow pin and check it with a 12v battery across it to see if it works. If they are carboned up they can be a bu**er to get out in one piece and are expensive. But if it is loose as you say it may well drop out!

The thermo top T doesn't have a fault code system to my knowledge.

I have the plug out and it looks clean.

Should it be loose in the tube it sits in? Mine doesn't seem very secure at all.

So its a 12v plug is it? Some are much less? don't want to make it worse by throwing 12v across it!

F1 is the fuse that blows, that's the fuse that relates to the water pump, flame detector and glow plug.

The reason I question the plug is that only when this is connected does it blow.

I'll check the resistance across the yellow wires.

Thanks.

The glow pins are either 12v or 24v depending on which model /system you are running. They should be a firm fit in the hole.
That pin looks a little short to me - it may be correct though. Airtop2000 one:



They all will have a fault code system - it just depends upon which controller you use as to whether you can see it or not.

How do i find the fault code then?

It does not work on a switch, it works on a lcd single event timer.
This isn't effected by the fuse blowing and still reads "on" even when the fuse blows. Nor does it flash!

?

Your timer/control doesn't support it then.

No my clock doesn't have a fault reader.


It would be handy to know exactly what the problem is.

Is there another way of reading the fault code?

I'm guessing the different lengths of glow plug are due to the fact that the longer one is an air top and the shorter one a thermo top.

It was working perfectly up until very recently.

I can hear a constant clicking on start up which i'm guessing is the flame detector. <if the fuse doesn't blow>

Have you tested the glow pin yet? You only need a short burst of 12v to see if it glows if you don't have a multimeter to check the resistance.
The clicking noise should be the fuel pump priming the heater.
You would need an obd2 reader and the webasto diagnostic programme or a different timer control to read it.

Thanks.

Ill try the glow plug tomorrow but i expect it to work.

Its why it blew the fuse that I cant understand.
Like I say, the glow plug felt loose in the port. You could twist it by pulling the wires. I'm wondering if its shorting out?

I do have another type of timer so i guess i could use that to read the fault code but I will need to adjust the loom to the lcd display as it has different connections etc. And even then it may not read the fault codes.