Auxiliary heater not working 6.1

[chockswahay]

Apart from the “heat immediately” runtime limit already described there is a TPI to replace the heater wiring loom on vehicles manufactured before June 2021.

The power wires cross section is not enough causing a voltage drop so heater shuts down due to undervoltage.

Mine was shutting down when leisure batteries voltage went below 12.2v, now it keeps running even below 11.8v. Check your wires, if power cable is 1.5mm2 instead of 2.5mm2 it must be replaced.

View attachment 112823

I have been having similar issue with my 2020 coast. Certainlyif the volts drop below 12v (as it does in the start up phase is batteries it full) it cuts out and won’t start. The other issue I’m having is that when it does work it keeps cycling on and off even on low setting which is noisy and draws down the battery even more! I’ve got the batteries charging so will have another look in a day or two. So far my experience of this heater is not good

 

[Benham]

VW Cali post on this:

Hi all, we recently had an issue running our Auxiliary Heater (2021 Coast) as follows:

• One morning we couldn’t start the auxiliary heater by either the ‘Heat Continuously’ or ‘Heat Immediately’ options. We tried several times, checking the obvious – Fuel, battery charge, vent obstruction, all to no avail. Eventually the Control Panel completely froze, stating ‘Error: Auxiliary Heater’. This ‘locked in’ various settings – Fridge etc.. which we couldn’t turn off. I note that people have had a similar issue with the Electric Roof. Fortunately, our roof, is the manual option.
• We tried our local VW Van Centre who had no idea and would only offer a ‘booked in appointment’ 5 weeks later.
• We contacted VW Assist who kindly performed the following works:

a) Via the diagnostic port, they noted the presence of a fault code which VW state is triggered following running the Auxiliary Heater via the 'Heat Immediate'/Remote Fob option for more than 180 mins, in a parked situation.

b) VW Assist explained that if this happens, VW advise two possible options:

- Use the Heat Continuously option and the Heater should work again.
- Drive the vehicle a short distance, after which the 'Heat Immediate' option should work again.

We had no idea of the 180 min ‘Heat Immediately’ limitation so when the Auxiliary Heater failed to start, we tried both ‘Heat Continuously’ and ‘Heat Immediately’ options. Neither worked and eventually the Control Panel locked up, displaying the error message mentioned earlier.

The solution to reset the Control Panel is unbelievably, by pulling a single 5A fuse. Do this with the ignition off, wait a minute or so, plug back in. The Control Panel should then be active again. On the 2021 Coast, the required 5A fuse is the single Orange fuse, under the passenger seat, on the row nearest the front of the vehicle (see pic).

VW Assist then proceeded to clear the error message, but I don’t this this was necessary to get the Heater Working again.

Regarding the Auxiliary Heater temperature settings, in common with other posts, we have to set this at either 9 or 10. I've no idea why VW can't calibrate/graduate this to utilise the lower numbers - maybe we are too soft!

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Thank you for sharing. I've just measured mine

Apart from the “heat immediately” runtime limit already described there is a TPI to replace the heater wiring loom on vehicles manufactured before June 2021.

The power wires cross section is not enough causing a voltage drop so heater shuts down due to undervoltage.

Mine was shutting down when leisure batteries voltage went below 12.2v, now it keeps running even below 11.8v. Check your wires, if power cable is 1.5mm2 instead of 2.5mm2 it must be replaced.

View attachment 112823

Thank you for sharing. I've just measured mine for peace of mind. All is good.