Hi all,
The fully working parking heater in my ZT-T seems to run on when I turn the ignition off when I arrive home at night. At and before this time, the heater has not been actioned via the remote or the programmer.
There is the noise of the pump running from the Webasto unit and, due to the cold weather, exhaust is visible from the pipe coming from the bottom of the unit. This pump noise continues for about 5 minutes or so before shutting off.
I get the impression that the heater is perhaps being activated due to the outside temperature having been so low.
This, I believe, is the case for cars fitted with the parking heater but no remote or programmer fitted. I seem to recall that the heater comes on when the temperture is below 5 degrees.
I am concerned that the heater is running unneccessarily and using fuel when it should not be running. Fuel consumption is only about 37MPG so perhaps I am wasting some with this pump running.
Any ides guys?

The FBH normally takes a couple of minutes to shut down at exceptionally low exterior temperatures even when the engine is up to full heat and after you have switched off the ignition. When exterior temperatures are slightly higher than the recent cold spell the burner will usually shut down before the fully heated up engine is switched off, unless you have activated the parking heater with the remote which has a programmed default of 30mins.
A certain amount of exhaust smoke is quite normal during shut down or start up of the boiler which again is more prevalent at cooler temps.
I don't think you have an issue. However, I would check after an hour or so just to confirm the FBH is not still running and flattening your battery.
Some folks have reported issues with the MG Rover FBH circuit board failing leading to running all the time triggered via the K-bus eg when opening a door. The Landrover version is I believe the better and more reliable circuit board to have if you have to replace the FBH in future.

 

Thanks for the info, lovel.
It is strange to find it running when turning the ignition off when I have not actioned it in the first place. It does only run on for about 4 or 5 minutes. During the time it runs like this, the air con display is not lit up as it would be were I to have switched it on during the journey or scheduled it to run at that time.
One thing I forgot to check was whether the dose pump under the back seat area was making a noise while the unit was running. I will need to check.
I must say that the Webasto has been of great benefit during the weather we have had. Getting into the car when the unit has been running at a scheduled time has been great and no need for window scraping.
I've become a Southern Softy !

 

i think ours just runs the pump not the actual fbh after ignition being turned off

 

Yes, I think you are right, Carl.
There is operating type vibration comes from the actual Webasto unit while it is 'running' at this time so it is more than likely the water pump part running on for a short time intentionaly. It takes the form of a constant high pitch noise which then shuts off after some 4 minutes.
Cannot understand why it needs to run on though. Seems a bit superfluous.
JEK

 

Yes, I think you are right, Carl.
There is operating type vibration comes from the actual Webasto unit while it is 'running' at this time so it is more than likely the water pump part running on for a short time intentionaly. It takes the form of a constant high pitch noise which then shuts off after some 4 minutes.
Cannot understand why it needs to run on though. Seems a bit superfluous.
JEK

The burner goes through an air purging cycle to clear unburnt fuel from the burner chamber because the gauze in the burner housing gets saturated with fuel, if it didn't carry out this air purge shut down cycle it would be even more smokier next time it was started up which would tend to make bypassers think your car was on fire. Might also shoot some flames out the end of the exhaust pipe too!!

 

so its the air intake fan running then

is going to go for the pump running to cool the unit after use

 

As said, it runs the fan for a couple of minutes after it turns off, to burn off any excess diesel from the heater surface and to help cool the unit after operation.

Quite normal to hear it for a couple of minutes after switch off.

Regards, Rob.