Hi all,
Car is a 2007 3.6 tdv8 Vogue. I have been trying to use my FBH to preheat the car these last few weeks, both with timer and remote. It generally shuts down after only a few minutes of running, even though it does fire as it should. What could cause this? Does the car monitor battery voltage, shutting down the fbh to make sure there is enough juice left to start the engine? I thought this might be the case, so the other day I left the car on a charger overnight and next morning the fbh worked fine. I thought I'd cracked it, but today, to make sure, I jumpered the car to a known good battery before firing the heater, but again it only ran for a few minutes. I'm confused.
I guess my number one question is whether the system does shut down if it senses battery voltage going low. If there is no such protection, what could be the cause of my problems?

Thanks!
Henrik

Hi Henrik, have a read in the wiki on here, under info. It appears the fbh will not work below a certain voltage.
So you need a good battery to start with.

My FBH works well when the engine is running but shuts down within a few minutes when engine is off. I haven't done any more checks but I'm pretty sure the water pump in the FBH is seized. When the engine is running, there are sufficient circulation thru the FBH but when the circulation stops, the FBH overheats and then shuts down. "Plentraktoren/Garden tractor": 2008 L322 TDV8
"Project": 1990 90 County 300tdi

Search for Rover 75 - there are links on here to a great diagnostic thread by a FBH expert

Firing, running and the shutting down is usually a seized water circulation pump - this is a secondary pump which is not used when the engine is running 2007 Zermatt Silver TDV8 Vogue SE - now sold but was a great car!

This one is a good start, there is also lots of other info

http://www.the75andztclub.co.uk/forum/showthread.php?t=71982 2007 Zermatt Silver TDV8 Vogue SE - now sold but was a great car!

Thanks for the input.
I have been reading all I've been able to come across, but I'm still in the dark. Battery has now been replaced with a new one, but still I only get about 9 minutes before it shuts down. I suppose it could be the aux water pump, but I would expect it to overheat in much less than 9 minutes if the coolant wasn't circulating. Maybe natural convection / siphoning action cases some circulation? It shuts down just as it's starting to blow properly warm air.

Any more tips are most welcome!

Thanks,
Henrik