Good Evening
I have a 2012 4.4 tdv8 Westminster
I don't seem to be able to get the FBH to heat the cabin when switched on either with remote fob or through the touch screen unfortunately I don't have access to diagnostics at present, but I have been told by my local indy that services it that the FBH should only assist in warming the engine, and not warm the cabin.
But everywhere I read say it should heat the cabin up and just wondered if anybody could clarify this, and have any suggestions as to why its not doing so. It does fire up when cold but no heat into the cabin.

Regards
Dave.

The FBH warms the cabin, not the engine!

I also have a 2012 4.4 TDV8 Westie, although I don't have the remote. I used to have a remote with my previous 3.6 Vogue.

Have you tried setting the Timed Climate from the screen and then switching the car off and locking the doors? The timed climate won't operate if you are sitting in there watching the clock! The older I get, the more I realise that people confuse wrinkles for wisdom

I’ll keep looking if it should heat the cabin up, it does fire up when its cold when the engine is running which I’ve been told is to speed up the warm up period, and if I stop it I can smell the diesel fumes, so it does work in a fashion.

Thanks anyway

I have a similar issue, FBH works but doesn't heat the cabin.

Read the codes with IID yesterday:

B12A6-15 (2F) Auxiliary heater water pump - General electrical failure - circuit short to battery or open

It will heat both cabin and engine as it's a spur on the main coolant system but it won't do it immediately and you need to set it off well before you get in the car. Like 1/2 hour before depending on how cold it is. Also AFAIK you need to set the heating dial to higher settings 2012 TDV8 Vogue (L322)

Hi Thanks
I will have to try the heater controls I can't say I've tried that

Regards
Dave

No need to play with heating dials, not in my MY11

FBH will heat engine or cabin depending on outside temp

Cabin gets heat at <15 degrees
In very cold conditions, not specified on p61 of the handbook for MY11, FBH warms the engine to aid starting.
Not sure what that very cold limit is. I think <-20 degrees where FBH focus is on the engine.

JLR initially kept the cycle time for the FBH at 30 minutes when they rolled out the AGM batteries on the MY11s
Dealers changed this to 17 minutes to avoid the FBH cycle leaving MY11 owners with warm cabins but stranded with flat batteries.

If you are on a 17 minute cycle time with the MY12s, you may sometimes think the cabin has not been heated on a really cold day when the FBH has been operating and you would be right
The engine will have been warmed though.

You can reset the cycle time with the IID tool

So set at either 17 or whatever cycle time minutes you have in advance of when you want to drive off

Easy to tell if FBH is operating on a cold day
Go listen a few minutes after it has started\
You should be able to hear the fuel pump ticking

One final thought
Sometimes my battery (about 2 years old) tells the car that it is nearing the point of being unable to start the car, so FBH is shut down early
Also low fuel can be a reason for FBH not running properly

Last edited by Rambles on 21st Feb 2022 7:28pm. Edited 1 time in total

So that's what the ticking noise is......
Never used mine to pre heat the car before startup as not had a new battery that long but it definitely speeds getting the engine up to temps on cold mornings. 2012 TDV8 Vogue (L322)

Hi, you could try and pull the fuse for the FBH and it should reset itself, if there are a number of failed attempts at running the FBH it can lock itself out. Pulling the fuse and reinserting can usually cure the issue of it not running. I’m sure if the outside temp is 16 degrees or lower is will heat the cabin but need to run for at least 20 minutes on diesel, if the temp is lower than 6 degrees it warms the engine to assist cold starting.

JMC wrote:

The FBH warms the cabin, not the engine!!

Hi,

other way around

the FBH, as already said, is to help get the engine up to temp quicker, a by product is it can be used to warm the inside of the car as well as it is heating the coolant system.

OP. try setting your TC for half hour before you want it, all locked up and go out early to listen what is happening, you should hear the FBH running like a little jet engine then unlock and see if its warmed inside as well

Just a thought does it have the change over valve and is it working.

RiverBlanche wrote:

other way around

Happy to be corrected, but after thirteen years of using a Range Rover FBH in a cold climate, here's my understanding:

If the FBH is used from the remote (or from the timed climate setting), the system heats the closed loop system of the cabin to warm the cabin only. When the engine is started, the valve is opened and the warm water then helps to heat the engine.

The FBH works independently of the cabin heater function and will run indpendently to assist warming the engine when ambient temps are below 5deg, but this has nothing to do with cabin heating.

With the car parked-up and locked, I persist that the FBH is for cabin heating only. The older I get, the more I realise that people confuse wrinkles for wisdom

^ this is my understanding and also my experience with both of the Range Rovers I have had with FBH's. 2017 4.4 SDV8 Autobiography
2012 4.4 TDV8 Westminster - Gone, but not forgotten

JMC wrote:

RiverBlanche wrote:

other way around

Happy to be corrected, but after thirteen years of using a Range Rover FBH in a cold climate, here's my understanding:

If the FBH is used from the remote (or from the timed climate setting), the system heats the closed loop system of the cabin to warm the cabin only. When the engine is started, the valve is opened and the warm water then helps to heat the engine.

The FBH works independently of the cabin heater function and will run indpendently to assist warming the engine when ambient temps are below 5deg, but this has nothing to do with cabin heating.

With the car parked-up and locked, I persist that the FBH is for cabin heating only.

I can confirm the same, unfortunately, as I want it to work the other way around and preheat the engine

I had always thought…
Because of the comment in the MY11 handbook….last para on p61
That “in very cold conditions”, the FBH is used to “warm the engine and aid starting….”

To aid starting, the FBH has to operate before you start the engine.
So I looked in the workshop manual.

As folks say, there is a changeover valve which can isolate the engine coolant circuit from the heating coolant circuit for cabin heat.
At 15 degrees and below
BUT
In very cold conditions,
-20 degrees
The changeover valve is not energised and the blower is not activated. Heated coolant is circulated around the engine and heater cores to heat the engine and aid starting.

In the workshop manual, go to climate, auxiliary heating, locations….for a full description.

You can find it in the section “programmed parked heating / ventilation”