Quote:

The changeover valve isolates the heater coolant circuit from the engine coolant circuit.

With yours being a v8 petrol have you even got the FBH ?

i thought it did both...loads of info in the wiki..

I have a Defender with the same heater in but no diverter valve so it heats both the engine and vehicle interior so there is nothing in the heater to stop you removing or disabling the diverter. I think in the handbook it says something about heating the engine rather than the interior if it is below -20 so I wonder if that temp cold be changed. 2010 3.6TDV8 Stornoway Grey/ Black interior - gone
2005 4.4V8 (M62) Bonatti Grey/ Parchment interior - gone
1998 4.6HSE Blue/ Cream interior (can't remember exact colours) - gone
1977 White - gone (should have kept)

As I read it, the FBH operates in parked heating mode to only heat the interior, thus the changover valve sets itself so the coolant goes to the heater matrix only, circulated via a pump in the FBH. Thus not heating the engine.

The FBH will start on engine start to assist in reducing the warm up time, circulating through the engine, and I assume the heater. This helps in reducing emissions.

The changeover valve needs to be energised to isolate the heater from the engine. Perhaps if you remove the supply to the valve, it may stay in the postion necesssary to join the two circuits, then you can fire it up as a park heater and you may find it gives a bit of heat to the engine, prior to starting.

At least that way you will only (famous last words) have to reconnect the valve if it's not satisfactory or gives a fault. Cheers
Richard

(there are no such things as an ordinary FullFat, an ordinary cat or too many tools)
2011 TDV8 Vogue Santorini Black
Gap IIDBT

kds2 wrote:

With yours being a v8 petrol have you even got the FBH ?

Afaik

Park heat - just interior
Cold start - engine

If it can be Removed it will mean that when you run the Park heater all the heat generated will sink into the engine and the cabin wouldn’t warm much even if there was coolant circulating. There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
KIA E-Niro 4+
2021 Discovery 5 D300 MHEV commercial

D3;s without park heat - FBH heats the coolant only and quickly. I use this every day and the engine temp is displayed on dash at start up so happy engine starts every time and immediate warm air shortly after start up.

IIRC, diesels need the FBH as it takes so long to get warm so are fitted as standard (although many don’t have park heat option)

Petrol Engines warm quickly hence don’t need the FBH so where fitted as an option, when the FBH is switched on (pre-heatingthe Cabin for instance), the coolant is only directed to the heater matrix. This is then switched to full circuit (including the engine) afterwards. (Think I got that right?)

@OP - lovely car btw. How many miles/km?

Totally awesome car. I would like to find these same rims for the winter tyres too, but unfortunately these are quite scarce here in Finland.
So far 325 000 km.

I recall reading somewhere that when the temperature drops below a certain value (can't recall what exactly, I'm afraid, but it was quite cold), that the system changes focus and warms the engine coolant instead of the heater circuit. 2010 4.4 TDV8 Vogue SE