clevokid

Any suggestions welcome on this problem. Not getting much heat out of my heater, have flushed system myself then put in chemicals to clean it. Took it to radiator shop and had it powerflushed...still no good. Replaced electric thermostat behind glovebox and got a small improvement but still not hot. Has had waterpump,thermostat and all hoses etc replaced and if hoses disconnected seems to have plenty of flow through the heater core with a garden hose into one side. Got me stuffed anyone had anything like this? cheers

roofi

Check vacuum lines to the flaps that let air flow the heater elelment and heater tap. Also blockage in the heater tap

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XF PV EEC-IV
Subaru RX Turbo
Van Diemen RF86
Softride Powerwing

yeah right

Heater tap? What and where is this? My XF Ghia has the same problem - no warm air - well - next to none anyway - a very minor detectable change in temperature. The valve in the engine bay is gone, so it should be hot all the time! Is there another valve between the dash & the firewall (behind the glovebox). The vacuum supply to the controls is good and the threaded rod connected to the black cam/disc moves when the temperature slider is adjusted - but I don't know what it connects to.

XWish Ute

Should be under the bonnet in line with one of the hoses. Has a silvery or gold (depending on how old it is!) metal vacuum canister (about 1 inch round) on the side to operate it. Can pull the heater valve out and attach a length of hose to the vacuum port. Suck on the hose and you should see the flap inside move if it is working. These things often fail. Also check that the hose has vacuum applied to it if the valve seems ok.

XWish Ute

Sorry - should have read in more detail! The heater tap is a small vacuum valve operated by a cam on the heater box, but if you have removed the the one in the engine bay it would make no difference.

so with this in mind, since there is plenty of coolant flow, I reckon the heater blend flap in the heater box is jammed closed. This is a vacuum operated flap, so if you have disconnected or leaky vacuum hoses/fittings, that would be your problem! No airflow through the core = no heat.

Hope this helps!

yeah right

The only disconnected vacuum line is the one that should be connected to that isolator in the engine bay - but that line has been capped so should make no difference.

The flap certainly moves through it's full range of motion (if it's the one I'm thinking of) - you can see the threaded rod actuate it through it's full range of motion.

I'm leaning towards a partially blocked heater core. It's due for a coolant change anyway so I might just do that this weekend and give it a reverse blasting through the core at the same time.