Hi 2001 3.0 se not heat in cabin at all aircon ice cold fan works fine .Suspected heater valve but all pipes goig to and from get hot the three metal pipes that run up to the top bulkhead and go towards the inside the car all hot they then join to rubber hoses that enter the car one is stone cold any ideas?

 

Hi there - I am having the same issue with my 2001 XJ8. Ice cold A/C, no heat. Driving me nuts as well. Yesterday, I replaced the auxiliary heater pump thinking it might be the issue (generally the nr 1 defect) but in my case it was not the issue (turned out my pump was working). My next guess is the heater valve as well - but I am planning to put up a thread in the X308 section just in case. There's also another (non-return) valve at the entry of the pump, but I don't think this one is the problem. I will keep an eye on this thread just in case someone comes up with ideas, and I will share with you what I find out on my end as well. Lucky here in NC that weather is still decent, but we will soon get some frost in the AM and will need to defrost !!

 

I have posted this before if you are interested but on my 2005 STR after I replaced my DCCV and the AUX pump I followed Brutal's suggestion and unhooked all three heater hoses and flushed and then reversed flushed just the heater core. I saw nothing come out and it was unrestricted.

But afterwards I had heat!!

Cheap to do and not to hard.

But have you changed the DCCV or checked if it's leaking? They often start seeping long before you see symptoms.
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Great advice Kevin. Reverse flush the hoses guys.

 

my s has the same problem. 2 Hot pipes to the bulkhead then cold on the 19 mm return but hot on the 19 mm side entry pipe return. Water pump works ok. Did the flush work for the others. I thought there is either an air block in Heater or a bypass valve next the heater core controlled by sensors etc. Would a flush fix an air lock. My heater works ok 2 hours a month so I think its a control tap issue caused by wires loose or sensors. Is there a diagram of this part of the heater system? I remember the days of a simple tap on off......Paul

 

Check he CCM - could be toast. Also, check out the servo motor that controls air flow between the evaporator/heater core - could possibly be malfunctioning.

 

Sorry I didn`t get back to you all on this my tech replaced the heater control valve (second hand from euro jags £60) took him about an hour and a half to fit it (£60)
all is well red hot or ice cold as you wish!

 

Is that the heater control valve behind radiator or under dash

 

Just to clear my head, tooo much work, getting in way of Jag care.

You had hot pipes to and from the core, as do I, right????.

Your mechanic replaced the heater tap (DCCV) alongside the radiator, RH side, and now all is sweet????.

AS you may have read, mine (3ltr), so NO extra pump, has HOT pipes to the firewall, all 3, and NO heat inside the cabin, so spouse is not happy in 4c temps. Worked fine a few months ago.

The taps here are about $300, so I really would like to make sure before forking out that sort of money. The DCCV on ours is not damp externally, so maybe an internal leak?.

Advance thank for any info you can give.

 

There isn't one under the dash is there?

Simplest is to follow the
jaguar climate control
site or the many threads on here.

 

Yes i meant the servo control under dash. My Dccv seems to work ok so something else is telling water not to flow through the core. Is there a water tap under dash or do I look for air lock if servo ok..Paul

 

Follow that site I gave.
Also, get JTIS and read...