HI,

I've had no heating for ages now and having had this problem before on another fiesta I thought it'd just be the HCV!

Now I don't really know much but I was told if I bypassed the HCV using copper pipes I'd be able to tell if it's the hcv thats faulty. Anyway I did this and the heater still doesn't get warm! Am I right in thinking if it was the hcv the heater would now be constantly hot with the copper pipes?

If I rev the engine some warm air comes through but when I stop revving it goes cold again!

Any ideas? Should I chewck for voltage anywhere?

Cheers

Ok I think I've narrowed it down to the heater matrix. I took it out yesterday and swilled through with hot water and put it back in and there is a tiny bit of heat now so there must be a blockage in it. I was going to take it back out and leave some coolant flush in it but the guy in the shop said it'd probably do nothing because it'd need to be hot and constantly flowing which obviously I can't do if the matrix is out. I don't think it'd be any good doing a whole system flush as the blockage is pinpointed to the matrix!

Is there anything out there that I could just put in the matrix that would help unblocking it?

It's strange cus when I put the hose on the matrix, water seemed to run freely out of the other pipe so I thought I'd ridded it of the blockage!

Cheers

Ok I think I've narrowed it down to the heater matrix. I took it out yesterday and swilled through with hot water and put it back in and there is a tiny bit of heat now so there must be a blockage in it. I was going to take it back out and leave some coolant flush in it but the guy in the shop said it'd probably do nothing because it'd need to be hot and constantly flowing which obviously I can't do if the matrix is out. I don't think it'd be any good doing a whole system flush as the blockage is pinpointed to the matrix!

Is there anything out there that I could just put in the matrix that would help unblocking it?

It's strange cus when I put the hose on the matrix, water seemed to run freely out of the other pipe so I thought I'd ridded it of the blockage!

Cheers

thats a weird one, maybe some compressed air would help shift whatever is stuck in it. I would be tempted to do a full system flush becuase there may well be contaminants left within that will just clog the matrix again