I have a Ford Ka 'W' Reg. Had a problem with it over the summer where the heating controls would only blow out hot air regardless of the temperature setting, so I changed the heater control valve in the bulk head and the problem was solved.

Now however, I cant get hot air, only cold! Any idea what the problem could be?

A smaller separate problem, when I turn the rear wiper on, it doesn't work. But if left on, after 10 minutes or so it will just start working! The rear demister doesn't work either. (should I just scrap the car

Thank you!

With regards the heating, check the electrical connection to the HCV is clean and properly pushed home. If not it could be the Heater Control panel has gone behind the heater control knob. I would try an electrical tester on the lead to the HCV to check there is a voltage change when you adjust between hot and cold.

If that doesnt work it could be a duff HCV (they have been known to fail even when new). Or it could be the Thermostat is stuck open. Does the temperature get hotter if the car is running whilst stationery for a period of time?

The other problems sound like the contacts in the boot need checking. Make sure they are clean and there isnt anything obstructing these.

Good luck.

Hi, the temperature of the engine (not the cabin) does get hotter if the engine is running for a period of time. I did change the thermostat a few months ago as the car was overheating. I'll check the control panel and let you know how I get on, thank you.

[quote name='Sanjit' timestamp='1319572311' post='149968']
I have a Ford Ka 'W' Reg. Had a problem with it over the summer where the heating controls would only blow out hot air regardless of the temperature setting, so I changed the heater control valve in the bulk head and the problem was solved.

Now however, I cant get hot air, only cold! Any idea what the problem could be?

A smaller separate problem, when I turn the rear wiper on, it doesn't work. But if left on, after 10 minutes or so it will just start working! The rear demister doesn't work either. (should I just scrap the car

Thank you!
[/quote]

I had the opposite problem with a fiesta. Blowing only cold air, changed the control valve from ford dealer, then only blew hot air. Changed control panel and made no difference. Bought another control valve and that cured the problem. The 1st part i bought was faulty! You can check the valve by connecting it directly to the battery terminals. The valve doesn't stay open or closed it pulses constantly to let varying amounts of coolant into the heater matrix.

Ok, changed the heater control valve, topped up the coolant and all was working well. Heat or cold worked fine. But then I could hear a sort of heartbeat type sound coming from where the heater control valve is located and now I only get hot air! Grrrrr!

Any ideas, please!?

[quote name='Sanjit' timestamp='1319814281' post='150327']
Ok, changed the heater control valve, topped up the coolant and all was working well. Heat or cold worked fine. But then I could hear a sort of heartbeat type sound coming from where the heater control valve is located and now I only get hot air! Grrrrr!

Any ideas, please!?
[/quote]
Are you still getting the pulsing sound from it opening and closing, or has that stopped? It adjusts the temperature by opening and closing the valve, unless you have it on cold, where it should just close it fully. If its stopped and you are getting hot air, it is stuck open and may have packed up again.

Well I've tested it again, and the hot and cold seems to be working again, I can still hear that pulsing sound though which I don't remember hearing before. The only thing I can think of is when I removed the old HCV, there was a rubber thing which sat between the HCV and the metal mounting, this disintegrated which I didn't replace. Perhaps there no deadening to the sound now?

Could well be the rubber/foam strip took out some of the noise. At least you know its working.