Heater only blows cold air.
If i turn the fan off and leave it for a few minutes, then start the fan up again... warm air blows out for a short time, then goes cold. This can be repeated.
Heater control valve?
Thanks,
Details: T reg 1.25 engine, coolant level is fine.
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The solinoid on the heater control valve seems to either be stuck or open if its faulty not variable. For this reason I would say the fault is more likely to be the heater control panal, e.lg the bet on the dasbhoard where the heater controls are. This sends the signal the heater control valve. I could be completly wrong of course as I am not a mechanic, I have just inidrectly owned 3 fiestas in the past two years so I know their faults all too well.
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May as well change the valve as a first port of call. It's cheap (£25 or so on Ebay) and pretty easy to do, and is a ridiculously common problem on the Fiesta and Ka.
If not, change the panel as Rattle suggests. A breakers is probably your best bet for this.
Unfortunately, testing isn't as simple as checking for voltage at the valve, as the system uses a series of control pulses to operate the valve. It's a ridiculously over-complex solution to a simple problem, and like most over-complex solutions, is unreliable and unfit for purpose. Ask anyone who's owned a Fiesta for a couple of years and they'll probably have had heater problems.
Valve first, in any case.
Cheers
DP
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I should think what is happening is the valve is stuck open part way and is allowing hot coolant into the heater matrix at a low rate - enough to saturate it after a while but not to sustain a full warm flow. A bit like turning the fan on after the engine's been switched off. IIRC there is a by-pass hole in the valve itself, so you may be just be feeling the affects of that.
Yes, replace the valve with a geniune one.
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Thanks for the replies.
I will try a new valve.
If it was a faulty panel, would i get any hot air at all?
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If it was a faulty panel would i get any hot air at all?
IIRC you would get hot air all the time.
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Aha, thats what im not getting.
I get some hot air then a whole lot of nice cold air! (lovely when on the M1 in the middle of the night!!)
Is there any way of checking if the valve is the issue? Or is it a case of replace and hope for the best?
Edited by festalx on 02/01/2009 at 19:06
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Is there any way of checking if the valve is the issue? Or is it a case of replace and hope for the best?
The valve is around £30 from a Ford dealer.
The control panel is over £100.
Unless you have the right equipment (an oscilloscope and a methodology of how to test the system, which I don't have) then you'll have to take it to a competent* auto-electrician who would charge you an hour's labour just for diagnosis, £35+. You'll then spend money correcting the problem.
* Difficult to find unless you know a good one - he might just wriggle his finger in the air and say "control valve!" and still charge you for diagnosis.
Edited by mfarrow on 02/01/2009 at 20:06
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I had a spare a heater control panal but I sold it for a tenner as I knew I would never get round to fitting on my dads as it looks like a hard job. Since his new heater control valve it only blows hot air, it used to blow cold air. I was verycareful to make sure the control valve was not one of the faulty batches too and it was from Ford, cost £45 retail.
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it will be the control panel inside car not heater control valve.common fault.
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I have been having the same problem on a 1996 fiesta I today swapped the valve under the bonnet which did not resolve the issue. I then went onto do a complete flush of the radiator and went as far as leaving the hose in there a total of twenty minutes to flush it right out and refilled. The thermostat seems to work as when I leave the car running stationery for twenty minutes it does heat up and the radiator fan does work as the fan does cut in. I wonder if any one has any ideas
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Apologies for the lateness of the reply to this thread but to Willow and Mikey, the latest contributors before me, if you struggled to replace the heater valve in vain, i sympathise. You also flushed the radiator to no avail, I hear. I can only imagine that the control panel inside the car is faulty, which is more costly to replace, I believe, as I have gleaned from this and other threads in this forum's subject. I hope you got the problem sorted out without too much expense. Scrap merchants have better deals than the manufacturer I hear. Good luck!
However, I would like to thank all the contributors in this thread because I am a complete amateur and I would never have bothered to tackle such a relatively simple car maintenance task without reading the thorough questions from individuals with the same problem and the simple and well-structured replies from the amazing and persistent experienced members of this site.
I am very grateful.
You have saved me a fortune.
With confidence, I bought a "buy it now" heater valve from Ebay for £17 quid plus £3 postage which was posted the next day. I had checked the description of the heater control valve and its location in the Fiesta engine compartment from a previous member so I was pretty sure i was ordering the right thing.
It arrived this morning!
It was a struggle, bending over the fiesta engine compartment. I was also grunting often and loudly while using cheap long nose pliers to loosen the clips which collared the 4 pipes to the old heater valve. Passers-by looked on in awe at my blue jeaned ass, humping my wife's fiesta in its face. There were many expletives to syncopate with this audible rhythm, from neighbors as well as me. However, after 50 mins, I had the new valve in place. I switched on the engine and within 3 mins, hot air was embracing my cold and numb appendages.
My wife was very proud. As was I.
Many thanks. I sometimes have to use the Fiesta on cold mornings. Now I can have peace of mind that the windscreen will clear without having to be wiped a lot and not turning up at work late with icicles for fingers.
Regards
Amoss
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