Ford Fiesta heater only blowing cold air

[BazzaS]

My son has a 1993 Fiesta 1.1 (HCS engine). Since the weekend the heater has only blown cold air. There was a leak from the water pump gasket which I have renewed and now there is no leak. I thought this might have been the cause - it wasn't.
Now, I've seen a number of references to either a 'heater valve' or an 'electronic valve' but can't find either on my son's Fiesta. Nor, for that matter, can I find a reference to these in the Haynes manual for this car. If it helps all water pipes are either hot or warm - none are cold to the touch.
So can anyone please advise me what the cause might be and what to do next ?
Thanks

 

[redrunner]

dont know if this helps but have you looked for this valve right at the back in the engine bay where the wiper,s and motor are ? i changed one on a fiesta a while back for daughter in law , but it might have been a different model fiesta. hope this helps. r.r.

 

[BazzaS]

Thanks for your speedy response, Redrunner. No I haven't looked for the valve - tell me what it looks like and I'll do so tomorrow.

 

[breezer]

sorry if i am stating the obvious, but i have seen similar on a vauxhall, problem was solved by adding more water to the "radiator bottle" it was below minimum fill line.

also may be an airlock in heater pipe

 

[raceinon69]

check water level is correct ,run car up to temp check all water pipes are hot sounds like air lock or thermostat stuck .

 

[suggs]

Did you put in leak sealer

 

[keyplayer]

Probably as mentioned an airlock. When cold, remove cap from header tank, set heater to max in car and top up coolant and pump top hose with your hand. This should shift any air as long as you have no blockages. And assuming the hot/cold cable is functioning ok. Resistance present in slider? As you have drained coolant what condition was the header tank in? If it was all sludged up this could indicate a system flush required.

 

[BazzaS]

Thanks for all you help/advice. It was indeed an air-lock. After refitting the waterpump and topping up the coolant I had merely put the cap on and left it at that - notwithstanding that the Haynes manual says to run it up to temperature with the cap off to clear air-locks !! I've now done it properly and am like a roast pig !! Whooppeeee.
Regards