The heater in my 1996 Ford Fiester is blowing out cold air only?

Ford Fiester heater started blowing out very hot air for a few days .could not turn down (hotest day of the year aswell) but now only blows out cold air (getting colder in the mornings aswell;arriving out work frozen).I thought that it could be somthing to do with thermostat.if so how can fix it please ?
A Forrest-Hay, November 2006


done
its not thermostat it is a silly electric valve under the bonnet where the two hoses go in to bulk head it has a couple of wires to it ,not hard to change but not cheap .why ford wanted to mix a electric valve with water i will never understand .you could try unpluging the wires sometimes gives you heat other wise a new valve is required.

weirzy, November 2006
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