Morning everyone, if anyone can help with this I'd be over the moon!!! after a timing belt service my heaters started to lose heat but got warm again when driving faster, garage said it sounded like an air block so they did an engine flush and no difference, infact it got worse!! they then changed the HCV and again heaters stayed cold so they bypassed that by using two small lengths of pipe to give me constant heat, I've not got constant heat!!!! Lol, to add to this the two left front heaters are like warm and the right two are cold, oh forgot to mention they fitted a new heater matrix aswell, there's now a drip coming from the water pump area too!!!! And ideas on why all four heaters arnt getting and staying hot???? Previous to this I owned a 51 plate courier van and it was brilliant, just can't figure out why the heaters are like this, thanks everyone, it's a 51 plate tddi without ac, looks cool but really really frustrating without the heaters!!

Thermostat stuck open

what's the temperature gauge say?  if the temp gauge is normal (eg. like half way) and you still can't get heat then it won't be the thermostat.

is the coolant level ok? very low coolant level will mean the heater matrix will be starved of water and just get air (air is no good at conducting heat from the engine to the heater matrix)

Thanks for the replys guys, this model doesn't have a temp gauge!! Coolant level is between min and max, when I go under the bonnet and feel the two heater matrix pipes the short one is cold, I pressed all pipes and the heaters worked better for about an hour then same old like warm and cold!!! Has anyone else had this??

Not had one of the model fiesta myself. I am wondering if there is an air lock in there, but I can't tell you how to sort it not knowing that car type

It does sound like a sticky or lazy thermostat. Your other issue may not have been the HCV itself but the controller to it which is on the reverse side of the heater dial. You can test if this is working by putting a voltmeter on the connections to the HCV with the ignition on and the voltage should go up and down as you turn the heater knob.

just got car back from garage again today, the water pump was leaking so had that replaced and asked the garage if they would bypass the oil cooler too, no more leak and heaters seem alot warmer, not massively hot but a big improvement, the garage think it maybe an issue with the blender door but for now its stopping as it is, just thought id put a post on incase anyone is stuck with this issue, happy fezzey driving peeps !!!