In this guide i'll show you how to replace the Heater Control Valve on the mk4 and mk5 fiesta
These often fail and leave you with really hot or really cold aor through your blowers.

Tools Needed:

mould grips or similar

Parts Needed:

Heater Control Valve

Heat me


If your car starts to overheat regually or the heater matrix will only blow out cold
or hot air on which ever setting then it is more than likely the HCV.

These are a common problem on the mk5 series.

First of all make sure the car engine is cold - unlike i did
and locate the hcv - its situated near the window motor. (see pics)

It will have a plastic cover on so just remove this to see the valve its self.


Now firstly remove the two metal clips from the two front pipes and remove those two pipes.

- If the engine is not cool these will be full of hot water!

As you pull each pipe off keep it upright to avoid losing water.


If you wish, mark each pipe you take off to remember where it goes when putting them back.

Now take out the two little screws either side of the hcv at the front of the heating
plate/guard so that you can access the two rear pipes and the valve better.

Now access is better, again remove the two metal clips off the two pipes and remove those.

Dont forget to unplug the wire connector off the valve too.


The hcv should now be easy to remove.

My new valve against the old..


Now reverse the steps and put back into place.

When complete check the water levels and replace any lost water.

Now start the engine with the water cap off and check for any air blocks.

As now the engine will be warm, check your heater and check to see that you have warmth and cold air.

Finally go for a drive and double check that this has stopped the overheating.
If this hasnt, ask on the forum for further assistance.

I hope this guide is of use to someone.

Guide Written and © On 25 Dec 2009 by Steve Collett (Steve1127) for

© Andrew Whiteman. On the Net since 2005