Mk7 Heater permanently on

[GrantD]

Hi everyone

Tried to search for this but didn't have much luck.

So, I thought that the a/c was bust on my 2011 Fiesta. Took it to be re-gassed, and it made no difference. All I got was hot air coming through the vents. Tried again in an attempt to reduce the amount of refrigerant, thinking that perhaps there was too much pressure, but no luck. 

Took it to a garage for a proper diagnostic and the guys came back telling me that the a/c works, but the problem is that the heater is permanently on. So anytime I turn the fan on - a/c or not, I just get hot air coming through. If I do turn the a/c on, I get an intermittent, rapid clicking sound coming from behind the unit. Similar to this... 

 

It used to only happen at high temperatures, now it happens pretty much all the time.

Before I head to Ford for some expensive labour and investigations, does anyone have any ideas...? I thought maybe I could just disconnect the heater hose for the summer 🙂 I can put up with the clicking, but I would rather do so being cooler 🙂 

Any ideas welcome!

 

[Luke4efc]

Is the heater control valve not stuck open? The clicking sounds like the actuator struggling to close the valve. You could bridge the inlet and outlet then just blank off the heater matrix to stop crap getting inside for the summer. Just means bleeding the system each time.

[GrantD]

Yeah that was my thinking too - about the sound of the actuator. 

Is that bridge easy enough to do myself? 

 

[Luke4efc]

As long as you can undo the connection in the inlet and outlet of the pipes that go inside the cabin then yes. You'd also need a small piece hose with an internal diameter the same as the outer diameter of the existing hose so that you can jubilee clip them on.

Personally I'd look at trying to actually fix the fault rather than bodging it. You would probably find fixing it also takes less time. If it's not the heater control valve then it could be the blend door being stuck open to hot side. I'm not sure how big of a job that is

[GrantD]

Thanks guys. Yeah, I’d also prefer to fix the actual issue. 

 

I’ve taken the car to a couple of other garages to check it out. Unfortunately, the response is that they simply don’t know what the problem is. 

 

Reluctant to take it to Ford, but seems that’s the becoming the only way to fix it for sure. Probably the quickest too