Hi, I was wondering if someone could point me in the right direction as to what the issue is with my Heater. 

The heater/blower blows cold air regardless of what temperature the heat is set to until the power is set to number 4 where you can hear a 'pop' type of sound and then will blow out red hot air. Then the only way to get cold air back is to completely turn off the blower and wait for another popping type of sound and the heater will then blow out cold air. Does anyone have any idea as to what this issue is as it's getting pretty frustrating trying to equalise red hot air with cold. 

Thanks

4 hours ago, JackCrossland said:

The heater/blower blows cold air regardless of what temperature the heat is set to until the power is set to number 4 where you can hear a 'pop' type of sound and then will blow out red hot air. Then the only way to get cold air back is to completely turn off the blower and wait for another popping type of sound and the heater will then blow out cold air.

It sounds to me like the flap vane inside the heater unit that diverts the air through the heater matrix, is sticking. And it needs the additional aid of the max air flow to make it unstick & flip over to the other state.

Another test would be to set the blower to 4 with the heater in the cold position, then slowly (or quickly if that fails) turn the temperature setting up until it pops to the hot position. I am rather assuming it is manual, not climate, control.

If it proves to be the diverter vane, it is a bit of a pig, probably needs the dash out to get at the heater.

I can not think of electrical faults that match those symptoms, even if it is climate control. But it would be worth taking the heater control unit out to check the linkage from it to the heater. That is quite easy on the Focus, hopefully also on the Fiesta.

15 hours ago, Tdci-Peter said:

It sounds to me like the flap vane inside the heater unit that diverts the air through the heater matrix, is sticking. And it needs the additional aid of the max air flow to make it unstick & flip over to the other state.

Another test would be to set the blower to 4 with the heater in the cold position, then slowly (or quickly if that fails) turn the temperature setting up until it pops to the hot position. I am rather assuming it is manual, not climate, control.

If it proves to be the diverter vane, it is a bit of a pig, probably needs the dash out to get at the heater.

I can not think of electrical faults that match those symptoms, even if it is climate control. But it would be worth taking the heater control unit out to check the linkage from it to the heater. That is quite easy on the Focus, hopefully also on the Fiesta.

Brilliant, thank you and yeah once the power is set to 4 it will blow really warm air out pretty much instantaneous regardless of what heat temperature it is set to and yeah it is manual, I'll have a look into it and see if I'd be able to sort it. Thanks for the response, it's very helpful. 

44 minutes ago, JackCrossland said:

once the power is set to 4 it will blow really warm air out pretty much instantaneous regardless of what heat temperature it is set to

From what you say there, it seems the temperature control actually has no effect, and it is just the blower setting that is opening the diverter to provide heat. I have never seen inside a fiesta heater (!), but it sounds like the linkage from the temperature control to the flap is broken, and the flap is just moving by air pressure from the blower.

With luck, the break could be outside the heater, in a more accessible place. Just hope Murphy's law fails for once!

Hi I’m having the  exact same problem!  Popping sound,  that’s only when I set the blower to maximum I have the climate control model did you manage to resolve the issue? 

Hello, did any of you manage to solve the problem? It seems like I have the same or very similar problem. When I push the button to redirect the air to the front vents, there is a pause (like a second), then a pop a then the air starts blowing out of the front vents.

Any help would be much appreciated.

 Hello who ever is reading!

I have just had this same issue, looks like the fix is on the link below:-

 

 

Keeps safe

😄

Plastic deterioration after 10 years just like rubber pipes.