C4 GP 2017 heater not working

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Alexsjob
Posts: 9
Joined: 05 Dec 2023, 18:07

C4 GP 2017 heater not working

Post by Alexsjob »

Hi all,

The heater in our 2017 C4 GP just stopped working. The fans and dual zones work fine, when we up the temp to 'hi' it blows with full force, but no heat.

Is this a common problem with an established fix, or do any of you have some tips for troubleshooting before handing it over to the mechanic?

Thanks
Alex,
Sweden
RichardW
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Joined: 07 Aug 2002, 17:12
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Re: C4 GP 2017 heater not working

Post by RichardW »

First check is the coolant level - heater is usually first to go if it's low.
Richard W
Alexsjob
Posts: 9
Joined: 05 Dec 2023, 18:07

Re: C4 GP 2017 heater not working

Post by Alexsjob »

I checked and the level seems fine. Slightly above minimum.
owl
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Joined: 07 Oct 2025, 19:26
x 15

Re: C4 GP 2017 heater not working

Post by owl »

It seems known chronic heater blend flap issue. Try manually set for heating. Flap motor is located (for left hand drive, I dont know for rhd) in the driver’s footwell, upside of accelarator pedal or behind the glovebox on the passenger side.
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mickthemaverick
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Re: C4 GP 2017 heater not working

Post by mickthemaverick »

Alexsjob wrote: 01 Nov 2026, 11:21 I checked and the level seems fine. Slightly above minimum.
I would suggest that slightly above minimum is not fine. Given that below minimum could result in the engine overheating, hence the scale, then just above minimum suggests adequate for engine cooling but nothing else. Top it up to max and see how it performs then! :)
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I used to ride on two wheels, but now I need all four!
Alexsjob
Posts: 9
Joined: 05 Dec 2023, 18:07

Re: C4 GP 2017 heater not working

Post by Alexsjob »

Agree. Will do!
Alexsjob
Posts: 9
Joined: 05 Dec 2023, 18:07

Re: C4 GP 2017 heater not working

Post by Alexsjob »

owl wrote: 01 Nov 2026, 11:34 It seems known chronic heater blend flap issue. Try manually set for heating. Flap motor is located (for left hand drive, I dont know for rhd) in the driver’s footwell, upside of accelarator pedal or behind the glovebox on the passenger side.
Sorry, but what do you suggest I do with it once located? :)
owl
Posts: 97
Joined: 07 Oct 2025, 19:26
x 15

Re: C4 GP 2017 heater not working

Post by owl »

Alexsjob wrote: 01 Nov 2026, 13:59
owl wrote: 01 Nov 2026, 11:34 It seems known chronic heater blend flap issue. Try manually set for heating. Flap motor is located (for left hand drive, I dont know for rhd) in the driver’s footwell, upside of accelarator pedal or behind the glovebox on the passenger side.
Sorry, but what do you suggest I do with it once located? :)
Take off the electric servo/actuator motor and manually rotate the stub or flap axle with your fingers or a small tool to set it to hot or cold. It is going to be temporary solution. In that case you will not able to use cold air. It means if you have auto A/C set on 21C for example it will be hell hot inside 26C :)
As I said temporary solution if it is actuator flap.
Alexsjob
Posts: 9
Joined: 05 Dec 2023, 18:07

Re: C4 GP 2017 heater not working

Post by Alexsjob »

owl wrote: 01 Nov 2026, 15:05
Alexsjob wrote: 01 Nov 2026, 13:59
owl wrote: 01 Nov 2026, 11:34 It seems known chronic heater blend flap issue. Try manually set for heating. Flap motor is located (for left hand drive, I dont know for rhd) in the driver’s footwell, upside of accelarator pedal or behind the glovebox on the passenger side.
Sorry, but what do you suggest I do with it once located? :)
Take off the electric servo/actuator motor and manually rotate the stub or flap axle with your fingers or a small tool to set it to hot or cold. It is going to be temporary solution. In that case you will not able to use cold air. It means if you have auto A/C set on 21C for example it will be hell hot inside 26C :)
As I said temporary solution if it is actuator flap.
Got it. Thanks. :)