Weird heating issue - advice pls

[SilverGTi_6]

Hey all,

Picked up my (second) RCZ recently. Loving it, other than one strange issue.

(Ive done extensive searching, but haven’t managed to come up with anything definitive)

Issue

Basically, really hot heat is pumping into the cabin, no matter what the temp is set on (even on low). Weirdly, seems to be predominantly on the drivers side, and most noticeable from the foot vents. With the AC on, it seems to be ok (or at least not as hot).

My guesses are along these lines, but this is just based on lots of searching:

- a heater flap may be stuck or something that is directing heat to driver side?
- some kind of servo that controls the flap may be stuffed?
- the heater matrix could be blocked? (Coolant was lowish when purchased, but hasn’t dropped noticably since)
- unlikely, but the heater control panel is faulty? (It did weirdly go blank the other day, but came back when I pressed a button)

Your expert advice / guidance would be very much appreciated as my excellent mechanic is currently out of town!

Just wanting to make sure it’s nothing serious as we have a few long distance road trips coming up.

Thanks
Ben

 

[neilgsxr69]

There are heater tube blanking ends that are under the centre console on each side of the footwell they do come off and blow heat in the area your talking about and do cause heat issues with the media systems it’s from the 308 that has the air scarf installed that the RCZ doesn’t use but I wouldn’t have thought they would still blow hot if you had turned the heat down

 

[SilverGTi_6]

Thanks heaps mate. I have those blanking ends on my list to check as I know the previous owner has recently replaced the Media System. Hoping I can get to them with minimal panel removal.

That said, heat is definitely coming out of the vents, and not only the footwell vent (face level also). As you say, this shouldn't happen if the heat is down (especially on low).

I guess worst case (for our upcoming long trips) is the heater matrix being the cause, but I can't seem to find many examples where the matrix is failing and it's really HOT air coming out of the vents. Most I could find seem to be the opposite (ie next to no heating).

 

[SilverGTi_6]

Does anyone know about heater matrix failure symptoms? Is blowing very hot air on one side definitely something that could negate this as an option?

 

[Pedro]

Air Con maybe at fault & an issue like this can be the Gas is the cause ?

 

[SilverGTi_6]

Thanks mate, the AC seems to blow very cold, so don't think there's an issue with it. I'm also aware the previous owner replaced the compressor a year or two ago.

I did a bit more investigating this morning:

- Passenger side: Everything seems to be working perfectly - ie it's freezing cold with AC on (out all LHS vents), it's hot when heater is on, there's no hot air when temp is low.
- Drivers side: blows hot air all the time - With AC on, it's less hot (as it's mixing with the cool air), but definitely hotter than the passenger side. With AC off, it blows hot air all the time, even with temp set to low.

I'm leaning towards a heater flap / actuator / motor that is not functional and therefore always allowing hot air to come out the drivers side.

Just to be safe, I still really want to make sure the heater matrix can be negated. I'm just not certain how to do this.

 

[Pedro]

Yeah you could be right amazingly these flaps just fall to bits !

 

[SilverGTi_6]

Thanks mate, hoping it’s just the little motor on the side, but guess we’ll see.

Seems to be losing a slight amount of coolant, but leaning towards this being nothing to do with the heater matrix.

 

[littlepippin]

There must be a sequence to reset the unit. My old CLK would go through a flap reset sequence if you pressed a couple of the buttons together at the same time.

Appeal to Peugeots garage for a bit of freebie info - the unit is very common!

 

[SilverGTi_6]

I had a bit more of a look yesterday, heater matrix seems fine (both pipes hot, no signs of major leak) and both heater flap actuators (passenger and driver side) seem to be operating when heat is adjusted.

I haven't found anything online about a flap reset with extensive searching, but that would be an ideal Outcome.

 

[RZC2010]

mine doing a similar thing. but ive noticed if i go hot to cold to hot to cold a few times, mine will eventually change. so i think its the flaps or the motor.