Only hot air out of heater!

[nickhalluk]

I've got a mk2 ph2 with climate and have just noticed that no matter what I set the temp to it only throws out hot air.

I've had a search about but cant find a solution.

everything else on the climate control works fine, I can adjust the fan speed and location (window, feet, face etc) and when I press AC you can here it click as it comes on, but the heat always comes out red hot.

where is the valve that adjusts the water flow? this is the only thing i think that could be the problem, it must be sticking open?

anybody got any ideas/suggestions?

Ta, Nick

 

[Josh@Renparts]

its a servo motor that changes the flow of air past the matrix, very labour intensive to have repaired, the part is pretty cheap, might have been 10 hours labour or something silly. Try messing with it with the air speed off, tends to be intermittent for some time until eventually the gears inside won't mesh at all.

 

[SBV116]

At least its not stuck on cold!!

 

[bmh.01]

Could be a fucked temp sensor thinking its cold all the time? Other than that I could only guess its the servo.

 

[bearne1]

Had a very similar problem and found out it was the interior sensor - was missing!

 

[dobbsport]

i had this problem with my 172 ph2.... needed a new heater box and servo motor.... cost £670 from renno..... (servo motor was faulty and damaged plastic teeth on heater box)

 

[nickhalluk]

its a servo motor that changes the flow of air past the matrix, very labour intensive to have repaired, the part is pretty cheap, might have been 10 hours labour or something silly. Try messing with it with the air speed off, tends to be intermittent for some time until eventually the gears inside won't mesh at all.

the temp is adjusted by the water flow to the matrix, not the airflow past it. the air flow is what points the air to the window/feet/face, this is working fine.

At least its not stuck on cold!!

lol, yes, but I'm off to France in it in the summer and then I'll be wishing it was...

Had a very similar problem and found out it was the interior sensor - was missing!

the sensor is definitely there, you can hear it squeaking , also the sensor will only be used when it's set to auto, when I set it to manual and min it still only blows hot.

I might go and get a Haynes Manual should be able to work it out from there...

 

[bmh.01]

No the sensor will be used all the time, although if you set it to minimum and its still blowing hot i'd say its worse things. The only way the sensor will be the problem is if it thinks its -5c or something all the time.

As obviously when you set a temp say 18c on the C/C it looks at the interior cable temperature to decide the hot/cold mix.

 

[Michael172]

Sounds like a clio tbh.

 

[Darren172]

I have the noisy climate control fan. Last night my 172 ph2 has developed the same problem, only hot air is coming out of the vents, no matter what you set it to. Bit skint at moment so hopefully its nothing serious. If you manage to fix it share the knowledge please dude

 

[dr_sybourg]

i got exactly the same problem with mine, i do find though if i put the temp up high and bring it down slowly it sorts itself out, not for long though!

On the last service i asked about it, garage had a look and said the same as JOSHYDEE, £400 + VAT to fix!

 

[Env]

Enjoy the mornings.

 

[TOGUSA]

could it not just be a air con refill.......? somthing simple as that?

 

[nickhalluk]

Well after all the worry about how much it will cost to fix, I got in the car today and its fine...

I can put it up to full heat and then back down to minimum (with the AC turned off) and you can feel the temp change...

Over the weekend I did pull out all the fuses and check them as well as removing the head unit to see if some of the wires had fallen down into the heater units controls and jammed them. I also found a bleed valve on the side of the engine where the heater matrix takes its feed from. I opened this fully it spat a bit of water out, didn't seem to be an air lock.

the only thing I can think it could be is that I had done a 3hr drive on Sunday when I noticed the problem, so the engine would have been very warm and the water pressure inside the pipes would be quite hi.
I know on standard heater matrix (not climate control) the heater knob links directly to a valve on the matrix that adjusts the flow of hot water from the engine to the matrix. Air is passed over this and used to warm the cabin. I would expect that the only difference on a climate control system is the manual knob is replaced by a servo/motor. if the water pressure is hi, this will be harder to move so if the servo is old/on its way out it might not have the power to close the valve.

Does anyone have a Haynes Manual to confirm this prognosis? I need to get my self one.

 

[Josh@Renparts]

yeh your sort of correct in what you say, motor is on its way out though by the sounds. Just adjust it when there is least strain on it and hopefully will last a while.

 

[Darren172]

Mine kind of works now, but once you adjust the temperature up, it will not lower back down. The numbers change, but the temperature doesnt.

 

[nickhalluk]

Got it sorted, joshydee was right, there is a baffle inside the heater matrix that directs the air past the heater element and controls the cabin temp.
Bolted to the right hand side of the heater matrix, in the drivers foot well there is two stepper motors, one controls the direction of the air (feet, windscreen and face) and the other controls the flow past the heater element to adjust the heat of the air entering the cabin.
The motors have a star shaped cog that attaches each of them to the controls on the heater matrix, the only difference between Clio’s with climate control and manual heating are these motors, in the manual systems they are controlled by wires directly from heating control panel below the stereo.
Anyway, where these cogs attach to the matrix, the ends had splayed and hence, if the air blowers were up hi, or you are driving at speed the air flow past the baffle was too much for the cog to move the baffle and caused the cog to just turn damaging the teeth.
I was just going to pack the cog with “hot glue” but managed to fix it by just tightening a cable tie around it, it worked a treat.
If you’re having the same problem try the same as a quick fix, OR if you are on the road when it happens, if you turn you fans off and put the air to re-circulate (to stop any airflow past the baffle) the cog might get enough purchase to move the baffle.
Added some pics so you can see what I did, hope it helps

 

[statik]

How easy was it to access these stepper motors? I've heard in the past that this fix would have involved much of the dash being removed and was a costly procedure. Was this the case?

 

[nickhalluk]

How easy was it to access these stepper motors? I've heard in the past that this fix would have involved much of the dash being removed and was a costly procedure. Was this the case?

No, it was really easy. just removed the centre console (bit with gear stick and cup holders). The gear stick surround just pulls up, pull the back of away from the dash, it is held in with poppers. the front is held in with Velcro. once that's out the way the motors are just in the foot-well. The two motors are attached to a metal plat which is attached by three screws. very straight forward.

If you wanted to do a full repare, .i.e new cog, you would have to take the whole heator matrix out and strip it down, which might be a dash out job, but, it looked possible without taking the whole dash out. I'm sure the haines manual ent on to describe removing the matrix, without taking the dash out.

 

[Josh@Renparts]

glad you got it sorted, i like been right
got the exact same problem on a p38 range rover, a real mission on that.

 

[Wizbit]

No, it was really easy. just removed the centre console (bit with gear stick and cup holders). The gear stick surround just pulls up, pull the back of away from the dash, it is held in with poppers. the front is held in with Velcro. once that's out the way the motors are just in the foot-well. The two motors are attached to a metal plat which is attached by three screws. very straight forward.

Many, many thanks for this info. I have been having the same issue since last year and even bought a new resistor pack to fix it, but that did not cure the problem (Waste of £80+). Your pictures and quick-fix suggestions were spot on and I managed to do exactly as you described to sort mine out.

Cheers.

 

[nickhalluk]

Many, many thanks for this info. I have been having the same issue since last year and even bought a new resistor pack to fix it, but that did not cure the problem (Waste of £80+). Your pictures and quick-fix suggestions were spot on and I managed to do exactly as you described to sort mine out.

Cheers.

Cool, I'm glad this info has helped other people out, I know it was "P"ing me right off until I got it sorted.

 

[j.a.racing]

thanks for this i was worried this was gona cost a bomb to fix. i did it using a sprung hose clip mite be a bit more durable than the cable ties. works fine now

 

[nickhalluk]

sprung hose clip

Nice move, think this might be the next upgrade for mine :approve:

 

[brownyboy]

Why oh why do i get all the expensive problems!!

Good info above sounds like i have the exact same problem. I ahve taken the centre console to bits and look up in the drivers footwell bit by the console and cant see anything that looks like the photos in this thread

help!!!!!!

 

[nickhalluk]

Why oh why do i get all the expensive problems!!

Good info above sounds like i have the exact same problem. I ahve taken the centre console to bits and look up in the drivers footwell bit by the console and cant see anything that looks like the photos in this thread

help!!!!!!

You need to unbolt the panel with the motors on it to get to the cogs behind.

 

[brownyboy]

Oh right that will explain it then - i took apart the centre console looked up in the drivers footwell side and saw a load of coloured wires so i am guessing its behind all of these somewhere.

Any you just tighten a cable tei around the cog? You had any problems since?

cheers for all your help

 

[nickhalluk]

Since I did mine, its been perfect, done a 2500mile road trip around France with it and never missed a beat.

 

[brownyboy]

having major problems getting to this cog. I have undone loads of tiny gold bolts (about 5 now) and still cannot manouvere the plate the motors are sitting on to get to the cog. Some of them are literally impossible to undo due to the stupid french putting the bolts in inaccessible places and putting big metal poles in the way!

I must be doing something wrong

Any suggestions

 

[brownyboy]

Got to it now!! I unscrewed all the ones that attached the motors to the plates. (what a c***)

The cog is not only just rounded off slightly there is also a split down one side so i have tried to put some glue in there and cable tied it up overnight.

If all else fails could i not just packed the inside of the cog with glue and then stick the motor end in it and then it will never fail lol

 

[brownyboy]

bump

 

[Mitchell]

I got climate control in mine but got the same problem, I can't seem to find the panel to take off to get to the cogs, so I presume it's different. Any help on solving it on climate control?

 

[nickhalluk]

I got climate control in mine but got the same problem, I can't seem to find the panel to take off to get to the cogs, so I presume it's different. Any help on solving it on climate control?

I have climate control!
It was over a year ago now, but if you put your head in the drivers foot-well and look at the centre console you will see a panel, remove this and you should see the back of them motors used for the climate. there is then a few screws holding them in place. remove them and the motor and there are the cogs.

good luck, should only take you 20mins or so.

 

[Mitchell]

done it last night! much better now, put some superglue on the cracks and tightened a cable tie around it cheers for the help

 

[Terry172]

If it hasn't been done already, nickhalluk or 1 of you should put a step by step guide together with pics and have it stickied in the guides section as I am sure there are people out there this will help and save them many bucks by the sounds of it....

 

[n-dre]

Some pics that might help (btw: english is not my mother langueage, so sorry for all spelling mistakes):

First if you look in your cars driver's footwell you should see this panel with 2 motors on it (circled green):

This panel is what you should remove to acces the cog, no need to remove motors from it.
You can remove panel simply by unbolting 3 screws (marked on pics with 1, 2 and 3), screw 3 is better seen in second pic below:

Remove panel with motors:

And now you should see damaged cog:

Now you just need to put something around it - cable tie, sprung hose clip... (fixed cog can be seen on pics that nickhalluk and j.a. racing posted), and put the panel back on its place.

I know this is not perfect for step by step guide, so if anyone wants to do a nice guide feel free to use my pics

 

[Tom|Nbk]

Bump, many many thanks for this. Did mine earlier, the 3rd bolt is an absoloute b*****d to get to as the steering column is in the way makes it an absoloute misery to get to. Anyway, the cog on mine was cracked similar to everyone elses so I cable tied it up and put bolts 1 and 2 back on. I left bolt 3 off so I can easily get the panel off again if I need to. It felt nice and secure anyway with just bolts 1 and 2.

Lining up the cogs to slot back in is also a nightmare so try not to move the cogs about much while you're under there.

Anyway I was quoted £800 to strip down the unit and sort this problem out, I have now sorted it myself for the price of a cable tie!

Very chuffed if a fiddly job. Now got my AC sorted for Summer!

 

[WILLIE]

Ive just had this happen to me in the 182. TRyed this step by step and it worked. Top notch

 

[motorola222]

aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaah im so angry i cannon get the panel off due to access problems the pedals and the steering colomn are right in the way

 

[BLUE-STORM]

mine is with the paddel , in the right side of the foot well , that conects to the part in the bornet , that directs the air pick up i belive , any one had this fault ??