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zr heater not working

11K views 30 replies 14 participants last post by  martineevans1 
#1 ·
#7 ·
sorry to ask but do these heater resistors also stop heat working on all settings ? eg 1 to 4

I have no heating and after exploring everything single other option (and believe me ive spent 3 months doing this) the only option i havent explored is this heater resistor which is why im asking.

I have air blowing on all 4 settings but just cold!
 
#11 ·
if air is blowing on all 4 settings its not the fan motor resistors which is what these guys were refering to. your problem is your heater matrix either has an air lock, is clogged up with crud or your heater matrix valve is not working (or the hot/cold knob is not controlling the heater valve)

a common sign of head gasket failure is the heaters not blowing hot air so it might be worth checking your oil (does it look ok? any signs or a mayonaise like substance)
check your coolant..... are you loosing any? does it look ok or does it look all gunky with possibly oil in there?? (again this might be the same mayonaise like substance)

there is plenty of posts about heaters not blowing hot air and head gasket failure and they are quite often linked, however not always so dont panic just yet.
the search button is your friend, dont be afraid to use it. hope that helps some what
 
#15 ·
whats the flow of water light when you flush the matrix?? just a trickle?
it might be worth seeing if you can stick your hand under the dash (or in the air vent chamber) and feel the matrix its self. might be easier if you feel the metal pipes going to and from the matrix (they stick through the bulk head into the engine bay) one might be hot one might be cold.

try shutting the matrix vlave (turning the dial to cold) starting the engine and letting it warm up) then feeling the pipes get someone to open up the valve and both the inlet and outlet pipes on the matrix should become hot/warm

how do you fill the system up with coolant once you drained it? very very slowly i hope (with the heater turned to hot) otherwise you will get air locks.

i had a similar problem with my old 216, after a head gasket change i could not get my heater to blow hot again, i tried draining and refilling, bleeding, flushing it all seemed ok but at best all i could get was luke warm air. i never got it fixed but i sold the car now.
 
#16 ·
The flow of water from the matrix was just the same as i was putting in which suggested to me that it wasnt that clogged up after a few tries.

I will double check the matrix inlet and outlets again as you suggested starting on cold and then changing to hot as both should be hot/warm if the water is flowing through right?

when filling the coolant i didnt do it extremely slow as didnt also want air getting in but i didnt stop and start neither and on the occassions i've done it ive just done it at a constant flow.

the only thing that i can think of is this heater valve is not fully working and the hot water then must be going via the bypass.
If i take the 2 hoses of the heater valve, will i be able to see immediately if the valve is ok?
 
#17 ·
ive never taken apart the valve before but it should be fairly simple to check once the pipes are off either end. yes inlet and outlet should be warm/hot if its working.
if the valve is working properly then the pipe on the inlet side of the valve should be hot when engine is warmed up and valve shut. with valve open both inlet and outlet of the valve should be hot if its working/allowing water to pass. although heat can transfer so the best way would be to whip the valve out and check it
 
#19 ·
I will have another look as thats one of the first things i checked and from what i can remember both hoses on either side of the valve were hot. I then had to move on to other suggestions with no result on anything i have tried. The reason i didnt actually take the valve apart was because the hose was indeed hot on either side which suggests the valve is opened or at least opening but it may be obstructed slightly causing problems. So i will check this again and go from there.
 
#25 ·
as youve had the pipes off they do tend to weld themselfs on using some spare pipe (from scrapyard or hose pipe bypass the valve completely the heater should only blow hot if still cold do you have a thermostat fitted?how long hasve you owned the car?should be fitting winter one now anyway check all the thinner pipes are free flowing using some old mains cable (not twin +earth)they colapse inside but look ok from outside the system is self bleeding with expansion tank at highest point infared thermometers from catering and medical industry are pretty cheap now and allow you to check pipes/rad etc just by pointing laser at different points
 
#28 ·
Heater not working on 1 & 2 speeds

The reason the heater stops working on 1 & 2 speeds is because the
resistor pack has packed up and most of the time the reason for this fault is the heater motor bottom bearing dries up and become difficult to spin therefore not being able to cool the resistors, they become brittle and break . When you replace the resistor pack remove the heater motor (3 Philips screws and it drops down) and spray liberally with WD40 and replace. This is what I did and it worked great. All I did to the resistor that had broken was to clamp the two ends together with 1mm wire and it worked properly.
 
#29 ·
Streetwise 1.8 petrol with Auto gearbox & 2005 model:
We have just had a heater failure with no other symptoms. The heater valve Bowden Cable was working and the heater valve lever was working. The solution was to replace part PCH003300 described as Hose assembly-engine coolant valve - with Saab valve - Genuine MG Rover and is pictured on the RIMMER website. It comprises a complex collection of liked hoses & cost £48.41 plus vat. Hope this helps someone.
 
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