Heater not running hot, any ideas?

redzed · 30-10-13, 06:04 PM

My heaters not running hot, I've fitted a new heater resistor so don't think it's that previous one didn't work at all and this one is meant to be a fully working unit. Anyway where should I start looking? Cheers guys for the advise as always

peterzs · 30-10-13, 06:14 PM

is the water temp gauge on halfway???

Thermostat OK?

Air lock in the pipes?

Blocked heater matrix?

talkingcars · 30-10-13, 06:23 PM

Air con or climate control?
Is it blowing any air?
Is the valve that controls the coolant moving?
(IIRC it is under the bonnet on the mk1 and in the heater box on the mk2).

MG ZS STE · 30-10-13, 06:43 PM

Even on Hi?

Dan1971 · 30-10-13, 06:46 PM

I has cold air in a ZT-T V6 I owned a while back. Had an air lock. Bled the system, worked for a while and I sold it. A short while later it happened again - it had HGF.

Not doom and gloom by any means, but it is what happened to me.

Mark S · 30-10-13, 06:55 PM

could be servo motor that opens that flap that directs air passed heater matrix.

MG ZS STE · 30-10-13, 07:10 PM

Running the diagnostic would eliminate any servo issues. Is it hold the auto when turning the key starts the cycle?

Skillen · 30-10-13, 07:10 PM

Quote:

Originally Posted by Mark S

could be servo motor that opens that flap that directs air passed heater matrix.

Would the test mode see that?
I can't remember now if it would.

MG ZS STE · 30-10-13, 07:35 PM

I'm sure it tests all the servos. You can hear them whirring away as it goes through the cycle.

petet16 · 30-10-13, 08:01 PM

For the self test, keep the auto button pressed and switch ignition to position 2.

The links and servos can be accessed from the drivers footwell, they're fixed to the side of the heater box so you should be able to see them moving as you change the temp setting and also as you change the direction of the air between screen and foot wells.