Heater blowing out COLD AIR!!!

[matto]

Alrite people.
When my heater dial is on the red section (for hot air) it stills blows cold air out of the side vents.
My engine is in good nick so its not down to that. Could it be the heater matrix?

Any thoughts would be appreciated

Cheers, Matt

[Chris LR]

Broken vent cable
Sticking thermostat
Humar error

I'd go thru it in that order.

[frog_southampton]

my heaters have packed up all 2geather!

[Ballsy]

have you got water in the system?? cause that makes it blow cold if its totslly empty!!!

Ballsy

[Dave]

can i put a pound on thermostat?

[mikeyredtop]

ive had to cables go on me they snap off the black box under the dash and when u turn the dail it aint doin nothin..

[Novas.5u.com-Chris]

Very Very likley to be the heater cable from the knob to the adjustment lever on the side of the dash. Take the passenger side under dash shelf out and look on the side of the heater box, there is a flimsy metal arm with a cable attatched which goes up towards the radio (mk 2dash). Try moving the heater knob and see if the arm moves. if it doesnt then you will need a new heater cable.
I know this because mine does exactly the same. There is a clip which holds the cable end onto the heather box which breaks very easily. I tried arolditieing mine back on but it only lasted a couple of days then came off again.
Hope this helps.

[bad_boy_nova]

If you've got water in the engine and the temperature on the gauge is normal when driving and the cable for opening the flap next to the matrix is ok, then im certain that it will be a blocked matrix.

[Alex]

cable, cable, cable!

[matto]

Cheers for the advice people.

I'll have to check the cable - never thought of that!
Next i'll check the matrix - pain in the arse though! How do i clear it if its blocked?

I would of thought that should sort it as the above seem popular probs with the heaters.

Matt

[bad_boy_nova]

If the matrix is blocked, you will have to get a new one. I had a nova with a blocked matrix once and i tryed flushing it out with absolutely everything but it remained blocked. I bought a brand new one for 47 quid. Ive got one in my garage that you can have for a tener if you need it.

[Lee H]

Take the plastic cover off the bottom of the heater matrix and see if the matrix is getting hot. I had this problem and matrix was fine but cable was knackered and not opening the flap. The cables are no longer stocked at Vauxhall either as far as I know :(

[frog_southampton]

what part is the matrix?

[Jules]

Broken vent cable
Sticking thermostat
Humar error

I'd go thru it in that order.

Also it could be an airlock in the system

[Chris LR]

Which can be caused by human error... :P

If you Matrix is blocked, it will mean that water isn't circulating around the engine, which will mean it over heats. So a blocked matrix is unlikely.

With the warm weather we've been having you've probably had the heat control on cold, so if the cable has broken thats where it will be stuck.

frog- the matrix is a small radiator - about A4 size or slightly smaller. It is fed with warm water from the engine and they sends it back again. Basically air is pulled thru and so you get hot air. It's a bastard to get out especially if it's a Mk2 with a center console. Took me about 3 hours.

[Chip_RB]

Which can be caused by human error... :P

If you Matrix is blocked, it will mean that water isn't circulating around the engine, which will mean it over heats. So a blocked matrix is unlikely.



By "blocked matrix" i would think that people are referring to the air ways in he matrix blocked so that the air cant circulate through it properly rather than the matrix blocked for water.

my money is on the cable, ive had a couple do that.

[bad_boy_nova]

If the matrix is blocked, the engine temp will stay the same, it wont overheat because water will still go round the engine, but it would just not go through the matrix. A matrix could get blocked with rust particles in the coolant or with radweld. Its easy to change a heater matrix. About an hour at the most.

[broony]

Better hope that your head gasket isnt away!
The 1st sign i got was that the heaters were cold due to no water in the tank due to the blown gasket.

But as long as theres water in the tank, then i would go for the matrix.