Heater in Corsa not working

[Philtw]

I have just found that the heater in my M reg corsa has stopped heating up. The blowers are still working-but no heat, can anyone tell me what the problem can be and how to remedy this?

[homer75]

I had the same problem with my daughters L reg Corsa. Could be a blocked heater matrix or an air lock -- feel the pipes running thru the bulkhead to the heater when the engine is warm. if one of them is cold then you may have an air lock. You need to remove the return pipe (cold) and allow the air out with the engine running. You will hear the pipe hiss and spurt as the air is released. Top up the header tank. This cured the prob on my daughters car. If this doesn't cure it you will have to reverse flush the heater matrix. Connect a hose pipe to the return (cold) and remove the other pipe ( hot) force mains pressure water thru the matrix for 10 mins then reconnect pipes and bleed for air as at the beginning. Hope this helps.

[ianess]

Do you have a leak somewhere? If nothing obvious......
When did you last check the fluid level?
Does the heater work OK when expansion tank is at correct level?
You could be losing coolant out of the exhaust pipe if your head gasket has blown and water is leaking into the combustion chamber. You may notice a lot of steam being blown out.
Is there any sludge inside the oil filler cap? An almost certain sign of head gasket trouble.

Worst case scenario could be expensive. With any luck it may be something relatively simple.
Good luck.