The blend door is probably stuck.
Same problem vectra heater only blowing cold checked water coolant and it was empty. Topped up now blowing hot just hope I not got head gasket probe
new heater
the heater matrix is blocked
if engine temperature ok, either air lock/blockage in heater exchange matrix or problem with heater control cable. in my case it was the headgasket on its way out. from dom coolent level stops it to if too low!
Check the temperature gauge. If it is running cold, replace the thermostat.
i have 2004 sxi petrol and have same problem if you have had it repaired could you please put it back on here and let me know
No
Low coolant? Heater core airbound, resgtricted, or plugged? Bad thermostat? Heater control cable not adjusted properly?
Your heater will blow cold air only.
Either this is a plumbing mistake or the cold water has been switched off and the hot water heater is draining. If no cold line valve has been turned off. It may indicate a burst pipe.
you could have the recirculation turned on. that would be on the heater control, make sure you are using it on the vent setting. if that doesn't fix it then you have a bad heater core.
When it is first turned on it blows cold air. Give it 2 minutes it wll heat up to regular temperature.