My heating hasn’t worked for some time. Probably just after I had the air con fixed. I have read that if the cooling system isn’t bled properly then this can cause an air pocket that will cause the control valve to get stuck. I am assuming this is refering to the coolent not the air con coolent. Anyway, I am thinking of replacing the heater control valve. These are the steps I have so far:

1) disconnect electrical connector
2) remove control valve from side wall
3) disconnect all three hose clamps and perhaps let water run from hoses.
4) connect hose clamps to new heater control valve and replace on side wall.
5) Fill up coolent again.

Any further comments would be appreciated. Do I have to do anything to get air pockets out? Should I drain another way?

Lately, I have had to keep topping up coolent (ie water).

regards