Post
by marrtin »
Fri Nov 02, 2007 12:54 pm
I think you have far more to worry about than the possibility of a leak. The heating system is regarded as a secondary enclosed system and is designed specifically to exclude fresh water containing oxygen from entering the circuit. Air (Oxygen) entering and being circulated will cause extreme corrosion within the system and eventual failure of radiators and pipes. The resulting rust will also cause a build up of black slurry which will at the best reduce hot water flow.
If we assume the header tank is full of water, it may be the system is poorly designed and air is being drawn down the expansion pipe when the pump starts up. If the pump is set at speed 3, try reducing it to 1. This may cause some of the rads to stop getting hot, so may not be a solution, but may stop the air being drawn in.