I've got a pressurised heating system, ie no header tanks with pressure being provided by the mains water, which has a minor problem. The hot water tank has a vent pipe (which is fitted with a temperature/pressure fitting) which drips when the boiler is on. I have looked on the web and found that these tanks should be vented periodically by carrying out the following:
1.. Turn off feed to tank (mains). 2.. Open lowest hot tap. 3.. Open press/temp valve and leave open until glugging stops (several minutes). 4.. Turn on feed to tank (mains). 5.. Turn off hot tap. I have done this and the dripping stopped for a couple of days but it has now started again. Does anyone know how to resolve this problem as I cannot understand how the air in the top of the tank is being displaced by water.
Regards
Mike