Central Heating question

[Whickerman]

Just had a new copper cylinder fitted, my pumped central heating (sealed system) runs through the coil inside. Out side the tank, there's the inlet and outlet for the coil. At the top of the top pipe there's the air bleed valve (I think it works by allowing any air trapped in the system out when you press the valve?). The plumber told me that this may well show a small dribble of water once or twice in the first few days, and it has. How long should this happen? Is it simply the system finding the correct pressure? Note that this is an old system - there's no pressure gauge. Thanks

[ACB312]

I have fitted a similar system in my own house. I presume you have a boiler and pump with motorised valve(s) to divert the heated water to either or both the radiators or the hot tank coil. I have a simple stop end joint on the upper end of the coil and bleed the air out after any maintenance. This usually only needs done once. You appear to have a valve that is semi-automatic - possibly with a membrane that fills with water and shuts off as it swells - similar to those that can be fitted to radiators - so it may drip a little till the membrane has swollen, or may just need tightening up slightly - usually a fractional clockwise tightening of the obvious screw or nut. Hope this helps. Cheers, Andy

[Whickerman]

Cheers Andy