Hi all
Think that the expansion vessel on my Vaillant vcw sine 18 boiler is broken
Pressure leaps up soon after boiler fires up and dumps some water out of the prv
pressure is then low after boiler cools
I think that an external expansion tank is the answer
I have seen them at about 20gbp for the 8 litre I need
My questions are can I just connect it direct into the pipework with 15mm copper without the pressure gauge sold as a option with most vessels (my boiler has a pressure gauge built in) and the 3/4 bsp thread would I use a standard tap connecter on that?
Regards
Tony