DIY Doctor UK DIY Forums

I have a conventional, fully pumped central heating/hot water sytem via a gas boiler and with a hot water storage tank. I have turned off the CH for the summer but kept the HW off the boiler. However when the boiler heats up the tank it also heats up the radiators.

The motorised valve on the CH sytem works OK because it is hot on the boiler side and cold on the other side. However i can feel water vibrating (circulating?) through that side. Could there be some other point where there is a cross flow between the CH and HW systems.

Thank you

Terry R

Check actuator and three port valve, that'll be where the problem lies.


htg

Thank you but i am afraid i do not know what an actuator is.

I have 2 two way valves fitted and they have both been changed recently, trying to solve this problem, and are working ok.

Terry R

Sorry, you do not have a 3 port valves.

The actuator, also known as a motorised valve/head, is the elctrical part of the 2 port valves. The actuator sits on top of the valve this is what turns the valve to the desired position.

Double check the two port valve and post your findings on here.

I can't see it being anything else, unless at somepoint someone has tee'd into the hot water flow and return instaed of the heating ?????

htg

I have double checked the 2 way valves and they are definitely working as they should be.

It is a DIY installation by the previous owner so it looks like he has somehow interlinked the 2 circuits. Is there a likely place he could have done this which i can check without tearing the house apart?

TerryR