Replacement of a homeywell three port valve

[Callumjb]

I have recently changed a honeywell three port valve for a member of staff from where i work along with this fitted a new vented hot water cylinder. As her radiators upstairs were getting hot when the hot water was on. So thinking that the three port was stuck in the mid position i recommended changing it. Fitted the new cylinder exactly how the old one was piped up, Filled the system back up and tested all fine. Customer rings a day or two later saying that the same thing is happening? I'm abit stumped as to what is happening, and havent had the chance to reattend to diagnose what is happening. Any idea's as to what it could possibly be?

Callum

 

[king of pipes]

When the hotwater is on the heat is creeping down the common return and heating the radiators a easy fix would be to install a nrv in the return . kop

 

[Callumjb]

When the hotwater is on the heat is creeping down the common return and heating the radiators a easy fix would be to install a nrv in the return . kop

So am i right in thinking that its reverse circulating around the system through poor design? Where abouts on the return would i have to put a nrv? I've not had the chance to ask the customer if it did this before, but what if it didnt prevously do this?

 

[Callumjb]

 

[king of pipes]

You will need to take a few floor boards up to find the return and yes i wouldnt say bad design but water will find the easiest route block that with a one way valve and you should be sorted cheers kop