No hot water upstairs when downstairs is open

[shaf]

Hi,

Firstly, I would like to say hello to everyone as I have just joined the forum.

Right, to the problem.

When the hot water tap is open in the upstairs bathroom whilst the downstairs tap is running - the water upstairs stops or trickles.

I live in a terraced house which used to be two house before being converted to one 10+ years ago. The problem has always been there since then. I've always put it down to the boiler not being powerful enough ( Worcester 28CDi).

I've now had a new boiler installed in (Worcester 37CD Greenstar) and I still have exactly the same problem. My plumber has no idea why.

I was wondering if anyone has any ideas as to what might be causing the problem? Should the boiler be able to run both taps?

Please let me know if any further details are required.

Thanks.

 

[twgas]

cr4p water supply is first thought, does the tap upstairs stop when you run a cold one?

 

[shaf]

No the hot tap water is not affected if cold is turned on downstairs.

 

[John506]

Generally if you are looking at running multiple hot outlets an unvented system is more prefered.

Did the plumber bother to check your flow and pressure before even considering any decision to how he would supply you with hot water?

 

[twgas]

Is the inlet valve turned fully on?
filter clean (if fitted)?
any other valves that may be turned partially off?

 

[shaf]

No, I'm afraid the plumber did not check the water pressure before installing the boiler.

I have had this checked a few months ago and the pressure was 11 or 12 litres I believe. This does not mean much to me but does that sound ok?

 

[shaf]

Is the inlet valve turned fully on?
filter clean (if fitted)?
any other valves that may be turned partially off?

A new filter was installed and I believe it is clean.

I can ask the plumber regarding the valves as I do not know. If I am getting water upstairs when only one tap is on then does that tell us anything regarding the valves? What do these valves control?