CH not working when HW/CH selected on programmer

[Billtaxi]

Hi I would really apprecaite some advice here, as i'm not great with DIY, and i'm getting the run around.

Problem: When selecting either HW or CH on the programmer (Landis & Gyr RWB2) everything works as it should, however if we select HW/CH together the HW works fine but only the first radiator in the system gets warm, the rest remain cold.

So far: A friendly plumber has changed the pump, and the motorised valve, and in the process drained, and refilled the system twice, checked and balanced/bled all of the radiators, but the problem still remains.

The feedback that we got was that the system might need a flush, as each drain contained sludge, however this was not something he wanted to do, and admitted that electrics are not his strong point and has now walked.

I thought that it might be the programmer not working correctly. Would a new one solve the problem?

Any advice on what to do next would be greatly apprecaited.

Cheers


Bill

 

[D_Hailsham]

Firstly, is this a new problem, i.e it worked OK last winter? Or have you recently moved in, so don't know what it was like last year?

Secondly, don't go throwing money at it in the hope of finding the solution.

 

[Billtaxi]

This is a new problem, the system worked fine last season, albeit the heating was a bit slow, but nothing to worry about.

I agree with you on the money front, perhaps we've been a bit to hasty?

 

[kevplumb]

which valve/s do you have
View media item 11149 View media item 11148

 

[StevenJames125]

is there a balancing/gate valve on the return pipe from your hot water cylinder?

 

[Billtaxi]

Hi Kev,

The valve looks like your top photo. It is marked as a Honeywell V4073A1 039 if that means anything to you?

 

[kevplumb]

you have a "Y" plan

i would check the wiring or have it checked first

y plan

• kevplumb
• 19 Sep 2009
• 22

 

[D_Hailsham]

OK, it's a new problem but the system wasn't very good last year.

Problem: When selecting either HW or CH on the programmer (Landis & Gyr RWB2) everything works as it should, however if we select HW/CH together the HW works fine but only the first radiator in the system gets warm, the rest remain cold.

Sounds as if the cylinder is starving the heating system, which would be a balancing problem.

Is there a valve on the pipe into or out of the side of the HW cylinder - not the motorized valve - similar to this (it may not have a handle):

View media item 27772
If there is, try closing it down half a turn at a time and see if it makes any difference. What is happening is that the path through the cylinder is easier than through the rads, so most of the water goes through the cylinder, starving most of the rads of any flow.

 

[Billtaxi]

Hi Steve,

Sorry I'm a total novice so you've already lost me here. What am I looking for?

 

[StevenJames125]

a valve on the return pipe from your h/w cylinder as in the picture above by D Hailsham

 

[Billtaxi]

Hi Guys, yes there is a valve on the outflow pipe. I'll adjust as suggested and let you know what happens later.

Thanks for your responses.


Cheers


Bill

 

[Billtaxi]

Hi Guys, just to let you know that having adjusted the value as suggested, it has made a huge difference, and we are now getting both HW and CH when selected together on the programmer.

Thank you for your help and advice, which has been very much appreciated, and saved us more outlay.



Cheers


Bill