central heating function

[collo180]

My daughter has an old system in her house whereby when you call for hot water, everything works fine.
Just the dhw, radiators stay cold
When you call for heating, you have to have the dhw on, and the heating cuts out on the dhw tank thermostat.
The system appears to be a fully pumped open vented s plan?

Is there a faulty valve?
is there a valve fitted?
There is the supply to the boiler, and the tank stat wiring only at the time clock, which makes me think there is no valve, or not wired?

any thoughts please guys?

 

[Whitespirit66]

Have you found any motorised valves like the one below?

If you only have one of these valves, then the system may be designed to work the way it does. If that's the case, you may be able to make a few small changes and add a second valve to make it S plan with seperate control of hw and ch. As it is an old system, this is the most likely scenario.

If you already have 2 valves, then your system is already s plan. In that case, the ch's valve may be faulty.

Untitled

• Whitespirit66
• 4 Feb 2013
• 4

 

[collo180]

thanks for the reply, i have not found any valves or any wiring anywhere, i guess i will have to have all the floor up, are there any likely locations for these valves?

 

[twgas]

Post a few pics of what there is, blr pipes around airing cupboard, pump etc, we may be able to advise before floors come up.
Valves are often in airing cupboard or near the pump.