Central Heating comes on when Hot water is on

[lee mackreath]

hi we have recently moved into a new house and had a whole new sealed heating system installed.

we have a Worcester greenstar 30cdi classic boiler and control the boiler through a greenstar comfort remote programmable thermostat

we are not sure if we have always had this issue, but now it is summer we have our CH set to 'off' at all times as we dont need it on. we do however have the hot water set to come on for an hour in the morning and an hour in the evening. the problem is when the hot water kicks in all the radiators in the house go on also and the house becomes unbearably hot within half an hour. the only way to stop this is to either turn the hot water off or turn down the radiators.

my question is should this be doing this? does it matter that we have a sealed pressuirsed system? i have seen 'diverter valves' mentioned and i dont know if our boiler has one, should have one or has one thats maybe broke after 3 months?

any help would be appreciated

 

[flameport]

my question is should this be doing this?

No. It's either broken, or more likely was not installed properly in the first place.

does it matter that we have a sealed pressuirsed system?

No, that's entirely normal for new systems.

i have seen 'diverter valves' mentioned and i dont know if our boiler has one, should have one or has one thats maybe broke after 3 months?

There will be at least one valve, possibly 2. Although it's possible to have it inside the boiler, it's more usual to have them externally, often next to the hot water cylinder.

In any event as this system is only a few months old, get the installer back to fix whatever the problem is.

 

[boilerdoktor]

Can you say whether you have 2 port valves or 1 3 port valve

 

[dilalio]

hi we have recently moved into a new house and had a whole new sealed heating system installed.

we have a Worcester greenstar 30cdi classic boiler and control the boiler through a greenstar comfort remote programmable thermostat

we are not sure if we have always had this issue, but now it is summer we have our CH set to 'off' at all times as we dont need it on. we do however have the hot water set to come on for an hour in the morning and an hour in the evening. the problem is when the hot water kicks in all the radiators in the house go on also and the house becomes unbearably hot within half an hour. the only way to stop this is to either turn the hot water off or turn down the radiators.

my question is should this be doing this? does it matter that we have a sealed pressuirsed system? i have seen 'diverter valves' mentioned and i dont know if our boiler has one, should have one or has one thats maybe broke after 3 months?

any help would be appreciated

Get the installer back as this is likely to be a defective 2 or 3 port valve; wiring issues with the above; or even an issue with backflow from the cylinder return if it is not the last T on the boiler return... it depends on the extent of the work they undertook.

 

[CWHEATING]

If it’s an S plan it’s possible that the central heating zone valve is seized in the open position. They may have fit a new boiler but the zone valves were not replaced.

 

[oph]

Its entirely possible that the installer accidentally left the MV in the open position when filling the system.