Radiators only luke warm if hot water is on

[SukyWuky]

Radiators are only getting luke warm if hot water is on but boiling hot if hot water is turned off. It’s either hot water, warm radiators or warm radiators hot water cavy seem to enjoy both anymore. We had the system professionally power flushed in Feb this year so what could the problem be. Thank you.

 

[Deleted member 120897]

I’m guessing you have a hot water cylinder and an s-plan or y-plan setup? If not, can you tell us what system you have?

I’m also guessing you mean hot water warm rads, or hot rads warm water?

 

[SukyWuky]

I’m guessing you have a hot water cylinder and an s-plan or y-plan setup? If not, can you tell us what system you have?

I’m also guessing you mean hot water warm rads, or hot rads warm water?

Good morning and thank you for your speedy response.

We have an emersion heater upstairs in the airing cupboard and a cold water tank in the loft. Downstairs we have a gas boiler (not a combi boiler) for the central heating and hot water.

As for the s-plan / y-plan question I’m so sorry but I haven’t a clue what that is! How do I find out please?

Thanks again. xxc

 

[Deleted member 120897]

An S-plan is x2 motorised valves independently controlling heating and hot water, or both on together. A Y-plan is one motorised valve, also known as 3 port mid position valve, which still does the same, just one valve as opposed to 2 and usually a higher failure rate. The way to find this out is to go to your airing cupboard and just after the circulating pump (usually) should be the valve(s). If you’re unclear still, take and upload a photo of airing cupboard and we’ll be able to tell you.

 

[SJB060685]

Take a photo of inside the airing cupboard please. It could be a balancing valve has been left fully open and the cylinder is sapping up all the energy when both HW and CH are called for.