radiators on with hot water

[Donquick]

Hi all,

I realise this is a reasonably well trodden path but I can't find the exact topic covered.

I have an s-plan system with an external boiler. this means that the feed and return from the boiler to the rest of the gubbins in quite a long way (~10m) The feed comes from the boiler then to the pump. The hot water branch and the heating branch then separate and then there are two moterised valves as you would expect. Both valves are doing their job and the pipes beyond them stay cool when they are supposed to be closed. So that is all good news.

However, the radiators on the ground floor are getting hot when just the water circuit is on. This is happening due to water travelling down the return pipes from the rads not becasue of a valve failure.

I remember when talking to the plumber in my last house (a y plan system with a triple valve - is this right?) he said that the order of the returns back to the boiler return pipe was important and i am wondering if this is relevant to my current situation.

The return order is downstairs rads, then hot water cylinder, then upstairs rads.

Anybody know the possible cause of my problem; or perhaps it is to be expected with the setup i have.

Thanks for your help or comments,

Don

 

[45yearsagasman]

Reverse circulation is (probably) what you've got. There should be no connections after the cylinder connection into the primary return back to the boiler. View media item 32248

 

[slapper]

Reverse circulation is (probably) what you've got. There should be no connections after the cylinder connection into the primary return back to the boiler. View media item 32248

Or, Last man in

 

[Donquick]

Hi guys and thanks for the feedback. I think that probably clears it up then. I have done a little more research and notice that there are several return branches beyond the cylinder one. As the boiler return travels back throught the ceiling several of the radiator loops come back that way.

I can get to 'last man but one' reasonably easily by doing a little pippework. Is it worth it or would i need to get all the way to literally the last return to make any difference would you think.

Thanks,

Don