Radiators getting warm when heating water cylinder

[bexman77]

Hi there, slight issue with my central heating system. When I switch to hot water to heat the cylinder the upstairs radiators get hot, tried turning the rads off but then the downstairs ones get hot!
I've opened the valve and turned it manually and all seems fine, as well as the valve I have a switch which I suspect may be the issue, these are photos:
https://flic.kr/p/JS4BVD and https://flic.kr/p/JS4C1Z

Appreciate any help anybody can offer.

 

[Dan Robinson]

Reverse circulation.

 

[bexman77]

Thanks Dan, how do I fix it?

 

[Dan Robinson]

Find the last return on the heating and move it to before the hot water return.


Assuming that's the cause.

With the hot water heating feel which pile of a rad is warming up.

Now turn on the heating.

If that pipe now cools and the other side heats then you have reverse circulation.

 

[bexman77]

Thanks! I think I understand, but I'm not so sure, I should have also said, the cylinder does get warm and I then do get hot water but it's as if the system is trying to heat the radiators and heat the hot water boiler, does that make any sense?

 

[Cgas]

Does that valve have 3pipes coming off it or 2? Probably the valve passing.

 

[bexman77]

Just the two pipes, pic attached. Thanks

 

[Cgas]

Just the two pipes, pic attached. Thanks

I ment the other picture (silver head) is it a 2port or 3port valve?

 

[bexman77]

Ah apologies yes, that has 3 pipes, pic attached. Not sure if you could make it out on the original pic but that 3 port valve switch is stuck in the middle, either side it has auto or manual but it's in the middle at present.

 

[FiremanT]

Reverse circulation.

Why would that be, if it was working okay previously, rather than a passing valve?

OP: was it working okay previously?

 

[bexman77]

Yes it's worked fine since we moved in 8 years ago but this summer turn the water on and the rads get hot too

 

[Dan Robinson]

Why would that be, if it was working okay previously, rather than a passing valve

I've come across system that worked perfectly fine for a while then start doing it. Hence i told the OP how to quickly check .

 

[Steelmasons]

Find the last return on the heating and move it to before the hot water return.


Assuming that's the cause.

With the hot water heating feel which pile of a rad is warming up.

Now turn on the heating.

If that pipe now cools and the other side heats then you have reverse circulation.

Fook me Dan , bit deep for a passing MV.

 

[bexman77]

Strange thing is, this morning I took the pic of the 3port valve and the switch was central, tonight the switch had moved to auto, put water heating on and once again radiators got warm...switch is still set on auto

 

[Dan Robinson]

Its not a switch. It is a manual lever for when the motor dies and for filling the system.