old (ish) system Back boiler, heating with "water only&

[rabu]

Hi, wondering if anyone can help with this annoying problem, have a relative who was asking me about her heating, i know some about it but couldnt think whats causeing her problem, that is, its a 80s system, with back boiler replaced for another back boiler in 1994, with a Danfoss Randall time clock on chiney breast and pump driectly blow under floor and thermostat in hall, each rad also has TRV's exept for bathroom.
The problem is that like now, she needs hot water but no heating, if the contoller is switched to "water only" she gets how water & The upstairs rads also come on, downstairs do as they should and stay cool. When set to water and heating, everythings works fine. So can anyone shed any light on whats causeing this problem of water only, still alowing upstairs rads to come on ? any help would be great. Thanks.

 

[swbjackson]

It's gravity circulation. The system should have had a check valve fitted, this is either crudded up or wasn't fitted. Simple solution is to turn all the upstairs rads off in the summer.

 

[45yearsagasman]

View media item 38774I agree. Look for something like this and replace it or do as suggested by swbjackson.

 

[rabu]

thanks for replys, Thats what she keeps having to do, turn all upstairs off each time she just wants hot water, wich is annoying when realy just flicking the switch should do that job. Cant say i noticed anything like the valve in the pic, when i changed the pump couple of years back, would this be located near the pump/ boiler? somehwere round the chimney.

 

[45yearsagasman]

If the pipes that feed upstairs are located say, beside the chimney breast(maybe concealed behind a panel) the said valve will be in there on the ch flow pipe.

 

[barrymanifold]

We used to dip the flow heating of the boiler on gravity systems never fitted check valves they block up to easily .

 

[rabu]

thanks fore the help guys, there is a pannel running up the side of the chimney so pipes should be in there then, not good since that pannel has been decorated with the room about 6 months back. At the momen shes had to do like what was said in pervious post, turn all upstirs rads off, then on again if she just needs them on for a bit, after few years it gets annoying.
If i can access the flow pipe for upsirs, is it as simple as draining down, chop into pipe fit valve, refill. job done? know refilling is tedious job as its got a primatic cylinder fitted, have refilled them beofour though so should be ok. Thanks again.