plumbing & heating

nadiahealy

hi,a neighbour of mine recently had her heating system up graded,she got the hot water and heating zoned seperately.there is a twin coil cylinder, oil one side the other stove,both sides have an expansion pipe going to header tank in attic and cold feed to stove,the new valves are on oil side,everything is ok until you just want the coil to heat up for hot water and valve to rads is off.it begins to pull from cold feed on tank which must be through the return on rads and up expansion which means cylinder and header tank is heating,turn on rads then everything goes well again would, pump be to strong just to be going round coil?

pache

Tis plumbed incorrectly and will need to be rectified without delay!!

nadiahealy

yea cheers figured something not right,would anyone have an explanation why this is happening?i turned pump speed down to 2 but no effect.thanks

Outkast_IRE

usually caused by the cold feed and expansion pipe connecting into system in the wrong place or places.

Would usually rectify it by placing the cold feed and expansion tees into the system as near as physically possible to each other, obviously would need to look at setup to confirm this would work.

nadiahealy

flow and return from oil comes into hotpress tees off to rads then goes on up to cylinder coil then tee off the flow on coil and up to expansion tank as the vent pipe,the other side of cylinder stove flow comes in and tees off to rads up to coil and tees off again to expansion tank as vent pipe,the return then comes in tees up to return on coil and tees off again up to expansion tank as this is the cold feed.after the tee on return from stove that goes to coil return nrv is fitted and pump then onto return rads,pumping into return of stove.