hi people ,i hope someone out there can help me ,i have got a hetra sadia central heating boiler and suddenly on tuesday the downstairs radiators stopped working ,but the upstairs ones are piping hot ,we also have hot water like normal ,the boiler is in the kitchen ,and emersian heater is in the main bedroom,we have 4 rads upstairs,and 4 down stairs ,we have tried bleeding the system and the rads came hot for a couple of hours but then went cold again ,i have bled 2 buckets of water from it but to no avail,

please help if you can

codeman

Do you have thermostats on the downstairs' radiators? If you have, could they have been turned down?

Well I aint a plumber, but if the rads are hot as hell upstirs & cold down then it sounds pretty obvious that the pump has failed!
Heat rises & all that? :confused:

Turn off the ones upstairs and see if you can force the hot water through.
Have you had any work done on the system?

no we have never had any work done on it and we dont have any stats per radiator ,no one has touched anything it just went wrong.

codeman

I've got to go to a house with this problem tomorrow. I went today and changed the pump but it's still having trouble so I'm going back tomorrow to turn off all upstairs rads and see if it'll force the hot water through. If not it's going to be a case of flushing the system out and putting some inhibitor (chemical to stop things from clogging up) in the header tank. The system is really old though and the boiler is a nasty old Thorn M 40, floor standing boiler.

Have you tried turning the pump speed up a notch at all because that's the first thing I'll be trying tomorrow morning. :) There should be a small switch on the side of it, depending on how old it is of course.

well ive just found out if i turn the upstairs rads off then the downstairs ones work ssttrraannggee

any ideas now people
codeman

Sounds like the system might need balancing. You could try turning the upstairs rads on halfway and see what happens. This should still force most of the water through to the downstairs rads but you should still have enough flow left for the upstairs ones.

Let us know how you get on. :thumbsup:

Dont bleed the system with the heating on. This sucks air in if the heating is on

hi ,ive found out if i turn the upstairs rads off the downstairs come on ,then turn down off the up comes on ,,how weird is that

codeman

ive found something new ,i think its the pump as its making a slight noise that doesnt sound right,
pauly ive tried that but the downstairs still dont work,wheres the best place and cheapest place to get a pump from

codeman

HORAY!!! ive sorted it ,it WAS the pump ,clogged up with s*&t ,so ive changed it and bough some rad flush stuff but i have to put it in the header tank but which one is it the big tnk in loft or small tank ,whats the other sorry to be blank but i dont like plumbing only electronics,

cheers for your help people
codeman

It's the small tank matey. Don't put it in the big tank or you'll poison yourself next time you use hot water in your cooking! :o Can't imagine it doing your skin much good when you take a bath either. :gag:

Small tank = Header tank for the central heating
Big tank = Tops up your hot water cylinder when you run the hot tap

:thumbsup:

Don't just tip it straight into the header tank. Drain off the system partially,and then pour it into the tank before filling back up. This will ensure all the treatment gets fully into the system rather than just sitting in the tank.