my upstairs radiators are only luke warm

aaronlim

i recently tried to balance my system up stairs rads were not working at all but i read some threads on this site so now up stairs rads are luke warm its an old system and was out of use for 4 or 5 years any ideas ?

Irish Steve

Several possibilities,

What fuel, gas, oil, or solid fuel.

If it's solid fuel, it might be sludging, which will need a power flush

Have you tried a bleed key to get the air out of the radiators upstairs?

Have you tried turning the radiators downstairs off, and if you do, do the upstairs ones then get hot, if the balancing was wrong, it's surprising how little the check valve has to be open for the rads to work, and if the downstairs ones are still open too far, the heat may still not be getting upstairs, as a guide, most radiators downstairs will only need to be open by about half a turn from fully closed on the check valve. If they are a long way away from the pump/boiler, they may need a bit more, but the upstairs ones are the priority here.

Has the system been drained down at any stage over the last few years. If it has, it's possible that there's an airlock in the return pipe to the boiler, and getting that out may be "interesting", one way will be to turn the hot end of an upstairs radiator off, turn the pump off, and then open the bleed valve, if there's no air in the radiator, use an old rag or similar to direct the water flow into a bucket, and let it run for a while, as fast as you can cope with, if there's air in the return line, this may move it. Another plan would be to turn all bar one of the upstairs radiators off, then make sure that both valves on that radiator are full open, and if there's a speed control on the pump, set it to the fastest setting, and turn the heating on again. If the upstairs rad doesn't get hot now, there's something else wrong.

Another thing to check would be if the system is open vent, (a second small tank in the roof area for the heating system as well as the larger storage tank for the hot water system) or pressurised. If it's pressurised, check the reading on the pressure gauge, if it's below 1.5 bar then the system may need topping up, and if you are getting any air out, and it's pressurised, you will definitely have to top up the system to bring the pressure back up. Exactly how that's done will depend on the system, and where the loop to top up is. If it's open vent, make sure that there is water in the small tank, and that the ball valve hasn't stuck and the level in the tank has dropped,

If the one radiator upstairs works, open another and close the first, to make sure that one is OK, and repeat for any others upstairs until they have all been checked, then open them all again, and start balancing them again, along with downstairs. and don't forget to set the pump speed back to where it was.

Hope that helps

aaronlim

well steve

the system is oil but we also have a back boiler on the fire in the sitting room
the down stairs rads are a quater of a turn open and are pipping hot it takes about 2 hours for the upstairs ones to get luke warm and they only stay at that. the back boiler is controlled by a pump and fuse spur but we rarely put that on its mainly the oil we use. my head is wrecked with this

Irish Steve

OK, if the downstairs rads are getting well hot, try closing them so that there's no flow on them, does that change the speed the upstairs rads heat up at? Try closing all bar one of the upstairs rads, and then open the check valve on that rad fully, so effectively, there is just the one rad on the circuit with no flow restriction. In theory, and yeah, I know, theory is a wonderful thing, one rad fully open should get hot pretty fast.

If it doesn't, then there are several possible scenarios. The first is that the rad is partly sludged up, which is a possible with a back boiler as well.

There may be an airlock in the pipes to upstairs, that's why I'm suggesting try just one rad open, If the pump has variable speed settings, try running it at max speed when just the one rad is in the loop.

If the one rad gets hot, try adding in any other upstairs rad, and see if that also gets hot. Add other upstairs rads as appropriate, and see if they also get hot.

If they do get hot, try adding back in some of the downstairs rads, and see how that works out.