Radiators not very hot

pinkfluffythings

Not long moved in, radiators not heating up to what they should be. I have tried to bleed them, no air coming out just water. Still not boiling warm. Help!

BOBS

Is your thermostat turned up ??

moneypooh

Do you have a speed option on your boiler pump? Ours was set too low and the radiators didn't get very warm, sped it up once and much better.
Are they the same temperature at the top and bottom, if not they may need flushing - another problem we had. Our system is over 20 years old and has a few glitches every so often.
Is your boiler working properly, we needed ours replacing after 18 years and that sorted out the heating nicely.

pinkfluffythings

Thermostats upstairs and downstairs both turned up full blast, boiled only 5 years old as this is a new house.
Will get OH to look at boiler when he comes home incase it needs turned up

Thanks for replies

Ebe_Scrooge

Do they have thermostatic valves on the radiators, if so are they fully open ? Also, is the lockshield valve ( the one on the other side, usually without a knurled turning cap ) open ?

If the system was properly balanced when it was installed, then you should find that the lockshield valve is probably only partially open. This is correct. However, you can do a quick test to see if it's causing the problem. On one radiator, open the lockshield fully, but make a note of how many turns you need to make. See if that cures the problem. If not, return it back to its original position to restore it to the correct balance.

Balancing a system is simple enough, but very long-winded - google will show you how to do it. But you don't really want to mess it up by adjusting the lockshields if you can help it, and if it is in fact already correctly balanced.

ginvzt

Sorry -what boiler is it?

We are in the process of changing the boiler (well, finding a tradesman), and we are looking at Viessmann boilers. We were told that with the weather compensation kit the radiators won't get as hot as they do now all the time, because of the way these boilers work.

Gloomendoom

Some boilers have a thermostatic control on the boiler itself which sets the maximum temperature of the heating water.

At least, mine does.

latecomer

First thing to check would be the temperature of the boiler. If thats set low then the radiators will never get very hot.
then the thermostatic valves if they are fitted.

As others have said - what kind of boiler is it? Combi or conventional?
Does the hot water work?