Cold Radiator

Lynfo

Having a slight problem with a radiator in my house. It's never been completely warm, I've been bleeding it for the last few weeks and a substantial amount of air has come out, however for the last few days no air or water has come out. The knob on the bottom is turned up full, as is the temperature - has anybody any suggestions before I freeze my ass off?

crosstownk

If your heating system is a sealed system then you may have released too much pressure and it now needs to be topped up. Near your boiler (most common location) there should be a pressure guage. This guage should read 1 bar when the system is cold. Every time you bleed you allow the pressure the drop so its possible that the system is now below 1 bar. Next you need to locate the filling valve for the system - this could be in the attic. When you locate it just open it for a few seconds and check the guage again. If you fill it too much just open a bleed valve to allow the pressure to drop off a bit.

Low pressure could also prevent the other radiators from heating up properly.

Lynfo

Thanks a mill will try that

coxy123

I have the same issue and the pressure gauge is at zero on the gauge of boiler and gauge on water cylinder - I will need to look for the filling valve as I have not seen it to date.

tapest

Hi
Whether it's a sealed system or not, If you bleed rad and you get no water and no air, then system is short of water.
I can't understand why sealed systems are installed with a valve to be left off most of the year...and no labelling of valves and poor instruction given to user . A much better solution ,in my opinion, is to leave the gate valve open but install a "non-return" valve as well just down stream of it. When system is cold water can automatically fill system to normal pressure. and when system is hot and pressure increases the pressure vessel copes with this . Also no possibility of system pumping back beyond a "non-return" valve. Unless I'm missing something ??
t

JamesM

If it is an open system and old, it could be a blocked pipe from the header tank.
The reason the valve is turned off is that with dirt and corrosion, a non return valve can sometimes not work and let dirty water back through the valve. At one time council inspectors insisted that the fill pipe actually be disconnected.
Jim.

Morkin

On a related note. I've a boiler that is losing abouy 1bar pressure per hour of use at the mo. Its gas based a someone is due to call out today but any ideas why this is happening?

New house and heating has only been seriously used in last few weeks. All rads have been bled and the system topped up but at this rate of loss I'm re-pressurising almost hourly

Thanks,

M.

crosstownk

More than likely you have a leak somewhere.

Morkin

Agreed. But how hard is such a thing to track and fix?

There are no signs in the ceiling or around any of the rads so I think the leak is at ground level or around the boiler.

Originally the pressure dropped slowly (about .1 bar every 3 -4 hours but after a 'service' yesterday it has reached the current rate of 1bar per hour of use

Thanks agin for any info.

M.

crosstownk

It could be that the pressure guage itself is dodgey and letting water out through the overflow. On most newer houses you'll see an overflow on the exterior wall where the boiler is mounted. Worth checking. I've also seen pressure vessels leaking too so have a look at this if you can. If its not one of these then its going to involve a lot of detective work.

Morkin

Thanks crosstownk, I know where that overflow is and will check - Might help if I had a few dry days as well (could cover the overflow with a milk carton lined with dry kitchen paper I guess and see how much, if any, water is leaking out)

Will update when I can,

M.