Bleeding radiators problem

[eggy1970]

I am having problems with my heating system.2 out 5 of my radiators are not working as they should. The 2 non working ones are the ones nearest the boiler ( i live in flat, all on the same level and have a glow worm series 2 boiler). I opened up the bleed on the non working rads and took out quite a lot of water while the heating was on, the rads heated up then went cold again very quickly. I then read that it is best to bleed rads with the system off. I then repeated with the system off but they still do not function. I would appreciate some help from any experts out there in cyber world.
Thanks
Eggy1970

 

[Plumber Will]

It sounds like the retun valves on them are closed! Open both valves on each rad.

 

[eggy1970]

Hi
You mean open up and bleed both top bleed valves,if this is the case i have tried this and still no luck. I have also tried fully closing in the thermostat on each radiator with the heating off ( which i believe is the return line) and totally filling each radiator, then switch the heating back on then opening the thermostat this does not work mate i am totally baffled, it seems such an easy thing to do.

 

[breezer]

plumber will is refering to the other valve on the radiator, not the bleed valve

 

[Plumber Will]

The pipes that feed the rad....one will get hot before the other this is the flow.the rad will heat up. The other is the return if it is closed then the hot water will cool in the rad make sure it is open. You may need to remove the plastic cap and use a spanner or pliers to do this.

 

[eggy1970]

Ok lads 4 out of five are now working fine and the last one is the one nearest the boiler.
I switched the heating off then opened up the left hand top bleed and took aprrox 6 pints of water the i opened up the right hand bleed and bled the same 6 pints. i then put heating back on and it is still cold,,,,please help

 

[breezer]

how do you know it was six pints? the valves you refer to are NOT bleed valves, they should both be open.

this is a picture of an invisible radiator (when its empty) but the two valves you can see are the valves you should be adjusting. (the right valve is a trv, which you may or may not have) but you will have a valve

the bleed valve is much smaller and square and probably at the top right hand side

 

[eggy1970]

ok breezer, these valves have been open. Now i switch off the heating then open the top bleed until i get a steady flow of water, then close in this bleed, then switch the heating on,,,,is this correct ?

 

[breezer]

yes.

so i read you may need to balance the system, you could also try turning off all the other rads and see does this one get hot. as i am not a plumber or heating engineer, try a search on balancing

 

[eggy1970]

Ok now i closed in all the other trv;s then turned the heating off then i opened the bleed and took approx 6 pints out of the bleed( i bled into a pint pot) the feed line got hot and the rad started to get hot, i assume this is just hot water in the system. i then turned the heating back on and no joy,still cold rad,

 

[breezer]

if it gets hot when you bleed it but cools down after wards, water can not be flowing through rad, (it gets hot because you are letting water flow by bleeding) either trv is "stuck shut" or blockage in pipe