1 radiator wont get hot!!!

[AIRCOOLED 72]

Last year i had a new jaguar combi boiler fitted using existing radiators.
I also had thermostats fitted to the rads except the one in the hall
wich would be hot all the time ( thats what the guy told me anyway)
at first all was well, then the rad in the hall would not work unless the heating had been on for a while.
Now it doesant work at all, I have drained the system and fitted new valves as the origanal ones were still fitted , the hot water is flowing through the pipe to one end of the rad but no further, when i bleed the rad it starts to get hot but then cools down .
can anyone help with any ideas im getting frustrated now (and chilly)

 

[breezer]

i am not a plumber or heating engineer, but i would like to ask. have you made sure both valves are open.

I am thinking that by bleeding the rad you are letting water flow from the "in" Pipe out through the bleed valve so rad gets warm. when finished bleeding no more flow.

so i am thinking the "out" valve is shut (or stuck shut / blocked)

 

[AIRCOOLED 72]

part of the reason of new valves was to check they were open (they are)
I wondered about a air lock in the pipe going upstairs but don't know how to check or cure?

 

[masona]

Have you try bleeding air from the pump when not running ?

 

[Plumber Will]

Try feeling the pipes one should get hot first (the flow) the other is the return if it does not get hot then the rad must have sludge or another restriction in the rad if it gets hot then cools then the return is blocked further along the return. Are they minibore or 15mm pipe.

 

[AIRCOOLED 72]

yes they are 15mm pipes.
The flow does get hot but the return does not.
There is a drain bung ater the return,if i drain off the return pipe the rad gets hot but cools down later . so it does sound like a blocked pipe but i can blow down it (when drained) and its clear.

 

[masona]

Ignore my last post ,I've forgot you got a combi.

Is this the only radiator not working ? if so could be a blockage round the drain bung area.

 

[AIRCOOLED 72]

the rad in the dining room takes a long time to heat up and sometimes not at all bizarrely enough
where is the drain bung

 

[AIRCOOLED 72]

some one has just told me the rads might need ballancing
is this correct
how do i do it
the valves are fully open at the moment!

 

[masona]

You could try shutting all radiators expect for the hall radiator and see what happen.The radiator don't normally need balancing if you've got TVR's.

 

[AIRCOOLED 72]

Big thanks to all of you.
I tried masona's sugestion switched off all rads except one and it seems to have worked
it seems to have shifted the air lock
one last question :where is the air now ive bled the rads again and got no air.

 

[miah]

You could try shutting all radiators expect for the hall radiator and see what happen.The radiator don't normally need balancing if you've got TVR's.

Hi Masona,

When you say shutting all radiators and than try, you mean switching the heating on? and see what happens. Correct?

I'm just thinking If I experience a similar problem like this I can make a note from this for future reference.

I'm getting some new radiators install very soon, however there are some existing ones which will be left on and they don't have TVR's on them but new ones comes with TVR on them.

I was wondering shall I get the old RAD TVR's install on them?

And lastly, I know it is best practise to install RAD near the window so that clod air mix with hot air etc.... as for bay windows its quit expensive to have the RAD curved, so I was thinking can we install the RAD any other place apart from the window?

Many Thanks

 

[masona]

Big thanks to all of you.
I tried masona's sugestion switched off all rads except one and it seems to have worked
it seems to have shifted the air lock
one last question :where is the air now ive bled the rads again and got no air.

You probably didn't have air-lock in the system but sludges build-up which restricted your flow.Might be a idea to drain the system down and add inhibitor.

 

[masona]

When you say shutting all radiators and than try, you mean switching the heating on? and see what happens. Correct?

Yes.

I'm just thinking If I experience a similar problem like this I can make a note from this for future reference.

Nothing can stop you trying these thing but the problems could be something else.

I'm getting some new radiators install very soon, however there are some existing ones which will be left on and they don't have TVR's on them but new ones comes with TVR on them. I was wondering shall I get the old RAD TVR's install on them?

If they are in good working order,I cannot see why not.

And lastly, I know it is best practise to install RAD near the window so that clod air mix with hot air etc.... as for bay windows its quit expensive to have the RAD curved, so I was thinking can we install the RAD any other place apart from the window?

There is no regulation where you want to put radiator,the choice is yours.