Some radiators not heating up after refill - Please help!

[gutshotkid]

Hi,
I have a 15kw Gloworm boiler (not combi) and I drained down to put a new radiator into a garage conversion. I have refilled the system but the upstairs bathroom, kitchen, and new rad in the garage are not heating up the other 3 rads are fine.
No radiators are letting any air out now.

Any ideas anyone??

Thanks in advance.

 

[seco services]

are they on the same section of pipework ?
probably just airlocked.

 

[gutshotkid]

Hi,

Thanks for your quick reply.

Yes, they are on the same section of pipework, if I had piped the flow and return the wrong way round on the new rad would that be the cause?

If it is airlocked whats the best way of resolving that?

I really appreciate your help.

 

[seco services]

shut the working rads down and turn the pump to max speed.
and only have heating calling for heat.
don't matter what way flow return are on the rad.

 

[gutshotkid]

Great, thanks.

Can I turn them just off at the TRV or do i need to close the lockshield as well?

 

[dlhagan]

Great, thanks.

Can I turn them just off at the TRV or do i need to close the lockshield as well?

do you have cast iron old fashioned radiators or newer slat finned copper tubing?

 

[gutshotkid]

Hi,

They are the newer copper style.

 

[Hugh Jaleak]

The Rads will be steel, copper would cost a fortune!!!

Try turning off the TRV's (its easier!), on all the rads that are working. Pump to max. This should force all the effort from the pump into the rads that arent working, may hear a glugging noise as any trapped air is shifted. Once they are getting hot, turn others back on, pump back to original setting and see if that cures it.

 

[gutshotkid]

Perfect guys, thanks a lot!!!!!

Now that the new rad in the garage is warmig up I have noticed that I have placed the TRV on the return, not a massive problem because I have put isolation valves in the 15mm uprights to the rad but I have noticed that is not that warm at the bottom of the rad - is this because I have put the wrong valves on??

Thanks for all your help.

 

[Hugh Jaleak]

Some of the newer TRV's are bi directional, can go either way round. Check for an arrow, if its a one way valve, then the water needs to flow in the direction of the arrow.

 

[ThatsNotPlumb]

Perfect guys, thanks a lot!!!!!

Now that the new rad in the garage is warmig up I have noticed that I have placed the TRV on the return, not a massive problem because I have put isolation valves in the 15mm uprights to the rad but I have noticed that is not that warm at the bottom of the rad - is this because I have put the wrong valves on??

Thanks for all your help.

If you feel the pipe going into the return side of the radiator, is it roughly the same temperature as the coolest part of the radiator?
If so its usually an indication that the system isn't just 100% correctly balanced.

Could be either that or when you've refilled the system perhaps you've pushed some sludge/sediment into your new radiator.. although that is less likely. Try feeling pipe/coolest part of rad first though & comparing temperature, if they are similar you just need to rebalence the system.

Also I see some people suggested you turn pump up to blow air through. don't forget to turn your pump back to its original speed setting (unless of course you need to keep it turned up for the waterflow to be substantial where your new radiator is..)

Let me know how you get on