Help please! One radiator not working on combi boiler system

[milkmaid1510]

Hello -

Please can you help? I'm not familiar with radiators are all and don't do much DIY so please bear with me...

I have a combi boiler and radiators that are all relatively new (4 years old). All my radiators are working fine EXCEPT one big one in the top bedroom. The top bedroom gets quite cold so I really need the radiator to work!

The combi boiler is at the top of the house close to the radiator that isn't working properly. There is a towel radiator in the wetroom next to the big radiator in the top room and the towel radiator works fine and is blasting out heat.

The radiator that isn't working properly has a thermostatic valve on it. We've tried bleeding it but a stream of water comes out immediately. The radiator is set on the highest level 5 but it is VERY patchy and doesn't heat up very well in the areas of the radiator that do warm up a bit.

The pipe that flows into the radiator is hot to the touch but the pipe that flows out is cold.

Is it a balancing problem? And if so, how can I fix it easily?

Can I adjust the little valve (or is it a valve??) that is on the out flow pipe of the radiator?

Your help is much appreciated as my parents are currently visiting and staying in the top room and are FREEZING!

Many thanks in advance!

 

[tam22]

wouldn't have thought it would be balancing as it is close to the boiler and would normally heat up first................maybe a faultly valve (TRV)....experts???

 

[PlumbBobBob]

which valve is on the pipe that gets hot?

 

[boilerman52]

Check the pressure gauge on the boiler, the system may be low on water and require topping up. check for air in the radiator and then top up boiler to between 1and 1.5bar.

 

[Hardy1]

check the flow pipe beetween the pipe and the valve?- if its cold you got an airlock in the pipework, if the flow pipework is hot and the valve is hot(warmish) you got a faulty valve(most likely the pin on the TRV is sticking), loosen the pin or change the TRV.

 

[milkmaid1510]

Many thanks everyone.

The thermostatic valve is on the hot pipe...

Sorry, but what does it mean if the TRV is sticking? Is it easy for me to fix myself? Can I change the TRV myself or do I need a plumber?

Thank you!

 

[dontknowitall]

Take off top, push pin in and relax. Then again and if it starts moving and warm water starts coming through, job's a goodun.

 

[fuzzy]

check valaves and especially trvs as said before

 

[PlumbBobBob]

if the pin is stuck bang the valve firmly but not too hard to see if that frees it up

 

[peter wilson]

the little valve you refer to is the lock shield vavle, yes you can ajust it make sure it is fully open. That may sound a bit obvious ?

 

[WHPES]

If the pin is stuck, tap it a few times to hopefully free it. NEVER try to pull it out or you may pull it out too far and get hot dirty water everywhere.

 

[jncalderc]

Its a combi, drain it change the valves and repressurise

 

[jncalderc]

you will rarely hit a balancing problem with a combi boiler as it is under pressure

 

[jase158]

you will rarely hit a balancing problem with a combi boiler as it is under pressure

have to argue this one, combi's are usually worst for it, in my experience.

 

[jase158]

Many thanks everyone.

The thermostatic valve is on the hot pipe...

Sorry, but what does it mean if the TRV is sticking? Is it easy for me to fix myself? Can I change the TRV myself or do I need a plumber?

Thank you!

Just wanted to add, the pin is underneath the TRV head, to get this off there is a circle underneath, this is usually silver/ grey and needs to be turned anti clockwise.

 

[jncalderc]

Pants, a gravity sytem has nothing but gravity to rely on, air locks all the time, you never get air locks on a combi that young! my opionion only

 

[jase158]

Pants, a gravity sytem has nothing but gravity to rely on, air locks all the time, you never get air locks on a combi that young! my opionion only

hmmm once again have to beg to differ, this is my opinion maybe other people can elaberate more, but doesn't matter what sort of system, what age, what way it is piped, i.e. all systems prone to air locks and balancing problems.

 

[jncalderc]

ok, I bow to your experience

 

[FlowthenReturn]

ok, the rad has 2 valves, make sure they are both open. It sounds like you have 2 rads in the mix here so make sure the valves are fully open on both. If you have the thermo valves remove the top (clip off part) and make sure the pin pushes in and comes up on its own (tap with rubber mallet will usualy sort this if stuck). As per bolierman52 said, check system pressure (gauge on boiler and usualy a fill valve) should be @ 1.5-2 bar cold. bleed all the rads not just the ones upstairs as an airlock elsewhere could be the problem, then check pressure again, if not still the same, repeat.
Hope this helps