running hot water heats up radiator!

[drgl]

Vaillant combi boiler,when drwaing hot water ONE of the upstairs radiators also gets warm!! I've only just noticed this but i'm 99% sure it didn't always do it! Is this likely to be a diverter valve problem?? Will it cause any damage to the boiler?? Thanks in advance.......

 

[ollski]

yes the diverter valve is passing.....which model is it?

 

[drgl]

Turbomax 242E,will this cause damage??

 

[Igorian]

No, but you may find your domestic hot water is not as hot as it should be because you will be losing heat by convection to the rads. It could be the valve is stuck or the actuator (the motorised part of the valve) is u/s. I replaced the actuator on my Potterton Statesman and the part cost about £90. I think the complete valve was about £170

 

[drgl]

Thanks for the info,the DHW is still VERY hot(!) so i'll leave it until things get worse i think,it's strange how only ONE radiator gets warm though???

 

[namsag]

If this is closest rad to boiler you may have no problem at all . With everything cold start filling the bath as you would normally do. Then go and feel pipes to rad and see if they are getting warm. If they are you have a faulty divertor . If they are not getting warm let bath fill then turn hot tap off and go and feel pipes now , if they start to warm up now it is because the boiler is dumping heat round this radiator (on over run) as a bypass and is quite normal .

 

[ChrisR]

Igorian - the turbomax 242 doesn't have a motorised diverter.

 

[drgl]

namsag,i think you've hit the nail the the head!! This is the case,the radiator is only warm after running the hot tap for a while,it doesn't get warm when running a bath,thanks very much for the info