COLD RAD

[smith6]

I HAVE A RAD IN SHOWER ROOM THAT IS ALWAYS COLD. I CAN GET SOME WARMTH IF I INCREASE THE TRV SETTING IN BEDROOM NEXT DOOR. FEED PIPE (TO LSV) IS HOT BUT TRV (RETURN SIDE) IS COLD. HAVE FULLY OPENED LSV & TRV. TRV PIN IS NOT STUCK. I THINK THE SHOWER ROOM IS SPARRED OFF OF THE BEDROOM PIPES. ANY IDEAS?

 

[Blasphemous]

How long have you had it fitted? Is it newish? The TRV might NOT be Bi-Directional and as such it should be on the Flow not the Return.

edit.

 

[Strachan]

First of all, is it a new rad,and did it ever get warm?

 

[smith6]

RAD is about 6 years old and it is in an extnesion so was added to my system. It has worked previously but never really been independent. Recently though no heat hardly at all.

 

[Strachan]

Have you tried strangling down the other rads slightly?

 

[smith6]

Do you mean turning LSV anti-clokwise, then no. Is it worth a try and if so what would you recomend as "slightly" - how many turns?

BTW the cold rad is closer to the boiler than the bedroom rad.

thanks for your promt response.

 

[Strachan]

A couple of turns on each. The rad may be nearer the boiler than the bedroom one, but is it piped as such?

 

[smith6]

pipes are not visible but it might be possible that there are longer runs. I'll try it tomorrow and let you know. cheers for now.

 

[smith6]

reduced flow on bedroom rad but had no affect. should i reduce flow on all other rads or try something else? BTW the TRV's are bi-directional (they have arrows pointing both ways on valve body) I think.

 

[JohnD]

Reduce the flow on all the others so that the water is encouraged to flow through the cool one.

Consider a chemical clean, flush and refill with inhibitor as there may be black sediment clogging it if it has got worse over time.

Have a look at the plumbing FAQs and Wiki and look at balancing and flushing.

Make sure both the valves on the cool rad are fully open and not sticking.

You may need to take up the floor and see how it is piped. It may have been added on wrongly, if it has never been good.