banging pipes / thermostatic valve problem

S

snadge

we are having LOTS of problems with our CH... the newest problem (no.4) is banging pipes/valves after heating has been on for a while - annoying, sounds like someone is hammer drilling upstairs... ive since found that it is radiator thermo valves in different rooms... first was the little box room - it was on 5 (full) i just turned it down then it stopped and put it back to 5 and it was OK again... its done it once or twice more since then so i have disabled the rad completely by turning the thermo valve to its lowest frost setting and turning off the opposite valve...

the same thing happened other day and it was the one in main bedroom which I had on 1.5 (these things go * - 1 - 2 - 3 - 4 -5) - I turned it to 5 and it stopped banging...

now tonight it started again, this time it was the bathroom radiator valve.. it also was on 1.5-2 , i turned to full and the banging stopped...

how do these valves work and why do they bang, what does it mean?

thanks
 
Sponsored Links
Joined
8 Jan 2005
Messages
19,003
Reaction score
1,568
Location
Bath
Country
United Kingdom
If it's the TRV, then they are on the return and not the flow.

Take the actuator (head) off and it will stop until you get around to swapping them over.
 
S

snadge

thanks

how do you know if they are on the wrong end for sure?

im amazed because we moved into this house 6 months ago and previous owner said that the new boiler etc was installed 2 years previous...im assuming she had the rads and valves put on too... now your telling me that the plumber/company who's done it has but the TRV's on the wrong ends?

weve only ever had them on 5, this is our first winter and as its been really cold i decide to restrict and turn off some of the rads... as soon as ive done this its started banging now and again...resulting in me having to run upstairs and start messing around with the TRV thats causing it...


it only happens if i restrict them... on 5 (full) seems to be OK most the time, just once or twice in little room theyve gone off (banging)
 
Joined
8 Jan 2005
Messages
19,003
Reaction score
1,568
Location
Bath
Country
United Kingdom
Because I do. ;)

It the pressure differential when they start to close, exceeds the manufacturers specification.:cool:

Feel the pipes the return end will be the hottest.

If you have a by-pass in the system, you could open it a bit more and it will improve it.
 
Sponsored Links
Joined
26 Oct 2004
Messages
5,232
Reaction score
469
Location
Surrey
Country
United Kingdom
now your telling me that the plumber/company who's done it has but the TRV's on the wrong ends?

That is the length and breadth of it. I expect your previous owner got 5 quotes and since 'all Gas Safe heating engineers are the same' went for the most economical.

As it turned out, it was the most economical for them, because you are the one who is going to have to shell out for the remedial work.

Unless they only sold the house to get away from the banging noises in winter :eek:
 
S

snadge

Because I do. ;)

It the pressure differential when they start to close, exceeds the manufacturers specification.:cool:

Feel the pipes the return end will be the hottest.

ok... i believe you :)

feel the pipes... when i have them OFF or ON..?

if i have had the CH off and all pipes/rads are cold and then turn on the CH then check, yes? -

How will the return be the hottest? I would have thought it be the feed as thats the one pumping the water in so gets hot first...?


thanks again - im just gunna stick ones ON to 5 and others OFF at both valves until we can sort it...
 
Joined
8 Jan 2005
Messages
19,003
Reaction score
1,568
Location
Bath
Country
United Kingdom
If the rads are cold turn the heating on, and feel the pipes the TRV end should get hot first.

You can probably tell with it on now, as the TRV end should always be hotter.

All you need to do is either close the TRV or take the head off.
 
S

snadge

aye your right :) - one next too me here on laptop (downstairs) the TRV pipe feed is too hot too touch but the opposite is hot enough to touch... im gunna have my tea now and will check them later and report back on my findings..

thanks for your speedy help and advice.. :)
 
Joined
8 Jan 2005
Messages
19,003
Reaction score
1,568
Location
Bath
Country
United Kingdom
Where the TRV end is the hottest it is the correct way round.
 
Joined
8 Jan 2005
Messages
19,003
Reaction score
1,568
Location
Bath
Country
United Kingdom
i started celebrations about mid day. :LOL:

On the bushmill single malt whiskey now.

I feel a bad head coming on in the morning. :p
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Top