Noisy pipes next to thermostatic valves

[dazzler10]

Hello,
We have recently moved into a new house. The central heating / boiler (Baxi 105e combi) is 12 - 18 months old.

Once the heating has been on for a while and the thermostatic valves kick in, the pipes (immediatly near the valves) vibrate very loudly and only stop when the valve is turned up or down slightly? It does this randomly on different radiators?

I have bled all radiators and all seem ok, the pressure on the system also looks ok. (between 1 & 1.5)

Any ideas?
Thanks

 

[cross thread]

the valves have a flow direction on them yours are on the wrong way round

 

[doitall]

the valves have a flow direction on them yours are on the wrong way round

Maybe.

The real problem is the pressure differencial is to high when the valves shut.

Needs an auto by-pass valve fitting

 

[uknokianut]

Your valves are def fitted the wrong way round. But more common is that the boiler has been renewed recently and the flow and return pipes have been connected the wrong way round - thus the water is flowing backwards round the system .

 

[sime10]

the valves have a flow direction on them yours are on the wrong way round

Maybe.

The real problem is the pressure differencial is to high when the valves shut.

Needs an auto by-pass valve fitting

?????????????? Big maybe

 

[doitall]

sime10,

Its unlikely that an 12-18 old system has thermostaic valves that are not bi-directional, agreed they could be.

My theory is, because the boiler has an integral by-pass, that the sysytem exceeds the 125litres and the expansion vessel is too small, therefore when the thermostatic valves close the differencial (honeywell are worse) exceeds the manufacturers limits.

 

[sime10]

Boiler is 12 to 18 months old yes.
valves and rads?

 

[doitall]

Boiler is 12 to 18 months old yes.
valves and rads?

OP said new house so I assumed so

 

[RichardPr]

Yep - the same subject - noisy raidiators! Having spent 6k on an entire new system (we had hot air) we have radiators all over the place making enough noise to raise the dead. The guy who put this in (CORGI registered) since found he spent time at HM leisure as he nearly gassed some one when he installed a boiler incorrectly - thus my guarantee is a no go as we will not have him back! Apart from the pump on the boiler (its in the loft)he put a further pump in downstairs so water circulates like a train. Guess it goes with out saying that I need to get some one in to 'balance' the system. Its a combi system - thermostats on all rads - Potterton. Water pressure here is very very high. Boy, didnt I pick him!!

 

[ChrisR]

Try the pumps on speed 1.
Try closing all the lockshield rads , on the rads near the pump, to just half a turn open. Same for any noisy ones. Excess flow can make trv's noisy.

 

[uknokianut]

Try the pumps on speed 1.
Try closing all the lockshield rads , on the rads near the pump, to just half a turn open. Same for any noisy ones. Excess flow can make trv's noisy.

Dont try the pump on speed no 1 - this boiler is a combi and will need to be set higher as per manufacturers instructions .