Noisy radiators
- Thread starter SinkLayer
- Start date
Sponsored Links
Searching for some info on auto by-pass valves and found this old post...
I've just got a new S-Plan CH system up and running and while it seems to all be working OK, I had some rad noise. Initially I had yet to balance the rads, but upon closing down a couple to only half-turn, the noise disappeared. Now I do have one thing that seems a bit odd, the Honeywell (DU145) by-pass valve is wound to position 6, which I assume to be the highest setting and therefore no by-pass, but the pipe from the valve back to the boiler remains hot?
Could someone please explain what might be happening here and / or elaborate on the above mentioned older post?
Many thanks.
I've just got a new S-Plan CH system up and running and while it seems to all be working OK, I had some rad noise. Initially I had yet to balance the rads, but upon closing down a couple to only half-turn, the noise disappeared. Now I do have one thing that seems a bit odd, the Honeywell (DU145) by-pass valve is wound to position 6, which I assume to be the highest setting and therefore no by-pass, but the pipe from the valve back to the boiler remains hot?
Could someone please explain what might be happening here and / or elaborate on the above mentioned older post?
Many thanks.
Sponsored Links
Trv is fitted on wrong pipe. The noise is the TRV vibrating as it closes.
Older valves (and some so called reversible ones) must be fitted on the flow.
Feel the pipes when you turn the heat on. The water should be flowing in the direction of the arrow on the valve i.e. if the pipe the valve is on heats first the arrow should be pointing into the radiator.
If the valve has 1/2" nuts on both sides drain the system and turn it around. (if the head is pointing upwards turn it so it is pointing sideways).
Older valves (and some so called reversible ones) must be fitted on the flow.
Feel the pipes when you turn the heat on. The water should be flowing in the direction of the arrow on the valve i.e. if the pipe the valve is on heats first the arrow should be pointing into the radiator.
If the valve has 1/2" nuts on both sides drain the system and turn it around. (if the head is pointing upwards turn it so it is pointing sideways).
The above answer was for the question posted 4 years ago. 
The above answer was for the question posted 4 years ago.
That was the original question and the SP has the same problem.
Doitall i only read the first bit and answered. That will teach me to read a bit more
Doitall i only read the first bit and answered. That will teach me to read a bit more
We've all got that T shirt.
Doitall i only read the first bit and answered. That will teach me to read a bit more
We've all got that T shirt.
err yeah
like is it thermostatic ?
Many thanks for the reply, but I fear I'm still being a bit dumb.... are you saying position 6 is fully open (turned fully clockwise) – i.e. full by-pass flow, and 1 is fully closed?
The numbers refer to "Differential Pressure" 0.1 - 0.6.
If the valve isn't shutting off with the system fully open, then the pump speed is too great, turn it down, the pump is too big, or the valve is faulty or dirty, could be a bit of grit stopping it for example.
If the valve isn't shutting off with the system fully open, then the pump speed is too great, turn it down, the pump is too big, or the valve is faulty or dirty, could be a bit of grit stopping it for example.
Did as you suggested, but still no difference between position 1 and 6, by-pass return feels just as hot as flow.
Did suspect pump might be too big at the moment (Grundfos 15-60), even though it's only a bungalow was advised to go with the bigger pump as will soon be starting a large extension. However at the moment it's only running HW cyl and 5 rads. So, was originally on speed 2, now turned down to 1... and again no difference with by-pass valve - return pipe always hot
For info, all components are brand new, inc TRVs which are installed on flow side and in correct direction.
Thanks!
Did suspect pump might be too big at the moment (Grundfos 15-60), even though it's only a bungalow was advised to go with the bigger pump as will soon be starting a large extension. However at the moment it's only running HW cyl and 5 rads. So, was originally on speed 2, now turned down to 1... and again no difference with by-pass valve - return pipe always hot
For info, all components are brand new, inc TRVs which are installed on flow side and in correct direction.
Thanks!
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
