Opening upstairs rad reduces noise in downstairs rads !

[swebb99uk]

Hi, a bit of advice required.

I've been getting a lot of fast water flowing sounds from three radiators downstairs but not all and upstairs they are quiet, well most of the time. I've bled the system 3 times and also played around with the locks and balancing the system. I can make small improvements but not much. This system is running on a new Worcester Bosch CDI combi boiler.

Last night I noticed that if I opened two radiators upstairs in a room i usually don't heat the noise in the downstairs rads reduced by about 50%. If I closed the rads back off again using the TRV's the sounds came back. I played around opening these two rads in combination and one in particular makes the difference but I really need both open to make the big difference. Interestingly if I don't open the one which makes the big difference I can hear the gushing water sound in the other.

Why would opening a couple of rads upstairs (and only two in particular) cause the nouse in three rads downstairs to decrease ? I don't undersand how they can have that effect. Opening and closing any other rads upstairs has not effect at all. As far as I remember the pipes that came out of the boiler went in to the kitchen and then branched off two going along under floor to the lounge and feeding the downstairs rads and two staying at kitchen ceiling level going under the bathroom floor and feeing upstairs.

I should add I've been in the house 3yrs and the heating has always been fairly noisy and I recently had an extension fitted and a new CDI boiler fitted with a couple of extra rads downstairs. I had hoped this would have improved the noise but if anything it is worse.


Any idea's ?

Thanks

 

[SJB060685]

What are the size of pipes feeding downstairs rads? Water flowing noise is often due to water flow speed of over 1 to 1.5 m/s. Water moves faster through smaller pipework

 

[swebb99uk]

What are the size of pipes feeding downstairs rads? Water flowing noise is often due to water flow speed of over 1 to 1.5 m/s. Water moves faster through smaller pipework

Hi thanks for the response. Thats actually something I had checked and as far as I can see all pipework is the same large diameter as somebody in the past had updated all of the system, probably in the 90's I should think.

 

[steadyon]

Some cheap TRVs can make the most appalling noises occur in the radiator to which they are attached, or even to others. The noise often disappears by altering the TRV setting by a fraction, but will come back.
What TRVs do you have fitted?

 

[swebb99uk]

Some cheap TRVs can make the most appalling noises occur in the radiator to which they are attached, or even to others. The noise often disappears by altering the TRV setting by a fraction, but will come back.
What TRVs do you have fitted?

I seem to have a bit of a mix, some old and some new, the new ones are Eres ? Not sure about the old ones. I have played around with the trv settings and it doesn't seem to make much difference unless I stop the flow. I even removed the tops on a few to make sure nothing was sticking. The ones upstairs when I fully open to reduce the noise downstair obviously reduce the noise when fully open but the noise comes back when fully closed. It almost seems the wrong way around as to what you would expect to me !

 

[centralheatking]

Hi, a bit of advice required.

I've been getting a lot of fast water flowing sounds from three radiators downstairs but not all and upstairs they are quiet, well most of the time. I've bled the system 3 times and also played around with the locks and balancing the system. I can make small improvements but not much. This system is running on a new Worcester Bosch CDI combi boiler.

Last night I noticed that if I opened two radiators upstairs in a room i usually don't heat the noise in the downstairs rads reduced by about 50%. If I closed the rads back off again using the TRV's the sounds came back. I played around opening these two rads in combination and one in particular makes the difference but I really need both open to make the big difference. Interestingly if I don't open the one which makes the big difference I can hear the gushing water sound in the other.

Why would opening a couple of rads upstairs (and only two in particular) cause the nouse in three rads downstairs to decrease ? I don't undersand how they can have that effect. Opening and closing any other rads upstairs has not effect at all. As far as I remember the pipes that came out of the boiler went in to the kitchen and then branched off two going along under floor to the lounge and feeding the downstairs rads and two staying at kitchen ceiling level going under the bathroom floor and feeing upstairs.

I should add I've been in the house 3yrs and the heating has always been fairly noisy and I recently had an extension fitted and a new CDI boiler fitted with a couple of extra rads downstairs. I had hoped this would have improved the noise but if anything it is worse.


Any idea's ?

Thanks

Its often the case that the TRV valves are on the wrong side because they are not universal, some are
others not, its easy to check but if they are wrong way round they can 'bump back' and the vibration comes out where ever....mastermind now ....centralheatking

 

[swebb99uk]

Its often the case that the TRV valves are on the wrong side because they are not universal, some are
others not, its easy to check but if they are wrong way round they can 'bump back' and the vibration comes out where ever....mastermind now ..centralheatking

Great thanks, how do I check them ?

 

[centralheatking]

Great thanks, how do I check them ?

There might be an arrow indicating the direction of flow to return, hot side to cooler side so when heating starts up feel the pipes either side of the rad and determine which end heats up first. Or you could turn off the valve and see if the bumping ceases as a second method. centralheatking

 

[doitmyself]

Which version of the WB CDi boiler do you have?

How many radiators do you have?

 

[swebb99uk]

Which version of the WB CDi boiler do you have?

How many radiators do you have?

It's the 34 CDI classic ERP and I have 3 vertical rads, 2 towel rails and 6 normal rads, various sizes.

 

[swebb99uk]

There might be an arrow indicating the direction of flow to return, hot side to cooler side so when heating starts up feel the pipes either side of the rad and determine which end heats up first. Or you could turn off the valve and see if the bumping ceases as a second method. centralheatking

Well I had a play around with a few of the rads. What I have found are most have the TRV's set up so that hot water exits via them, however the small rad which is either the first or last rad in the loop upstairs has an arrow indicating the water should exit via it but actually enters via it. This is the rad that when closed causes increased water gushing noise (like fast water under pressure) in some of the downstairs rads. When open the noise reduces a fair but but is still more than you would expect.

I also noticed that my hallway radiator is letting the hot water in via the TRV and there is some writing on the value but it doesn't appear to have an arrow, the text appers to read Covmap or something like that with a strange almost M shapped symbol below it. This rad also suffers from the water gushing sound.