Brand new noisy boiler

[Mike13]

Hi, as title,

Brand new Vaillant ecotec 30 feeding 13 rads, 5 without a TRV, 3 of the rads are brand new.
Either I can have the system so unbalanced that a few are too hot to touch and 3-5 of them stay stone cold and we have cool/cold rooms or whenever I slowly bring it back to balance it starts a loud whine/hammering noise that stops when fiddling with the rads and it ends up unbalanced again.
By adjusting the balance the cold and hots rads can by moved from any to any, not found the problem sticking with any single rad.

The system was previously on another old vaillant, but extension meant it needed to be moved, so was changed at that time. the previous vaillant was fussy about how clean the system was and new one has a mag trap fitted too.

Plumber has not helped enough yet, keeps not hearing the noise.

Any tips??

 

[durhamplumber]

Plumber has not helped enough yet, keeps not hearing the noise.

?

 

[Mike13]

Unfortunately each time he came round it was out of balance and quiet, not a deliberate error.

 

[Mike13]

Ok, even stranger, this evening I have ALL the new rads with their TVR's set to MAX, and it is still clicking/buzzing, the note changes and sometimes briefly dissappears, but does not stay away. Two of the new rads are too hot to touch, the third one remains lukewarm, so not much backpressure from all the rads, stumped. Cannot believe that all 10 old rads have suddenly gone bad at the same time!

 

[Mottie]

Could it be the pump? Is it running too slow? Just guessing by the way - I had to piddle about balancing, adjusting pump and bypass settings when I had a new boiler fitted to get things spot on.

 

[Mike13]

I could not see any settings to change the pump. And the plumber has not mentioned anything about selecting a different speed.

 

[Mottie]

My pump is separate from the boiler but if yours is built in, maybe it’s a variable speed one and if it’s a combi I doubt if you’ll have a separate by-pass either. Sorry I couldn’t be of more help - that’s the limit of my knowledge and it worked for me on my system which sounds like it’s different from yours.

 

[dilalio]

Was the system flushed during the swap?

 

[Mike13]

Yes, the plumber told me he flushed it, added some cleaner for a few days, cleaned drained and refilled. the trap is catching a little bit of magnetite, but it was not a lot.

 

[ianmcd]

you say that you are balancing the system, how exactly are you doing this, definitely sounds like a balancing problem and you boiler setting for CH is far too high

 

[Madrab]

Is it clicking/clunking at the radiators or at the boiler? Why are some radiators without TRV's? Are the TRV's fitted correctly, check if they are bi directional?

You mention that the plumber (why was a plumber replacing a boiler, or is he actually a heating engineer?) cannot hear it but surely if the system is out of balance and it's quiet but some rads aren't heating up, then that alone should be getting him to look at the system again, regardless of whether it's making noise or not.

 

[Mike13]

The Plumber is a qualified installer, the original Vaillant, while working, was old and in a location that was to be used for a different purpose. Moving it might have worked, but we were also needing new radiators fitting anyway. I bought the house ~20 years ago with the boiler in and working. At that time it already had 9 radiators, and 5 of them had TRV's. I later added two more radiators without TRV's and was able to get and keep them balanced.

The plumber relocated the boiler with a brand new Vaillant ecotec 30 and added the three new radiators, all with TRV's.
Downstairs we have 9 radiators, 5 with TRV's as well as the boiler being downstairs. Upstairs we have 4 radiators, 3 with TRV's.

I currently have the three new radiators set quite high, one of them on Max. the one set to max seems to stay cold with very occasional lukewarm. It still makes occasional noises. If I close any of the others down a little so that the too hot to touch radiators stay a little cooler then it gets much too noisy.

I use a 1/4 spanner on the "fixed" end to slowly close it down a few degrees at a time and use the tap end to open close when trying to work out which valve? if any is causing the noises.

 

[Madrab]

Are the TRV's a installed correctly? Definitely sounds like something is causing resistance at certain points in the system and isn't allowing it to be balanced properly. Without knowing the system and how it's piped then it's hard to know if it's how the system is laid out now or if it's a specific system component that's causing the issue.

If you shut down the three new radiators, does it settle down?

 

[Mottie]

Years ago in our first house, I fitted a TRV to a rad and put it on the wrong side. Christ, did it make a racket!

 

[Mike13]

well they were working before the new boiler was fitted, no radiator noises ever. I would presume that the plumber would keep the out and return the same as before, but I guess I shoulfd ask that specific question/