HELP: Vailiant System Boiler LOUD Vibrating Sound Whenever Upstairs Heating Is On

[Gsandhu2024]

Have you tried turning all the TRV’s off together and then seeing if the sound still happens?

Hi

I will try this tonight

 

[Gsandhu2024]

Maybe turn them all full on first, ie, open them fully, the start shutting them down?

Hi John

Iv got them all fully open to max setting. The issue I have is the moment I will go to turn any of them off the sound is already gone at that point. The sound literally occurs at the point of switching on the heating for like 5-10 seconds if that.

Thats why i was thinking do i switch them all off first then switch off the heating, let it cool, gradually open one up and switch heating back on…

 

[Johntheo5]

If the UFH is already on, does the same thing happen?
Is the boiler pressure 1.0 to 1.5bar when cold?.

Also just set the ABV to say index 0.1 briefly on start up.

 

[Gsandhu2024]

Hi John, it never used to do it when the UFH is on but has now started to do it but its less loud if the UFH is on if that makes sense?

Boiler pressure is fine sits around 1.4 then goes to like 1.8 when heating is on

 

[Johntheo5]

Just try that ABV setting for a few minutes.
Also look at the motorized zone valve for the upstairs heating and ensure its pointing in the right direction.

 

[DP]

Is the boiler making a banging noise or is it a foghorn noise.
With all TRVs open, it is not a circulation restriction ( caused by radiator TRV closing)
If the noise occurs at startup, then doubt will be TRV issue.

 

[Johntheo5]

It sound to me initially like something in the boiler and thats why I suggested opening the ABV almost fully to index 0.1, if no banging then perhapd something to do with that internal bypass, if the ABV is then shut rapidly to 0.6 and banging restarts then points possibly to the internal bypass?.

 

[Gsandhu2024]

Just try that ABV setting for a few minutes.
Also look at the motorized zone valve for the upstairs heating and ensure its pointing in the right direction.

Hi I changed it to 0.1 and it still made the noise.

What do you mean about pointing in the right direction please?

 

[Gsandhu2024]

Is the boiler making a banging noise or is it a foghorn noise.
With all TRVs open, it is not a circulation restriction ( caused by radiator TRV closing)
If the noise occurs at startup, then doubt will be TRV issue.

Hi DP it literally makes a huge foghorn noise which then rattles the floorboards the video is here:

This now occurs each time I put it on regardless of UFH being on whereas last year it wouldn’t make the noise when UFH was on

 

[Gsandhu2024]

Hi I changed it to 0.1 and it still made the noise.

What do you mean about pointing in the right direction please?

The top one is the motorised valve for the upstairs heating…

 

[Johntheo5]

The arrow on the valve body must point towards the rads or cylinder heating coil.

 

[Gsandhu2024]

The arrow on the valve body must point towards the rads or cylinder heating coil.

Do you mean the motorised valve near my boiler or the TRV on my radiator?

 

[Gsandhu2024]

The arrow on the valve body must point towards the rads or cylinder heating coil.

Sorry john I don’t quite understand. Iv attached a picture of one of the trvs and the actual motorised valve on my boiler

 

[Johntheo5]

The ones that have motorized valve written on them, if the rads are above that valve shown above then the arrow on the valve body must point upward. (I think it is judging by the wiring).

 

[Gsandhu2024]

I’m sorry I can’t quite understand and can’t see any arrows? All I know is the highest motorised valve is for the upstairs heating.