Noise from a Vaillant combi boiler (ecoTEC plus 835)

[Terry lambert]

The hallway is traditionally where you would put your room stat as it is the draftiest, dont put the room stat too close to the rad,

 

[Misami]

The hallway is traditionally where you would put your room stat as it is the draftiest, dont put the room stat too close to the rad,

Ah, that’s probably why the engineer took the trv off the hallway radiator. I’m a complete dummy regarding this. Thank You for all the helpful messages.

 

[Terry lambert]

If he took the TRV off of the radiator in the hall and the noise has returned it would suggest to me that maybe the internal by pass on your boiler could be causing a problem, sometimes adjusting it can cure the problem.

Or

Sometimes it can be as a room starts to come up to temp and the valve is closing it can cause a noise, if you locate it to one radiator try adjusting the setting and if the noise stops, that valve is your problem, moving it to the flow pipe as opposed to return can cure it

 

[Doggit]

The TRV4s should be bi-directional, so won't matter whether they are on the flow or return. There ae a lot of debates as to the stat being in the hallway or the lounge, but it's whichever room that the stat is in that needs one rad without a TRV. In the hallway, if the front door opens, the hallway will get cold, and the boiler will start up, but if the rooms have TRVS, then they shouldn't get any hotter. Personally, I feel the room where you're sitting should have the stat, and the hallway getting a it cold isn't important.

But as Terry has suggested, if there's an automatic bypass valve on the boiler, that may need servicing

 

[ChrisNason]

Most people leave the Room Stat in the hall and that radiator is the one without a TRV.

The hall will be responsible for turning the boiler on and off. All the others will have their temperature controlled by TRVs

 

[ChrisNason]

Ah, that’s probably why the engineer took the trv off the hallway radiator. I’m a complete dummy regarding this. Thank You for all the helpful messages.

Which would have worked fine except you took the Room Stat out of the hall and put it in the living room. So the hall radiator is working overtime because the Room Stat is in a room where the TRV has turned off.

 

[Terry lambert]

@Doggit TRvs although listed as Bi directional they can still have issues installed on the return, like noise in some instances

It is always preferable to install on the flow

 

[Terry lambert]

The reason the stat is traditionally in the hallway is it is normally draftiest

The idea being If you have the stat in your front room and that room comes up to temp quite easily the rest of your house will may well go cold, if installed in the draftiest/coolest part of the house you then control the other areas of your house with TRVs

If the coolest is satisfied then so should the rest of the house be

 

[Misami]

Thank You so much to everyone who took the time to help me out here. Wishing you all a very happy new year.

Very grateful,

Misa

 

[John D v2.0]

That boiler has an auto bypass valve, so it should not matter if all the rads are off as the bypass should open. The F20 code apparently indicates a separate wiring fault, which has presumably cleared.

Regarding the noise issue, if your TRVs can't manage to switch off with the level of flow through them with all the others shut down, the bypass needs to open earlier. Normally that bypass would only ensure minimum flow through the boiler (thanks Terry!) but maybe your TRVs need less flow to close.
Unfortunately your bypass is inside the combustion case, so you'd need a gas safe person to adjust it.
But if turning the valve in the room with the thermostat to max has resolved the problem, leave it at that. If you have further trouble, bear the above in mind.

 

[Terry lambert]

The auto bypasses over time can become noisy on these, an adjustment can cure or replace