Noise from a Vaillant combi boiler (ecoTEC plus 835)

[Misami]

In June, the boiler showed an F20 safety switch off temperature limiter, sign.
We had the Vaillant engineer come out, who told us that the water pressure was the problem.We were also told the TRV4 on our radiators are not suitable for our boiler. Something about a bypass. The heat needs to go somewhere as there's too much of it hence the sound. He advised us to not use one of our radiators which we stopped using. Now we have the same problem again, where the radiator makes the high pitched squealing.

Any help appreciated.

 

[Doggit]

Do you have TRV's on all the rads, and is there a roomstat somewhere.

 

[Misami]

Do you have TRV's on all the rads, and is there a roomstat somewhere.

Yes, all our radiators have the TRV4s. A roomstat? is that the little handheld device to change the temperatures? We have a Drayton Digistat +3RF. Sorry, I am not very technical, it took me 30 mins to realise how to post on here.

 

[Doggit]

You shouldn't have a TRV on the room with the stat, so take the head off the rad in that room, which is what I suspect he really meant. The TRVs will shut the rads down when they are all up to temperature, and that stops the water going anywhere, hence the noise. If the room with the stat has no TRV on it, then the water can keep flowing until the stat switched the boiler off. I suspect you need to balance the rads so they all come up to temperature at the same time, and if you still get the problem, then you'd fit a bypass valve across the flow and return pipes near the boiler.

 

[Misami]

We have the wireless system in the kitchen where there are no radiators. Is that the stat you were talking about?
The other one can be taken to any room in the house. We do have a radiator in the breakfast room which is connected to the kitchen.

Thank You for all your help.

 

[Misami]

The stat in the kitchen which is attached to the wall.

View attachment 133336

 

[Misami]

 

[Doggit]

The box in the kitchen by the boiler, is the receiver, but the room stat should be in the living room, and that rad shouldn't have a TRV on it. By moving it around, you cause a problem because the boiler will keep pumping the water round, and there's no rad to act as a bypass valve.

 

[picasso]

Its nothing to do with the stat, you need to remove one of the trv heads to allow water to flow round at least one of the rads.

 

[Misami]

The box in the kitchen by the boiler, is the receiver, but the room stat should be in the living room, and that rad shouldn't have a TRV on it. By moving it around, you cause a problem because the boiler will keep pumping the water round, and there's no rad to act as a bypass valve.

So this is the room stat which we should leave in the living room?

We use it turn the radiators on and off. The only thing is we use the trv on the radiators to indicate how warm we want it to be. If we take the trv dial off, how do we control the heat? Would you advise us to get a new dial or a new radiator for all the rooms?

I did ask the engineer all these questions before but he was in a hurry to leave for another job.

 

[Misami]

Its nothing to do with the stat, you need to remove one of the trv heads to allow water to flow round at least one of the rads.

Evening, we have taken the trv dial off one of our radiator in June when the engineer advised us to. It’s just the problem is persisting again. The other thing is, one of the dial in the upstairs bedroom just flew off by itself so now there’s two radiator with no trvs

 

[Doggit]

Okay, so you use the stat to turn the system on and off, but it's also measuring the temperature of the room, and it will tell the boiler to stop heating the water in the pipes when the room is warm enough; in your case, that's not happening, and the boilers still running, and because the TRVs have turned every rad off, the water can't go anywhere, so is making a noise.

Did you take the TRV head off of the rad in the room with the stat. Use something to push down the little pin where the TRV head was, and make sure it's not stuck. You can put the TRV head back on the one that fell off; just put it back on, and then turn the ring underneath till it grips and tightens. If the TRV is off in the living room where the stat is, then things should work okay, but if they don't then there's another issue somewhere.

 

[ChrisNason]

The Room Stat should be in one room and that same room should not have a TRV. You need it this way so that the room stat can sense the rise in temperature and turn the boiler off. If you put the room stat in a room with a TRV the TRV will turn that radiator off and the room stat will still be telling the boiler to keep going. (The room that the TRV has fallen off is easy to fix. They just have a screw collar to attach to the valve)

 

[Misami]

Okay, so you use the stat to turn the system on and off, but it's also measuring the temperature of the room, and it will tell the boiler to stop heating the water in the pipes when the room is warm enough; in your case, that's not happening, and the boilers still running, and because the TRVs have turned every rad off, the water can't go anywhere, so is making a noise.

Did you take the TRV head off of the rad in the room with the stat. Use something to push down the little pin where the TRV head was, and make sure it's not stuck. You can put the TRV head back on the one that fell off; just put it back on, and then turn the ring underneath till it grips and tightens. If the TRV is off in the living room where the stat is, then things should work okay, but if they don't then there's another issue somewhere.

I see. I’ll leave this stat in the living room from now on

No we were told to take the trv off from the hallway radiator so that’s what we did. I’ll take the trv off from the living room, we have two radiators in the living room though. I’ll take it off from the bigger one and replace the hallway one with it.

There isn’t any other way to get pass this problem without taking any of the trvs off the radiators?


Many thanks.

 

[Misami]

The Room Stat should be in one room and that same room should not have a TRV. You need it this way so that the room stat can sense the rise in temperature and turn the boiler off. If you put the room stat in a room with a TRV the TRV will turn that radiator off and the room stat will still be telling the boiler to keep going. (The room that the TRV has fallen off is easy to fix. They just have a screw collar to attach to the valve)

Can we leave the room stat in the hallway then? Or would you advise it to be in the living room.