TRVs Turning Radiators Off Too Prematurely

[Gigagator]

Hi all,

My elderly grandmother had a complete new central heating system installed two years ago to replace a (very) old Servowarm system that was on its knees.

As part of this, she had to have a new boiler and complete new pipework and new radiators throughout the entire house so it is a completely new system.

The boiler is an Ideal Logic Max Combi C30 which seems a nice little boiler.

Unfortunately, she has complained with the recent cold weather that she feels cold when sat in her living room and it appears to be because the TRV is shutting the radiator off before the room is comfortably warm enough. The same is happening in her dining room.

The thermostat is a wireless type which is wall mounted in her large hallway.
As an example from the other day, the thermostat clearly showed that the temperature in the hallway was 19 degrees while the target temperature was 26 degrees. The heating was running.

However, the radiators in the living room and dining room were mildly warm as if they had been off for about 20 minutes. That leads me to think the TRVs are knocking them off.

The TRVs are Myson Petite and they are set as high as they will go.

I was wondering if there was anything we could do to temporarily override them or something just until the weather gets warmer so that she is not cold in her home. Or is this something we need to get a professional to sort?

The difficulty is the fella that fitted the system (very trusted engineer, our family have used him for years) is flat out doing contract work for British Gas at the moment and has can't fit us in.

Photos attached for reference, ignore dirty marks on TRV, it is a new system honestly but she is a smoker.

Any advice greatly appreciated as always.

 

[terryplumb]

Take the TRV actuator head off completely and see if rad remains at full heat

 

[denso13]

I was wondering if there was anything we could do to temporarily override them

You could take the heads off, there will be no control but will heat up with no restrictions.

 

[Gigagator]

Thanks for responses both.
Does the head just pull off? That's not going to damage it at all and it can be replaced at a later time?

 

[terryplumb]

Unscrews with the big chrome nut just below the white plastic head . Won't do any harm and can be refitted any time.

 

[ericmark]

Until I fitted electronic TRV heads I did not realise how bad the old mechanical ones were. However in mothers old house all the electronic ones were removed and replaced with the old mechanical ones, and they worked A1.

Over some time if the target was over current I had closed the lock shield valve a little and where target was under current opened it a bit, and it seemed the whole problem was the lock shield valve settings.

But this house the whole problem has been repeated, and I have tried to use my tommee tippee point and read thermometer to set the radiators, but many I can't reach, stuff piled in front of radiators.

Theory is great, 20°C inlet to outlet, but in practice you have to get access to radiators and set the difference.

I tried a TRV head on a valve and it would seem the mechanical versions have around 10°C between fully open and fully closed, even the electronic type have a very slow opening and closing, so all down to the lock shield valve setting, and those in this house I have tried to adjust have been wide open.

 

[MeldrewsMate]

...but many I can't reach, stuff piled in front of radiators...

Welcome to my world Eric.
Imagine how hard it was to fit those rads, with all that stuff piled in front of them.