Control radiator…?

LoopyLoops

Hoping someone is able to explain, we’re a little confused. We moved into our house in April, had the boiler replaced - now a combi.  

Boxt did our boiler install, all good. Dining room is now husbands office and that radiator doesn’t have a thermostat control on it.  When he asked Boxt, they said it’s the control radiator and we have to have one (that’s fine).  But he’s concerned he’s going to have to have it on full and be very hot if his radiator is on full all winter.  Do we need to pay to have another radiator changed to the control? We have a WiFi thermostat we can put anywhere. 

I really don’t get central heating as I haven’t really had to.  We have rented for quite a while, so had no say and before that we had warm air heating, so totally different. The last time we owned a place with central heating they didn’t have these TRV’s on them. Thanks in advance for any helpful guidance! Apologies if this is a daft question… Thanks! 

Albermarle

AIUI, you need one radiator that does not have a TRV on it and is on all the time the heating is on.
If not it is possible all TRVs could turn off with the boiler still running, which is apparently not good for the system.
Also the room with the thermostat should not have a radiator that can turn itself off with a TRV.
A plumber could easily enough put a TRV on the dining room radiator and take it off another one, and you could put the thermostat in that room. The hallway is a common place.

MyRealNameToo

LoopyLoops said:

Boxt did our boiler install, all good. Dining room is now husbands office and that radiator doesn’t have a thermostat control on it.  When he asked Boxt, they said it’s the control radiator and we have to have one (that’s fine).  But he’s concerned he’s going to have to have it on full and be very hot if his radiator is on full all winter.  Do we need to pay to have another radiator changed to the control? We have a WiFi thermostat we can put anywhere. 

I really don’t get central heating as I haven’t really had to.  We have rented for quite a while, so had no say and before that we had warm air heating, so totally different. The last time we owned a place with central heating they didn’t have these TRV’s on them. Thanks in advance for any helpful guidance! Apologies if this is a daft question… Thanks! 

The thermostat tells the boiler when the home has hit the desired temperature as such it should be in a room heated by a radiator without a TRV. 

A TRV sets the individual radiator on/off based on the temperature in the room. 

The issue you have is if you set the TRV in the room to 18C but the thermostat to 20C the boiler would be on constantly because the radiator in the room has cut out before its hit what the boiler is trying to achieve. 

As such it should be in a room with a radiator without a TRV so the boiler knows what temperature it's gotten the home to. The TRVs in other rooms can then be used to lower the temperature below that of the thermostat if required. 

Thats the theory, it doesnt quiet account for the uneven heating of different rooms though so just because the dining room in your case has no TRV and has the thermostat at 20C doesnt guarantee all rooms manage to hit 20C. My thinking has always been that the thermostat should be in the room you want the warmest, probably the lounge in most cases, and then the rest of the house with TRVs to reduce their temps or deal with matters if they have better insulation etc. Probably some consideration has to be given if you have an openplan kitchen meaning the room heats up from non-radiator based sources 

Vitor

As a general design rule, the room where the the boiler thermostat is located should not have TRV on the rads (or they are fully open) so that the valves don't 'compete' with the room thermostat. Another rad, typically in the bathroom, has two lockshield valves that are always slightly open so that water can pass through and the combi's pump isn't pushing against a closed circuit. 

Boohoo

A photo of the rad valve's may give a better idea.

Have you actually tried the heating on in the home in the past week to see how hot the room gets?

You could just turn that rad off when it gets hot for your partner. Only do that if there is another non trv rad on the system though.

Another thought is have the rads been balanced since the new boiler was installed and was the boiler in the same place?

WIAWSNB

Although it's without a TRV, it doesn't mean the rad has to be running on full - you can tweak that rad's control valve down until it provides just what the room needs, tho' if it is acting as the 'by-pass' rad, it shouldn't be turned fully off.

Since you have a WiFi thermostat, what's been said above makes sense - make that office the 'controlling' room for the house's CH (it would usually - ideally - be the sitting room).

So, sit the thermostat in there, and set it at the temp required in that room, say 19oC. Set all the other rads in the house to the TRV number which corresponds with their individual needs - sitting room 3+ (~20/21oC), bedrooms, below 3 (~18oC), hallway 2+ (~16oC) etc. Then wait until it's chilly and the CH is required - turn on the CH. 

What you want to achieve is for every room to heat up to their individual set temps (TRVs), including the office, at roughly the same time. 

If the office gets to the thermostat-set temp - say 19oC - before the rest of the house reaches their desired temps, then tweak the control valve on the office rad shut a wee bit to make that rad less powerful. And so on...