Radiator valves in room with thermostat question

eidolon · 31 May 2017 at 22:05

Probably a stupid question but I've never dealt with central heating systems before.

I'm replacing a single radiator in my living room with a pair of radiators on opposite walls. I'm aware that you're not supposed to fit TRVs on radiators when they're in the same room as the thermostat so what do you fit instead?

Also, where's the best place to buy 10 Drayton TRVs from? Any particular site you're recommend?

Jokester · 31 May 2017 at 22:19

Just fit a valve cap on it, or if you already have a TRV on it, I just leave mine fully open all the time.

eidolon · 31 May 2017 at 22:35

The new radiators don't come with any valves apparently so do I need something to stick in the holes? Or should they come with something to do that?

Jokester · 31 May 2017 at 22:39

TRVs normally connect to the valve stem - if you don't have TRVs then you just cap off the stem, if they don't have valves in the actual pipework then you have nothing to worry about.

a1ex2001 · 1 Jun 2017 at 04:54

I'd fit trv's and leave them full open never know when you'll want to move the thermostat!

FlyingFish · 1 Jun 2017 at 07:06

Just fit trvs on both rads. If your unsure you can normally get a trv and lockshield pack from most merchants, and that will sort you out.
The idea (building reg) of not having a trv on the rad with the room stat, always seems pointless to me. You have no way of regulating the room temp by the radiator, only the room stat, which obviously turns the whole heating off!

robj20 · 1 Jun 2017 at 07:20

FlyingFish said:
Just fit trvs on both rads. If your unsure you can normally get a trv and lockshield pack from most merchants, and that will sort you out.
The idea (building reg) of not having a trv on the rad with the room stat, always seems pointless to me. You have no way of regulating the room temp by the radiator, only the room stat, which obviously turns the whole heating off!

Zero point having a TRV and thermostat in the same room, if you want the room 20c you set the thermostat to 20c job done no need for TRVs. Bad idea to have a TRV on all radiators you could damage the boiler. Best to at least remove the TRV and fit the cap instead.
Best option is to fit a lockshield valve to both sides.

FlyingFish · 1 Jun 2017 at 08:33

So once that room reaches its temp, the entire heating goes off, regardless whether other rooms are up to temp or not!

And statements about trvs being bad for boilers is rubbish. Combi's have internal bypass. Y-plan has natural bypass, S-plan should be fitted with one anyway. And most system boilers have them. The only time, a complete trv system would be an issue is if the manufacture hasn't designed an internal one (cheap poor boiler from years ago) or the plumber isn't smart enough to have done his installation correctly.

The cap you refer to for a trv, is a decorating cap to seal off the valve.

LeeUK · 1 Jun 2017 at 11:41

My controls/thermostat is freestanding and wireless meaning I can move it to anywhere in the house. Only radiator without a TRV is the one at bottom of stairs, can't turn it off either.

a1ex2001 · 1 Jun 2017 at 12:33

FlyingFish said:
So once that room reaches its temp, the entire heating goes off, regardless whether other rooms are up to temp or not!

And statements about trvs being bad for boilers is rubbish. Combi's have internal bypass. Y-plan has natural bypass, S-plan should be fitted with one anyway. And most system boilers have them. The only time, a complete trv system would be an issue is if the manufacture hasn't designed an internal one (cheap poor boiler from years ago) or the plumber isn't smart enough to have done his installation correctly.

The cap you refer to for a trv, is a decorating cap to seal off the valve.

The reason not to put a trv in the room with the thermostat is if you set it lower than the thermostat the room can never get up to temperature to turn off the system making the thermostat a pointless waste of money and wasting money as the system will never turn off!

FlyingFish · 1 Jun 2017 at 13:31

But having a thermostat on the radiator gives you the ability to at least control the heat, as opposed to the radiator always being on with the heating. No house or installation is perfect, so having the trv fitted (the valve is only £14) give you the control to 'balance' how the heating comes on and off by the thermostat.

I understand what your saying, and also what building regs are trying to accomplish. I just think for the cost it's much better to have it, than not.

Mick

Tinders · 1 Jun 2017 at 22:14

Just use a manual rad valve and cap. Ebay is a good shout for valves, recently picked up 10 peggler terrier II TRV's for £45 and the manual valves (also 10) for £25. Cheapest merchant price for the TRV was around £14 ea.

gEd · 1 Jun 2017 at 23:15

Isn't this why you are supposed to simply install the thermostat in the coldest room in the house, let this control the temp of this room )with a rad that has not TRV) and let the TRV's control the temps in the warmer rooms???

BinnsY · 2 Jun 2017 at 10:00

FlyingFish said:
So once that room reaches its temp, the entire heating goes off, regardless whether other rooms are up to temp or not!

This is why you should install the thermostat in the coldest spot in the house. You then set the temperature so that that area reaches a comfortable temperature. The idea of TRV's is that you can then make other areas of your house cooler to save money. The thermostat itself is meant to be regulating whether your house is upto temperature. All you accomplish by turning a stat down on the rad closest to the thermostat is that your stat and the trv fight each other. If your house isn't warm enough when the stat clicks of you turn it up a degree or two, then use the stats in other rooms to cool them down if they are getting too hot.