# How do TRVs work?

## Do TRVs open and close based on the room temp or the water tem?

Based on the temperature of the room
5
100%
Based on the temperature of the radiator
0
Based on the temperature of the water flowing through the TRV
0

I'm having an argument with a friend of mine about how Thermostatic Radiator Valves work. I believe they measure the temperature of the room and open and close as the temperature changes, he believes that they measure the temperature of the radiator or of the water flowing through the valve. Can anyone give me the definitive answer please?
thanks
billandben
Rank: Apprentice
Progress to next rank:
0%
Posts: 5
Joined: Sun Jan 27, 2008 10:57 am

The temperature of the room.

If it was the temp of the rad or the water. Then 21 degree's would be met quickly and the room would still be stone cold.

The head of the TRV is what senses the tempertaure, as the temp rises the liquid will expand in turn pushing the pin down to close the valve.

htg
htg engineer
Rank: Project Manager
Posts: 3256
Joined: Tue May 22, 2007 5:22 pm

[quote="htg engineer"]The temperature of the room.

If it was the temp of the rad or the water. Then 21 degree's would be met quickly and the room would still be stone cold.

The head of the TRV is what senses the tempertaure, as the temp rises the liquid will expand in turn pushing the pin down to close the valve.

htg[/quote]

The TVR,s in my bedrooms come first thing in the morning even if they are set at the lowest setting but go off later on, is this right or should they be stone cold all the time ?
mblago
Progress to next rank:
7.7%
Posts: 26
Joined: Mon Feb 18, 2008 6:57 am

?????????? explain.

The radiator will come on, when the room reaches the temperature set on the TRV the rad valve will be closed (no flow of water, radiator will cool eventually unless the room temp drops first)

When the room temp drops the rad valve will open.

and so on..................

htg
htg engineer
Rank: Project Manager
Posts: 3256
Joined: Tue May 22, 2007 5:22 pm

Display posts from previous
Sort by
Order by

• DIY How to Project Guides
• DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!

• Related Topics