Asked by: Qiumei Knippschield
home and garden indoor environmental quality

What do thermostats on radiators do?

Last Updated: 5th January, 2020

Thermostatic radiator valves do not control the boiler; they reduce the flow of water through the radiator which they are fitted to when the temperature goes above a certain setting. Set them to the level you want for the room; a lower setting uses less energy and so will save you money.

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Similarly, it is asked, how do thermostats work on radiators?

The TRV is a valve that self-regulates, meaning it adjusts the flow of water into your radiator depending on the setting. And as the room temperature changes, the valve head expands, adjusting a pin in the valve body so that it opens or closes.

Beside above, which side of a radiator does the thermostat go? Many modern homes will have TRVs – Thermostatic Radiator Valves – attached to most of the radiators on the opposite side from the lockshield valves. A TRV should always be fitted to the inlet on the radiator and the LSV to the outlet.

Moreover, what do the valves on a radiator do?

Each radiator in your home needs a pair of radiator valves which act like taps, enabling you to control how much heat they give out. One of the valves controls the amount of hot water entering the radiator and the other (known as the lockshield valve) balances the system by controlling how much heat the radiator emits.

Is it cheaper to leave the heating on all day?

According to experts at the Energy Saving Trust, as well as British Gas, the idea that it's cheaper to leave the heating on low all day is a myth. They're clear that having the heating on only when you need it is, in the long run, the best way to save energy, and therefore money.

Related Question Answers

Hmidou Nathanson


What temperature should central heating thermostat be set at?

Your room thermostat should be set to the lowest comfortable temperature, typically between 18 and 21 degrees. You don't need to turn your thermostat up when it is colder outside; the house will heat up to the set temperature regardless.

Paciana Ubide


What do the numbers mean on a radiator thermostat?

The numbers on a thermostatic radiator valve refer to the temperature in the room, not the radiator. This is a common misconception, so don't worry if you weren't aware of this before. If the room is cold, the the TRV will allow more hot water into the room to heat it up.

Haytham Elayavalli


Do you need TRV on all radiators?

You should have thermostatic radiator valves (TRVs) on all radiators but not in the same area as a wall thermostat, it is possible that this room may never get warm enough to turn the boiler off via the wall thermostat if the temperature in this area is being controlled independently by a TRV.

Doriana Dewert


Should radiator valves be fully open?

As you progress further away from the boiler, the Lockshield valve will need to open slightly more. It's not uncommon for the Lockshield Valve in the first radiator to be open around one-quarter of a turn, while on the last radiator, it may need to be fully open.

Marjolein Cavem


How do you turn off a radiator with a thermostatic valve?

To remove a radiator:
  1. Turn the radiator valves off.
  2. Disconnect the radiator at the Thermostatic Radiator Valve (TRV).
  3. Disconnect the radiator at the lockshield valve.
  4. Empty the water from the radiator – you may need to open the radiator bleed valve.
  5. 'Cap off' the TRV and lockshield valve.

Alexis Cadima


How do thermostats work?

At its core, a thermostat is simply the controls used to regulate temperature in a heating system. You can set a preferred temperature, and the thermostat works to keep your room or boiler at this desired level. If the home starts to drop in temperature, a thermostat switches the heating on to warm it up.

Jiri Foos


Can I turn off radiators in unused rooms?

As long as you close the doors so the cold air doesn't seep into the rest of the house, you will save money by turning off the radiators in unused rooms. By doing so, you'll prevent the water in the system running through that particular radiator.

Valdemir Rottmuller


Do you open both valves on a radiator?

Best said: I would say very generally speaking that the first radiator or two on a circuit need their lockshield valves just slightly open, but each rad beyond that should have lockshields increasingly more open until last radiator is full open.

Sanja Vior


Why are my radiators cold at the bottom?

A radiator that is cold at the bottom is usually caused by a build up of sludge in the system. As the sludge is heavier than water, it settles at the bottom which prevents water and heat flow to the bottom of the radiator.

Judas Romans


Which side of a radiator is the flow?

Normally (but not necessarily!) the flow is on the left as you look at the rad.

Calin Lefarth


Which way does water flow through a radiator?

The water, which leaves the radiator, flows into a return pipe, which goes back to the boiler. The same process occurs in all the other radiators. Therefore, all of the radiators receive water at more or less the same temperature. Chrome inlet and outlet (lockshield) valves.

Letha Boulet


Are smart radiator valves worth it?

How much do thermostatic radiator valves cost? Electronic/smart TRVs are also worth considering, as part of a smart heating system. This way, you can control each separate radiator from an app on your phone, even if you're away from home. This is the best way to control heating and track energy usage.

Dahane Toulouse


Does it matter which side of radiator flow and return?

Should TRV's go on the flow or return pipe when fitting to radiators? Answer from Steve Harris, technical services engineer at Wavin: The vast majority of new TRV's are bidirectional and can be fitted to either the flow or return, but it is always good practice to fit them to the flow side.

Habiba Klemper


How do you fit a thermostat to a radiator?

How To Fit Thermostatic Valves To Your Radiator
  1. Isolate the radiator. Isolate the valves on either side of the radiator.
  2. Isolate water supply to primary system. Isolate the water at the primary system and turn it off at the electricity supply.
  3. Remove radiator from wall.
  4. Remove valve.
  5. Fit new valve.
  6. Re-fit the radiator.
  7. Fit adaptor.
  8. Fit the head.

Maris Azam


Do you have to drain the system to change a radiator valve?

Locate the drain off
You'll need a hose at this point which will connect to the drain off and then you'll want the other end of the hose to be outside, ideally where the water can run off into either soil or an outside drain. Open the drain cock and when it's empty you're ready to change the radiator valve.

Noble Lodewick


How do I balance my heating system?

To balance your central heating system, turn off your heating system and allow all radiators to cool down. Open both of the valves for all of the radiators and turn on the heating. You may need some help but you now need to go to each radiator and work out when they heat up and what order they heat up in.

Sergiy Niell


Why are my radiators not heating up?

2. Check for Trapped Air and Bleed Your Radiators. If just one (or a few) of your radiators aren't heating up, the most common reason for this is trapped air. If you've just turned the heating back on after the summer, air can become trapped in your radiators, causing them to be warm at the bottom but cold at the top.

Bojan Brian


How does water flow through a central heating radiator?

An electric pump pushes the heated water through the system. The water flows around a closed loop inside each radiator, entering at one side and leaving at the other. Because each radiator is giving off heat, the water is cooler when it leaves a radiator than it is when it enters.