What Do the Numbers on a Radiator Valve Mean?

This is a very frequently asked question, so do not worry — you're not on your own here. When it comes to standard thermostatic radiator valves (TRVs), you may be unsure as to what those little numbers mean, and which number best suits each room in your house.

This article explains everything you need to know about using your TRV as well as the cheap and easy alternative that does it all for you. First, we need to understand the reason why those numbers on your radiator valve are there…

What do the numbers on the radiator dial mean?

A common misunderstanding that people have when using thermostatic radiator valves is turning them up to a higher number when the room feels cold — assuming this will increase the temperature. In actual fact, controlling the temperature of the room is the job of your thermostat, not your TRV.

The role of trvs is to be reactive to the temperature of the room, opening up the values inside of it, based on the temperature detected. The TRV self-regulates — meaning it adjusts the flow of water into your radiator depending on the number it is set at. As the room temperature changes, the valve head expands, adjusting a pin in the valve body so that it opens or closes. Ultimately, the lower the number your thermostatic radiator valve is set at, then less water flows around the radiator and the less heat it gives out.

Setting your radiator value to max (usually 5), means you're requesting more water flow than the other settings.

How the numbers on a radiator valve work

It is not possible to precisely convert the scales of your thermostatic radiator valve to degrees celsius. This depends almost entirely on the layout of your room.

However, an approximate conversion can be made. For example, if your thermostatic valve is set to number 3, it usually means that the temperature is between 19-to-20 degree celsius which is the recommended setting for the kitchen and dining areas of your home. The suggested setting for lounge areas and bedrooms is between 3 and 4 (20-to-21 degrees celsius), while bathrooms are required to be slightly warmer on number 4. If you still require more heat, then number 5 on your thermostatic radiator valve completely opens up the valve, allowing more water to flow around your radiator — giving more heat.

Most trvs, when purchased, come with a little booklet that breaks down the conversation from number to degree. However, as a rule of thumb, we recommend setting your values at 3.

HeatingSave's thermostatic radiator valve

All of the above requires you to be reactive to the weather and to each room's temperature on a regular basis which can become a pain, while simultaneously leading to constant guesswork and more expensive heating bills. Thankfully, HeatingSave has the perfect solution to help combat this issue. Our smart trvs are the best thermostatic valves there is.

HeatingSave's thermostatic radiator valve has built-in memory to match your lifestyle and needs; automatically altering your TRVs settings to optimise comfort levels in each area of your house, building or business. Teamed up with our energy management system, it comes with dual sensor technology that ensures the most accurate temperature control.

Including its vast range of unique features (which are explained below), HeatingSave's radiator valves have the ability to save you 20-30%+ on your heating bill. This is especially the case for buildings that have infrequently used rooms or areas. HeatingSave's thermostatic radiator valve allows you to control individual radiators, giving you the ability to 'zone heat'. 

Our one-of-a-kind thermostatic radiator valves can be set up wirelessly from your laptop (smart trv), desktop PC or mobile device — giving you a complete heating diary with our easy to use web-based software.

HeatingSave's heating control software uses its built-in memory to remember heating patterns that match your day-to-day life. Additionally, these TRVs work with the building energy management system in order to give you complete control over when your heating comes on and goes off at different points throughout the day.

Our occupancy sensors are also able to optimise your heating by lowering the heating to a background temperature when there is nobody using the room. Alternatively, the occupancy sensors have the ability to detect when a room or area is being used. This means the temperature can then automatically be raised, maximising comfort levels for the occupier.

If you are looking to optimise your heating while drastically reducing your heating bills with the use of our unique thermostatic radiator valves, or for an all-encompassing BMS system, then please do not hesitate to get in touch with a member of our sales team who will be happy to help or tell you more.