installer sitting on floor looking at a document on tablet computer


If you’ve got a query on a technical issue, we have lots of information in our technical tips and FAQs. But if you can’t find what you are looking for then send a tweet to @DraytonHeating, email, or call our technical support team on 0333 6000 622.

Homeowner FAQs

Below we have answered your most frequently asked questions about heating systems. However, if you can't find what you are looking for please do not hesitate to contact us.

Controls Basics

What controls should I have in my home?

As a minimum, you need to have both time and temperature controls which have the ability to turn off the boiler when there is no demand. It’s also recommended to fit TRVs in each room.

What is the difference between a combi-boiler and a conventional boiler?

A combi-boiler is typically found in smaller properties and provides on demand hot water compared to a conventional boiler that requires hot water to be stored in a cylinder.

Do the controls differ for a combi-boiler and conventional boiler?

Yes, for a combi boiler there’s no need to control the hot water as it’s on demand so you will typically use a single channel controller. A conventional boiler stores hot water in a cylinder, so this also needs to be controlled for time and temperature, typically using a two channel controller.

What controls do I need to comply with Boiler Plus?

All installations of gas boilers (both new and replacement) need to have a minimum ErP efficiency rating of 92% and include both time and temperature controls.

If the installation is a combi boiler (both new and replacement) ONE of these additional measures needs meeting.
Flue Gas Heat Recovery
• Weather Compensation
• Load Compensation
• Smart Controls featuring automation and optimisation functions

The Drayton product range offers a solution to meet all of these except flue gas heat recovery as this is provided by the boiler manufactures.

Thermostat FAQs

What is a room thermostat?

A room thermostat allows you to maintain a comfortable temperature within your home and turn your boiler off when the set point is achieved.  

Do I need a room thermostat?

Yes! A room thermostat is an important component in controlling your heating to optimise the efficiency of your system and comply with the requirements of Boiler Plus.

How does a room thermostat work?

A room thermostat measures air temperature and can demand heating when the ambient temperature is below the set point. They are typically used alongside time controls and have the ability to turn off the boiler when set point is achieved.

Where should the thermostat be located?

When using a single room thermostat to control the whole house, it should be located centrally in the house in a room that achieves the required temperature last. It needs to be in free space so that the air flow over it is representative of the temperature in the room, so should be kept away from heat sources and not covered by furniture or curtains.

What temperature should a room thermostat be set at?

The recommended setting for maximising comfort and energy efficiency is 18°C-21°C but it is down to personal preference. We would suggest trying different temperatures until you find the lowest comfortable temperature for your requirements.

Do I need more than one room thermostat?

A room thermostat is designed to control the heating within its zone. If you have a house under 150sq metres one heating zone (which means one thermostat is adequate). If your house is more than 150Sq metres, you need two heating zones e.g. one upstairs and one downstairs; in this case you will need two thermostats.

What does RF stand for?

RF stands for radio frequency and is a method for devices to communicate with each other without the need for wires.

Should I have a wireless room thermostat? 

In terms of functionality a wired and wireless thermostat do the same thing. However, if your property doesn’t already have a wired thermostat installed, then fitting a wireless system may be the easiest solution. Choosing a wireless device means you don’t have to channel out walls to wire it in therefore making it easier to install with minimal disruption and less mess.

What thermostat do I need to use with a Combi-boiler?

As combi boilers only require controls for central heating the easiest method is to install either a wired or wireless programmable thermostat where both time and temperature settings are handled in the same unit.

What is a cylinder thermostat and where would I use it?

A cylinder thermostat is used to measure the temperature of the hot water stored in a cylinder when using a
conventional boiler. It’s used in conjunction with a time control and whilst it cannot influence the temperature of the water entering the cylinder, once the set point for the whole cylinder is achieved it can stop the call for heat.

Time Controls FAQs

What are time controls?

Time controls are devices that allow you to set when your heating comes on and goes off. They can be programmed so that you never forget to turn your heating off (or on). Time controls work alongside your temperature controls. When your time control is on, if the room reaches the set temperature the thermostat will override the time control and turn off your heating. Timeswitches and programmers are both time control devices.

What is a timeswitch?

A timeswitch is a single channel control, typically used with a combi boiler and allows you to control the times the heating switches ON/OFF.

What is a programmer?

A programmer manages the timings for two channels and is typically used with conventional boilers, where both heating and hot water need to have time control.

Can I set different times for different days?

Drayton has a range of time controls that give you different levels of flexibility. Some allow you to set a 24 hour programme that will be repeated on a daily basis, others offer a 5 day/2 day programme which enable you to set different programmes for the week and weekend, and some allow you to set a different programme for each day.

What happens to my programmed times when the clocks go back or forward?

Most Drayton time controls will automatically adjust for summer and winter time, making bi-annual adjustments a thing of the past. Check the product pages for more information.

What happens if there is a power cut – do I have to reset the programmes?

Most Drayton digital time controls have an internal memory and a lifetime battery to maintain the clock so even after a power cut it will not need resetting.

How many timing periods can I have in a day?

This will be depending on the module. Check the product pages for more information.

What happens if I want heating on when my time control isn’t set to be on – do I need to reprogramme it every time?

No, Drayton time controls have Boost and Advance features that enables you to override your schedule.

Is the display always illuminated?

This is dependent on the module for instance, on the LP range the backlight is illuminated all the time compared to the new digistat where the backlight responds to a click of the button.

Do I need a time control if I have a programmable thermostat?

No, a programmable thermostat controls both temperature and time.

Programmable Thermostat FAQs

What is a programmable thermostat?

A programmable thermostat is a single unit that combines the functionality of a time control and a room thermostat. Instead of having ON/OFF periods, a programmable room thermostat lets you set different temperatures at different times throughout the day.

What is the difference between a RF and standard programmable thermostat?

RF, standing for radio frequency, is the wireless version. It has the same functions as a standard thermostat but because it has no wires it is easier to install.

Can I use a programmable thermostat with a combi-boiler?

Yes, in many cases this is the easiest way to control a combi boiler as it combines time and temperature into one unit. 

Are they mains or battery operated?

Versions of both are available. The battery-operated control is used for a two wiring installation and the mains version is used for a four wire installation.

Can I set different times/temperatures for different days?

The new digistat is universal so you can choose 24hr, 5 / 2 day or 7 day within the user options.

What happens to my programmed settings when the clocks go back or forward?

The Drayton programmable thermostats have an internal memory and a lifetime battery to maintain the clock so even after a power cut it will not need resetting.

How many timing periods can I have in a day?

On most Drayton programmable thermostats there is a choice of 2, 4 or 6 time/temperature periods in a day, you can simply select your preference. However, if you opt for New Digistat then you can set up to 8 time/temperature periods in a day.

Smart Controls FAQs

What is a smart control or smart thermostat?

A smart thermostat is an internet connected heating control that allows you to manage your home’s temperature and heating schedules from a remote location, using your smartphone or tablet.

What can I use a smart control for?

You can use an app on a smartphone or tablet to turn the heating on or off, and adjust the temperature without needing to be near the home – as long as you have an internet connection. For instance, if you have gone to work and left the heating on, you are able to remotely switch it off with the touch of a button, allowing for greater freedom and control over the amount of energy you are using.

Can I adjust heating schedules?

It’s really easy to adjust heating schedules on the go using a smart control, which means you can reduce energy consumption by tailoring heating periods to fit in with your lifestyle and routine.
If this routine is disrupted whilst you are away from home, you can make tweaks in order to prevent energy wastage that could occur if schedules are not adjusted, for example if your house is heated with no occupants.

What's Draytons Smart Control? 

Drayton’s smart control is the Wiser system. Upgrading from a traditional system to Wiser can be as easy as swapping out the existing timeswitch or programmer for the appropriate Wiser hub. As well as giving you smart capability, Wiser also lets you add other devices such as smart radiator thermostats to give room by room control and really drive the efficiency of your central heating system. For more information on Wiser go to

Radiator Control and TRV FAQs

What is radiator control?

The output of a radiator can be controlled by restricting the flow of hot water in or out. This can be done a number of ways with manual valves, traditional TRVs and smart radiator valves.

What is a TRV?

A TRV is a Thermostatic Radiator Valve. TRVs are fitted to radiators and used as a type of thermostat to regulate the air temperature in an individual room.

How does a TRV work?

Both traditional and smart TRVs sense the air temperature in the room and begin to close off the valve once the desired setting is reached. Traditional TRVs do this mechanically by using a sensing head that expands the temperature, so these are fit and forget products that require little to no maintenance.

What is a smart TRV?

Smart TRVs take the place of a traditional thermostatic radiator valve and close the valve using a motor that’s driven by batteries that will need to be changed periodically. These offer greater accuracy and have the ability to stop the call for heat when set point is achieved. They can also directly call for heat in individual rooms avoiding energy waste.

What is an auto-balancing TRV?

Auto-balancing TRVs permanently and easily balancing a radiator heating system, reducing home energy bills.

Why does my radiator not seem to shut down?

This may be because the radiator is undersized for the room it is fitted in. If this is the case, then the room will never reach a high enough temperature for the valve to shut down. This negates the use of a TRV and so a plumber should be called to establish if the radiator is correctly sized to the room it is in.

My radiator stays hot no matter what setting I set the TRV head to.

This may be a faulty head. Change the suspect head for one you know is working fine. If the radiator shuts off/opens up with the new head on, replace the original TRV. If the radiator still does not shut down, the problem most likely lies at the valve and it will need replacing by a plumber.

My radiator stays cold no matter what setting I set the TRV head to.

This may be a faulty head. Change the suspect head for one you know is working fine. If the radiator shuts off/opens up with the new head on, replace the original TRV. If the radiator still does not warm up, remove the head completely. This should open the valve fully and allow flow through into the radiator. If the radiator still does not warm up, bleed the radiator (in case of an air-lock). If this does not help, and the pipe leading into the valve is hot, then it may be a problem with the valve itself and so it should be replaced.

What are the temperatures in relation the numbers on the TRV4 head?

SettingTRV 4 °CRT414 °CRT212 °C
*7.1 - 9.16.3 - 8.39.7 - 11.7
111.3 - 13.19.7 - 11.713 - 15
215 - 1713 - 1516.4 - 18.4
319 - 21.0116.4 - 18.419.7 - 21.7
422.9 - 24.919.7 - 21.723 - 25
526.8 - 28.823 - 2526.4 - 28.4
MAX30.8 - 32.826.4 - 28.429.7 - 31.7

My TRVs / radiators are making a banging noise – how do I solve this?

Banging or hammering in a system is caused by excess pressure or water turbulence in a system rapidly lifting and shutting the valve seat. If this is happening it would be advisable to get a qualified heating engineer to take a look at your system.

Should TRVS be fitted to my heating system?

Yes, having multi-room control through the use of TRVs can improve the comfort and cost of heating your home and save you up to 19%.