Troubleshooting a problem in the kitchen

Troubleshooting & Resources

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.

Technical Tips

Take a look at our technical tips for advice on heating control installation and maintenance.

System balancing by TRV

If you’ve installed Drayton TRVs to a heating system, the balancing process will need to take place. Traditionally this would be done by using the lockshield to control flow through the radiator. By using the TRV body to regulate flow, you avoid unnecessarily re-balancing the system when a radiator has been removed during decoration.

A decorator is likely to remove a radiator by fully closing the valves at both ends to isolate it, without noting how far open the lockshield is. This means that when the radiator is re-fitted, the system is unbalanced.

You can avoid this by regulating flow using the interior of any Drayton TRV body and simply leaving the lockshield valve fully open.

Using ‘Boost’

A a 'boost' function allows users to temporarily run their heating or hot water programmes for one, two or three hours. This feature is particularly useful in period of extremely cold weather when central heating and hot water are required quickly or unexpectedly.

Volt-free controls

The controls themselves do not provide any voltage to the switching contacts – they are ‘volt free’. This allows the product being controlled to use its own switching voltage, making it suitable for low voltage applications.

Acclimatising a thermostat

When taking a digital thermostat from a cold van and installing it in a warm home, you should be aware that it won’t respond instantaneously.

The acclimatisation time for one of these units is approximately 4 degrees an hour or 1 degree every 15 minutes, meaning it could take several hours to reach the required temperature for the first time.

Finding a compatible replacement programmer

Our compatibility guide will quickly help you to compare, upgrade and replace existing programmers. Identify the existing model, select a suitable replacement and then wire accordingly.

Before removing a programmer, it’s essential to note wire colours and terminal positions, and to ensure the new backplate is wired in accordance with conversion charts.

It’s also important to check that a 3-amp fuse is fitted before mains power is restored to the system to avoid costly damage to electronic components, should a system fault occur.

Hold the transmitter unit 2 metres away from the SCR unit and then replace the batteries in the transmitter.

Replacing a TRV head but not the valve

It can sometimes be necessary to replace the TRV head to provide improved control or to simply enhance the radiator appearance and this can be done without changing the entire valve body.

TRV heads can be purchased separately and the thread connections on Drayton TRVs allow for the interchanging of heads. It’s a simple upgrade that’s quick to carry out, but remember, not all heads are compatible with all TRVs, so make sure you check first.

Commissioning a wireless room thermostat

Wireless programmable room thermostats are easy to install, and most installers only need help with commissioning the system. First, remove the batteries from the transmitter unit and allow the screen to go blank.

Then turn off the power supply to the SCR receiver unit and leave for 5 seconds. Turn the power back on and check the red light is on.

To check the SCR unit is wired correctly, press the number 2 override button once and check the green light comes on and the boiler fires.

Put the SCR unit into its learn mode. Press and hold button number 1 and then do the same to button number 2. The red light will flash a couple of times before going out. Then release both buttons – the two LED lights should be on.

Hold the transmitter unit 2 metres away from the SCR unit and then replace the batteries in the transmitter.

The red LED light will flash for approximately 7 seconds to tell you that the two units are initialising. This confirms that the radio signal is being sent and received.

The transmitter unit can then be fixed to the wall.

The receiver unit should be positioned 300mm away from any metal objects such as the boiler or a microwave or any large obstructions like solid walls that will affect the signal being sent from the transmitter to the receiver.

Replacing a timeswitch with a wireless programmable thermostat

Drayton timeswitches fitted to control heating circuits on combination boilers can be replaced with programmable wireless thermostats using the same backplates. If an existing thermostat was fitted, this would need to be bypassed.

Positioning TRVs

It is important to remember how TRVs work. Rather than sensing the temperature of the radiator, a TRV works by sensing the temperature of air around it and calling for heat where necessary.

Advise householders that concealing a TRV with furniture or behind a curtain will affect the performance of their system, making it less reliable as the TRV cannot accurately sense the temperature of the room.

Advising customers on room thermostat settings

The industry recommendation for a room thermostat is 21˚C, but this may need to be adjusted if there are health considerations or elderly occupants that require a warmer environment.

A home’s general temperature can be set to 21˚C, but installers can use TRVs to control the temperature in certain rooms, for example where part of a home has been developed to incorporate a ‘granny flat.’

Step by Step - Installing miGenie

Drayton has streamlined the process of installing smart heating controls, meaning that heating and hot water control is now as simple as it could ever be. This easy step-by-step guide outlines just how easy it is to install miGenie with the thermostat, controller and internet gateway.

Step 1: Installing the miGenie controller

If you’re using an existing industry standard wall-plate, turn power off then loosen the securing screws on the old programmer. Check that there is 70mm clearance to the right of the wall-plate and 25mm above it. Check the wiring diagram for your product model to compare terminals and, if necessary, change the wiring of the wall-plate to suit. If you have an existing wired thermostat, ensure this is disconnected and removed. Now fit the miGenie controller onto the wall-plate, tighten the securing screws and turn the power back on.

Step 2: Installing the miGenie thermostat batteries

miGenie requires two AA batteries to run, and these can be easily inserted and replaced by removing the battery covers at the back of the thermostat, and using the symbols on the connections for direction.

When batteries are running low, a low battery icon will flash in the display. During this time, miGenie will function normally.

Step 3: Checking the signal strength

The miGenie thermostat and miGenie gateway are pre-bound to the miGenie controller so they just need to be positioned in the best place for wireless communication. To help with this, there is a built-in signal strength indicator.

On the controller, navigate to ‘signal strength’ through the settings on the screen. On the thermostat, press and hold the + and – buttons for five seconds, then navigate to signal strength

Step 4: Mounting the miGenie thermostat

The thermostat can be mounted to the stand or to the wall clip in a location where it will be able to control the room temperature.  When wall mounting, the thermostat should be placed around 1.2m (4ft) off the ground and away from windows and radiators.

Step 5: Installing the miGenie gateway

The miGenie gateway is designed to be placed on a flat surface and should be located next to the customer’s internet router.

Plug the mains power cable into the gateway then connect the network cable from the gateway to the router.

Step 6: Setting up the miGenie app

To get started with remotely operating miGenie, you’ll need to download the app from the app store or Google play. Simply follow the on-screen instructions to register the device and connect the in-home equipment to the internet.

The app will allow complete control over time and temperature in individual rooms around the home, wherever and whenever you wish.

To view the 'How to install miGenie' video, click here.

For full instructions and advanced settings, please refer to the installation instructions included in the miGenie box and the full user guide available on the miGenie website.

Step by Step - Installing TRV4s

Thermostatic radiator valves (TRVs) are an important part of the central heating system, as they allow householders to control the temperature of each individual room through the radiator.

In addition, research commissioned by controls association BEAMA found that adding TRVs to a heating system can save £287 per year on household bills, so there is the potential for homeowners to make significant savings.

In this step-by-step, we will show you how to install a Drayton TRV4 - which is A-rated for energy efficiency - together with some tricks of the trade that make it easier to balance the system and service the valve.

1) Once you have drained down the system, you can start the installation. Remove the existing TRV by unscrewing the nuts on the 15mm copper pipe and the radiator tail piece.

2) Seal the new valve tail piece with 4-6 layers of PTFE tape to prevent leakage. Screw the new valve onto the tail piece on the radiator and the copper pipe.

3) Attach the TRV head, making sure that the indicator is facing forwards.  This is easiest to do if you screw the valve on when it is set to maximum, before reducing the setting to 3 once installed.

4) Now that the TRVs have been installed, the next step is to balance the system using the TRV. Balancing is important, as it means that all rooms heat up evenly at the same time. Balancing this way using the TRVs prevents the need for re-balancing the system if a radiator is removed.

5) Before balancing the system you need to turn on both the boiler and pump. Making sure that all the lockshields are fully open, start at the radiator closest to pump, checking the temperature of the flow and return pipes using clip on thermostats.

6) The target drop in temperature from the flow to the return pipe is 11˚C. If the temperature is different you need to adjust the flow rate, dropping it to increase the temperature drop and vice versa.

7) To start balancing, unscrew the valve head to expose the internal unit. Use the adjusting key to loosen the lock ring, but be careful not to loosen more than a quarter turn. The valve insert can now be rotated using the other end of the adjusting key.  It is important that you only adjust in a clockwise direction. The numbers on the adjusting key correspond with the numbers on the valve rim. Line up the number setting required to see an 11˚C drop in temperature, with the notch on the valve rim and re-tighten the locking ring.

8) It is important to note that you don’t over tighten the locking ring, and remember that you can’t set in-between numbers. The plastic internal parts mean that the ‘pin’ inside the TRV is guaranteed not to stick, which can be a problem in hard water areas and when the valve is turned on for the first winter usage.

9) Repeat this process on every radiator, working away from the pump, until all radiators have the required 11˚C drop between flow and return.  Adjusting the flow rate this way removes associated system noise. Balancing this way means the system does not need to be re-balanced if a radiator is removed, all the householder has to do is fully open the lockshield.

10) You can also replace a gland seal while the system is live.  This is the part of the TRV that is most susceptible to wear. Because the system is live there can be some seepage, so it’s best to put a towel down before starting.

11) First, remove the valve head, then, use the presetting tool to unscrew the gland seal. Finally, screw in the new gland seal remembering not to over tighten. Now you’re done you can re-attach the valve head.

12) Typically the TRV should be set to either 3 or 4 depending on the output of the boiler. Position 3 equates to a room temperature of about 20˚C, suitable for a lounge for example. Position 4 equates to a room temperature of about 23˚C, suitable for a bathroom. There are audible click stop positions on the TRV4 between each setting to facilitate the selection of positions between numbers.


To learn more about TRVs, complete our e-learning module here

Help customers to programme their system

If you are installing a programmer or programmable room thermostat, it is a good idea to help the householder set their time controls. This not only helps them save the maximum amount of energy, but also gives them a better understanding of how the heating system works, which should help to minimise callbacks.

For example, if a householder understands when their heating is due to come on and when it is scheduled to be off, as well as how to alter the time settings, then they should be able to manage their system timings without your assistance.

It’s also worth making sure that the householder understands that altering the temperature on a room thermostat will only be effective if a programmer has set the heating to be on. If the homeowner wants the heating on when the programmer has it set to be off, they need to understand they have three options:

If their programmer has a boost function they can use this to override the programmer and get a ‘boost’ of heat for one, two or three hours. After the chosen boost period it will revert back to the programmed schedule.
They can ‘advance’ the heating, which means the programmer will skip to the next ‘on schedule’ and the heating will remain on until that programme is due to end.
Finally, if the additional requirement for heat is likely to be regular, they can re-programme their control to include a new time period.
Another common time control callback occurs when the clocks change for British summer or wintertime.  This can be avoided by installing programmers or programmable room thermostats with ‘real time clocks’ that change automatically, and therefore avoid those annoying calls complaining that the heating isn’t working.

Protect against frozen pipes

If you find yourself working on a heating system that is exposed to the elements and is therefore likely to feel the full force of any cold weather, protecting the pipes against freezing can stop a system breakdown.

You can provide two-stage protection by installing a frost thermostat and a pipe thermostat to vulnerable pipework in garages or conservatories.

A frost protection thermostat is fitted in the same space as the boiler or most at risk part of the system, and works alongside the pipe thermostat, totally independently from all other timers and thermostats.

When used together, the frost and pipe thermostats ensure that the boiler is automatically switched on when the temperature drops to a dangerous level and runs until the system water temperature has been sufficiently raised.

With freezing temperatures now seemingly the norm for British winters, it’s a good idea to provide pipe protection.