A central heating digital programmer is a more advanced timer and thermostat that allows you to decide when to set your heating to come on and off every day and what temperature to reach. Programmers allow you to preset heating schedules around when you are usually home and keep the heating off when you are likely to not be home.
Programmers for your boiler and central heating come as a single channel and a dual channel. The single channel option is for a combi boiler, as a combi boiler has instant hot water and just requires the programmer for when to turn the heat on.
The dual channel, also known as two-channel system, is for a boiler where one set of switches control the hot water cylinder and a separate set for the heating. These can also be used to control a second heating zone.
Replacing a faulty digital programmer or upgrading an old timer to a modern programmer (e.g.; the Danfoss TPOne™) does not require too many hours of labour from the heating engineer so the simplicity in the job helps to keep the cost down. A battery powered programmer like the Danfoss TPOne™ costs about £60 and a mains powered Danfoss TPOne™ costs about £80. These will only require your heating engineer to do a couple of hours labour to get the programmer installed and ready for use.
How much labour costs to fit a programmer |
Per |
Average cost |
Replacing a faulty programmer |
Per hour |
£90 |
Upgrading an old timer with a new programmer |
Per hour |
£160 |
Upgrading to a smart programmer |
Per hour |
£160 |
A boiler will need a thermostat to instruct the boiler when to heat the house. Depending on temperature rather than a specific time during the day. If your home is left empty for days, weeks, months in winter, it is important that the home stays above 5 degrees (best to set it to not fall between 8-12 degrees celsius) to avoid any frost damage. This stops water from expanding as the water freezes, and resulting in a burst pipe or no flow of water to the boiler. Most thermostats nowadays are programmable thermostats meaning you can do timed settings through-out the day for heating to come on, making the central heating system more energy efficient.
Some combi boilers have a built in timer, with notches that you push outwards to represent times to come on and inwards to represent times switched off during the day. A boiler will operate without a programmer as long as there is a thermostat and timer built-in.
A thermostat will control the temperature of the boiler. Whatever the temperature is set to, when the thermometer / thermostat reaches temperature, it will instruct the boiler to switch off, or when the room falls below the desired temperature, a thermostat tells the boiler to turn on and start pushing hot water around the pipework to heat radiators, towel rails and underfloor heating.
A programmer does this as well as allows different time schedules to be set for temperature settings at different times during the day. E.g.; a programmer can set the heating to come on for an hour when you wake and get ready for work and then switch off as you leave for work, and have the boiler turn back just before you are due home to start heating the house for your arrival.
A timer has a limited option of allowing you to set the heating to come on at the same time throughout the week. A programmer is more advanced with better features of allowing you to set different timed options for different days of the week, e.g.; having the heating come on later or for longer over the weekend when you are having a lie-in and staying in for the day. A 7 day programmer (the most advanced) allows you to have a different schedule for the heating every day, so 7 unique days. A 5/2 programmer means that the weekend can have different settings from the weekdays. Having a Smart thermostat means the App on your smartphone acts as the programmer and you can have a different heating schedule for every day of the week.
The Smart thermostat makes the programmer redundant. You can either remove it from the wall of the house or leave it in situ, in case you move home and take your Smart controls with you but the programmer will no longer be talking to the boiler as the schedules of times and temperatures will all be controlled via the App on your smartphone.