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Quick wins for reducing your heating bill


Jo Alsop

Heating Hero

The Heating Hub

Jo explains the basics of your heating system and how to make small adjustments that will reduce your gas bill and improve efficiency


We need quick wins for reducing our heating bills this winter, but we need to know how to make those changes to our heating system. In this blog we provide a breakdown of your heating system components and guidance on how they should be set up to minimise energy use.

Heating system basics

Boiler types: You will either a boiler that works with a hot water cylinder or a combi boiler (aka combination boiler) that produces heating and hot water from a single unit. (You will not have a combi boiler that works with a hot water cylinder).

Hot water cylinder: copper or steel cylindrical tank often in the cupboard on the landing. Copper cylinders can can a foam insulation cover (can be blue, green or yellow). Older copper cylinders have a red insulation jacket. Unvented cylinders are steel, often white and with a red expansion vessel nearby.

Room Thermostat: You will usually have some form of room thermostat on a wall somewhere either as a dial or a digital display. This sets your room temperature.

Programmer: You may have a separate programmer or a combined programmable room thermostat. You use this to set the times the boiler is on, for example 6am-8am and 5pm-10pm.

Radiator valves: Many homes have thermostatic radiator valves (TRVS). These are on the radiator with a dial that shows numbers of 1-6. The numbers represent room temperatures. No. 2 is around 15degC and No. 3 is 20degC.

Adjusting your heating system to use less energy

Timing the boiler v keeping the boiler on low

There is always some debate around just having the heating on when you need it and keeping it on low and not letting the boiler turn off. For most households, you should only have the heating on when you need it. Nesta's Salford Energy House tests found that heating your home for short periods uses 14% less gas, saving around £130 per year, than leaving the heating on at a low level all the time, including when you are out at work and in bed. 

You can do this by setting the times on a programmer. If you don’t have a programmer, you can turn the thermostat down really low to turn the boiler off and turn it back up again when you’re home.

The exception to this is a perfectly optimised boiler running at a low temperature for someone working from home. Very few of us have perfectly optimised boilers however, which require an advanced heating control and a boiler adjusted to the needs of the home, because 99% of installers have not be trained to specify or set up condensing boilers correctly. 

Using your thermostatic radiator valves (TRVs)

You should target the temperature set on your room thermostat and slightly lower upstairs. No. 2 or II on your TRV dial will be around 15degC and No. 3 or III will be around 20degC. If you set some rooms at a lower temperature or turn the TRVs off you must remember to shut the door on those rooms. Warm air will move to cold spaces and you will heat that space indirectly if you leave the door open. A Dept. of Energy & Climate Change report in 2012 found this saved around 4%.

Timing your hot water cylinder for once a day

You should set your timer for hot water if you have a cylinder. If you shower in the mornings, set the cylinder to come on before you need it and leave for 24 hours if possible. The key is to not use to much of the water you have heated, so short showers. The cylinder will lose around 5-7 degC over a 12-hour period, so you should still have sufficient hot water for the day and evening. It is important that the cylinder is well insulated and you can add insulation to uninsulated cylinders and it costs about £15. NB The HSE state that cylinders should be heated to 60degC to kill of legionella bacteria quickly. 

If you always seems to have a lot of hot water it maybe that your boiler is always heating your cylinder. This will cost you more money and you need to time it or manually switch it on for the period before you need it and then switch it off. You should also check that your immersion is not switched on permanently. This is the electric back up heater for your hot water cylinder, or can the be main source of hot water for households off the gas grid.

Turning down the flow temperature on a combi

If you have a combi boiler, which a boiler without a hot water cylinder, you can reduce the flow temperature for heating yourself and this will help the boiler run much more efficiently, saving around 9% on your total gas bill. Most UK households are well insulated enough to drop the flow temperature from 80-60degC without a reduction in comfort. Go to our Mission page for lots of help and examples of how to do this. NB if you have a boiler that works with a hot water cylinder we do not recommend this as a DIY change.

Turn off the pre-heat

Again on combi boilers, many have a pre-heat function which keeps a little bit of water in the boiler hot. This is designed to reduce the amount of time it takes to get hot water from your boiler to the taps. For most homes this will not be necessary and the boiler is firing all day and all night using gas for no reason. Go to our Mission page for instructions on how to turn this off on Worcester, ideal and Vaillant boilers.

Bleeding radiators

Air in your radiators makes it hard for them transfer their heat and warm you room. If they are working harder then your boiler is also working harder and using more fuel. Bleeding the radiators has a big impact on boiler efficiency. Air in your radiators also reacts with the water in the system and causes corrosion, another source of inefficiency.

Turning down the thermostat

We’ve all heard about this one. Just note that many thermostats are not very accurate, so whilst you may think it is set to 18degC, it’s actually 20degC. You will need to set it to what feels comfortable or what you can tolerate.

Heating the body

Not technically a heating matter, but certainly one that helps us live with a lower room temperature. The benefits of thermal underwear, thick socks, fur boots, layers and a scarf cannot be underestimated. No one wants to dress like they’re ready for blizzard weather whilst in the home, but many households are facing a tough winter and dressing warmly really does help.


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