Usually a boiler or heating system is not something that is on the top of people’s minds … except when your heaters have decided not to turn on and it feels like -100°c, or when you end up having cold shower’s. The other time is usually when bills are starting to sky rocket, even then people tend to prioritise on lightbulbs, appliances etc. and not pay enough attention to their heating and hot water systems
Heating and hot water account for up to an astonishing 80 percent [1] of your energy bill. Approx 60 percent is for heating and approx 20 percent for hot water with the rest accounted for by lighting, cooking, electronics, appliances etc.

Percentage of total energy bill
- Space Heating- 62%
- Water Heating – 18%
- Appliances 14%
- Lighting – 3%
- Cooking – 3%
1. Reducing draughts and heatloss
Sealing air gaps or holes where cold draughts are coming in will lead to energy savings as you are stopping heat from escaping and being wasted. Locating and sealing draughts will improve heat being retained in the home and as a result will reduce your heating bills.
There are a few techniques that can be used, thermal imaging, smoke testing and countless other methods. Mostly visual indicators will help locate these leaks as they tend to occur on or near windows and doors, storage cupboards and more. Following are the techniques used to identify draughts.
- The face and cheeks are very sensitive to temperature change. Near windows or where you see gaps and can get your face close enough, you will be able to feel the draught coming in. The stream of cooler air will be felt on your face or cheeks.
- Use a very light tissue, put it on the end of a stick or hold between two fingers, where you run it accross a draught, part of the tissue may start to move away from the rest of the tissue.
- If you have a device that produces smoke safely, you can also run this around places to see if there is a draught.
- Thermal imaging can be used to identify cold spots. For this you may need to warm the home up first and then after a short while the blue spots show colder areas where it is being cooled down rapidly, usually indicating poor insulation or a draught.
2. Adjust your boiler settings
Adjusting your flow temperature for a condensing boiler, to make sure the return temperature stays below 54 degrees (due point) can lead to increased condensing which releases additional latent heat, allowing for more stable room temperatures and energy savings. Setting the flow temparature to 55 degrees almost guarantees condensing efficiency. Only systems where the radiators are oversized or the home is well insulated will allow this. The key is getting as low as possible will increase the goal towards full condensing efficiency, ie the lower the flow temp, the higher the efficiency obtained.
The difference a condensing boiler can make is an increase in efficiency of upto 10%-12% , this translates to an 11%-13% energy usage reduction or savings of your heating bills. This is based on a non-condensing boiler being at 80% efficiency and a condensing boiler being at 90%-92% efficiency. see following wiki article for more info on condensing boilers : Condensing Boiler You can use the condensing savings calculator to work out approx savings. You can then proceed to reducing your boiler flow temperature selecting the type of boiler you have ie combi boiler flow temp or system / regular boiler flow temp.
It is much easier to adjust flow the temperature for a combi boiler than it is for a system/ regular boiler that contains a hot water cylinder. This is due to the cylinder requiring a minumum of approx 65 degrees flow temperature. Click the button below for your boiler type to show you how to adjust the flow temperature and a little bit more info on advanced savings using advanced controls.
Reduce the Flow Temp for upto 8 percent savings.
Reduce your System/ Regular boiler flow temp
Combi Boiler Condensing savings calculator
3. Correct setting of heating controls
Setting your programmers, thermostats, TRVs and controls in general in an efficient manner will lead to a better performing system and direct and indirect savings of both energy and maintenance costs. Setting the flow temperature in the previous section will help fine tune the schedule and settings for the controls. Sometimes this both goes hand in hand to produce the best outcome.
The trick with settings up controls is to start by switching things on continuously and adjusting the room thermostat temperatures until you reach a state of balance where the home maintains it’s comfort. Once you have done this, you can then proceed to setting schedules to save energy for the times your not at home.
There are more things that can be done, such as advanced modulating controls however these things tend to require much more steps and also additional higher cost purchases to achieve these further savings. Also have a look at out page on OpenTherm controls.
4. Be on the best tariff possible
Finally the most important thing to do is to be on the best tariff available depending on your situation ie meter type smart / non-smart, annual usage etc. Â Use multiple comparison sites as necessary. The tariff decides what you will end up paying at any given time.
*UPDATE 24/09/21 As of the current energy crisis, many comparison providers have pulled their fixed term deals. You should still look around to find the best possible rates. As the rates are much higher, the previous sections become much more important to work with. Only variable rate tariffs have the best unit and standing rates at this moment moment in time. If you have an electric smart meter there are special tariffs that will bring the unit rates down lower, contact us for more info.
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Conclusion
There may be several ways to save money on your energy bills. Some are possible without needing a professional to come over ie boiler settings can be done by the home occupier using the guides above with videos. Other measures will require an installer to come and install energy saving controls. There are also some indirect benefits of some of these measures that will prevent premature boiler breakdown, and in these cases it is not possible to determine the amount of savings that are possible due to this measures as they are future savings. Following is a table showing some of the measures with their savings and benefits.
Link | Item / Measure | Percentage Savings / Cost Savings | Time Required | Costs | Other Benefits |
---|---|---|---|---|---|
Flow Temperature Adjustments | Upto 10% of Heating Costs | 1 hour | - | Increased Reliability | |
Power Level Adjustments | 1 hour | - | Increased Reliability | ||
Link | Modulating Control or Weather Compensation | upto 20% | 2 hours | Upto £400 | Lower running costs and Increased Reliability |
Smart TRVs | Approx £60 per radiator | Increased comfort levels, slight reduction in energy usage. |