Mark Wilkins on emissions from domestic boilers during lockdown

It’s the time of the year when we turn on the heating, and this year there are more reasons than usual to consider how we heat our homes. The pandemic has made many of us consider what is most important to us, and what we can do to help others, and our future. Lockdown has also made us realise how much more energy we use when spending more time in the home, both working and relaxing. As we face more lockdowns in the months to come, we’ll see a clear impact on our domestic energy use as our heating bills will inevitably rise as the cold weather starts to bite.

There’s no getting away from the fact that our energy bills will rise, and so will our emissions. According to the Energy Saving Trust, on average, heating and hot water accounts for 62% of a household’s energy bill[₁]. There are many measures we can take to reduce this, and they range from small adjustments to the heating programmes we create to a complete overhaul of the entire system.

Let’s look at the bigger picture first. Since the mid-2000s, it has been a legal requirement to fit high efficiency gas condensing boilers in the UK. However, there are still an estimated 4,000,000 non-condensing inefficient boilers that are SEDBUK band G-rated in our homes. Households that can replace these boilers with highly efficient condensing boilers will see a definite reduction in their energy bills and carbon emissions that could be around 35%.

It’s not just about the boilers we install, though. We can make significant reductions to our energy use by making changes to heating systems. If your system water is clean and free of sludge, your radiators and boiler will work more efficiently. Debris in system water can cause cold spots in radiators and can add around 25% to energy bills. It’s also important to ensure the water in a heating system is clean, as dirty water can invalidate a manufacturer’s warranty. Power flushing, fitting a filter, and chemical inhibitors can all play a part in keeping system water clean, so we use less energy.

It’s also important to have your heating system balanced correctly so you’re not overheating rooms unnecessarily. A correctly balanced system usually means you can turn down your thermostat. By doing this by even one degree, the Energy Saving Trust estimates you can save £75 per year. Of course, there is an associated reduction in your carbon output.

The right controls are very important and can be fitted to existing heating systems for a simpler and cheaper way to reduce energy use. Weather and load compensation features are vital in ensuring your heating is operating in the most efficient way possible. Thermostatic radiator valves (TRVs) can be especially effective as you can adjust the heat in individual rooms. One thing to bear in mind when choosing controls, is that they need to be carefully matched to the boiler to ensure these features work correctly. In general, a non-proprietary heating control will not have the right software to communicate with all boilers and can only switch them on and off without that all-important modulation.

Of course, the best thing we can do to reduce our carbon emissions is to fit renewable heating technologies that work by converting the thermal energy in the environment into heat and use no gas at all. However, we should not underestimate how even the smallest measures, such as those outlined above, can help reduce energy use until these appliances are ubiquitous.

When we’re working in offices or other workplaces, we don’t have control over the heating of those buildings. However, as we increasingly work from our homes, this is our opportunity to take more responsibility for how we heat our home/workspaces. Every little change is for the better. #WhyWait?