Energy Efficiency Hacks for Unvented Cylinder Owners

Your unvented hot water cylinder is built to deliver strong, consistent water pressure and to refill and reheat fast. However, like any system, its efficiency depends on how well you maintain it. A perfectly functioning cylinder heats water with very little waste. One that isn’t maintained can quietly drain your wallet through higher energy bills, wasted water, and premature wear.

The good news is that a few smart habits and simple checks can keep your system running at peak efficiency and save you money.

Keep Your Combination Valve Clean and Healthy

The combination valve regulates incoming water pressure, prevents backflow, and filters out debris to help protect your cylinder.

If those filters get clogged, the water flow into your cylinder slows down. That means it will take longer to heat water and use more energy per litre of hot water. A leaking combination valve is even worse. You’ll pay to heat water that never reaches the tap.

Efficiency hack: Ask your G3-qualified engineer (EasyFlow) to clean the valve filters during your annual service. If you live in a hard water area, consider adding a scale reducer.

Check Your Expansion Vessel’s Pressure

Water expands when it’s heated. The expansion vessel absorbs the extra volume of water created when it’s heated. If the air charge inside drops too low, your cylinder will push water out through the relief valve each time it heats.

Every litre discharged is hot water you’ve paid to heat, and now you’ll pay again to replace it. Over time, this constant pressure cycling can also stress your valves and heating elements.

Efficiency hack: Have your engineer check and recharge the expansion vessel’s air pressure annually. A simple pump-up could save you a lot of energy over the year.

Keep an Eye on the Tundish

A dripping tundish is both a maintenance issue and a sign of wasted energy. Even a slow, steady drip can add up to hundreds of litres of hot water lost over months.

Efficiency hack: Check the tundish weekly. If you

Insulate and Optimise

Modern unvented cylinders have built-in insulation from the manufacturer, but the surrounding pipework can still lose heat. That means your system works harder to keep water at the right temperature.

Efficiency hack: Insulate exposed hot water pipes, especially between the cylinder and frequently used taps, like in the bath or kitchen. You’ll keep water hotter for longer and reduce reheating cycles.

Service Before It Costs You

An annual servicing for your safety, but it’s also designed to make sure your cylinder’s working correctly. Cleaning filters, checking pressure, testing the thermostat, and inspecting safety valves all contribute to more efficient operation (and less wasted money).

Efficiency hack: Book your service before the colder months hit, when you’re using more hot water and efficiency matters most.

A More Efficient Future

Efficiency goes beyond having the latest technology. The goal is to keep every part of your unvented cylinder working as intended. By giving a little attention to your combination valve, expansion vessel, tundish, and insulation, you’ll cut waste, lower bills, and extend your system’s lifespan.

Not sure if your unvented cylinder is running at peak efficiency? We can help. Get in touch with EasyFlow today.