Worcester Bosch Greenstar 25Si Compact Combi Boiler – Review

Controls

The control panel on the front of the boiler offers all the same features of a standard combi boiler, with an on/off switch, temperature settings, and an LED to display fault diagnostics. Worcester Bosch offer a wide variety of boiler controls, which range from standard room thermostats, through to smart thermostats. The most basic control you could use is a mechanical room thermostat with a dial to set temperatures, although you won’t have the accurate control over your heating and energy use. To ensure proper control of your heating, we’d recommend that you take a look at the Greenstar Comfort thermostat, or Worcester Bosch’s own smart thermostat, the Wave.

With the Wave, you’ll be able to accurately control your heating and set schedules straight from your smartphone. The Wave is also a self-learning device, which alters your heating schedules based on your everyday use of the app. You will start to see enhanced energy efficiency and improved control over your heating almost straight away. We recently reviewed the Wave thermostat here. If the Wave isn’t for you, the Nest is another smart thermostat alternative. Like the Wave, the Nest is highly intelligent and learns from your everyday use of your heating and hot water. You can also operate the thermostat through Amazon’s Alexa, using voice commands to alter your heating settings. If you’d like more information about the Nest, we recently compared the Nest to British Gas’ Hive. Take a look at the article here.

Size

Coming in at 690x390x280mm, the 25Si would easily fit into one of your kitchen cupboards, which is great if you’re looking to save as much space as possible. You’ll also benefit from the lack of hot water tank and cylinder (like any combi boiler) as the Worcester 25Si uses mains fed water on demand.

Warranty

Worcester Bosch offer a 5-year warranty with each of their Greenstar boilers, which can be extended by a further 5 years if a Worcester Accredited Installer performs the installation. An extended warranty will give you extra peace of mind in case of a breakdown or if your boiler needs a repair at any point (which is highly unlikely).

Energy Efficiency

If you’re looking for a “green” boiler, you’re in safe hands with the Greenstar 25Si. With an energy-efficiency rating of 89.8% (an A grade overall), you can expect a high-performance boiler which will save you money in the long-term. It’s now more important than ever for your boiler to be as efficient as possible as we combat rising energy prices, climate change and carbon emissions.

The introduction of the ErP Directive has meant that boiler manufacturers within the EU need to have their products tested for performance and efficiency. In order for their products to be sold to the wider public, their products need to pass certain criteria and achieve the highest possible level of efficiency. The ErP Directive will actively step in to improve the design of boilers if it’s found that they’re under-performing and wasting too much energy. You can read more about the ErP Directive here.

Verdict

The Greenstar 25Si Compact may be small but it packs a serious punch. For a small to mid-sized properties, this boiler is perfectly suitable for one bathroom and up to 3 bedrooms. Knowing that the Greenstar boiler range has won the Which? Best Buy award for 7 years running, which is a great sign of quality and promise from the Worcester Bosch brand itself, and with such a high energy efficiency rating, you have the peace of mind that it won’t break down anytime soon and that you can start to save on your energy bills from the moment it’s on the wall.