Are Worcester Bosch Boilers Energy Efficient?
Worcester Bosch are one of the most well-known boiler brands in the domestic heating industry, but how energy efficient are they really?
Worcester Bosch are one of the most well-known boiler brands in the domestic heating industry, but how energy efficient are they really?
If you’re considering investing in a Worcester Bosch boiler, you will inevitably want to make sure it delivers on quality, efficiency and reliability.

How efficient is a Worcester Bosch boiler?
Worcester Bosch pride themselves on creating energy efficient boilers, with popular ranges like Greenstar and Lifebeing ErP A-rated and 91-94% efficiency.
All modern Worcester Bosch boilers are made with aluminium heat exchangers, making them effective and efficient, with over 90% of the heat produced being recycled.
Worcester Bosch boiler efficiency ratings
The condensing boiler technology that Worcester Bosch uses has seen them lead the way when it comes to high efficiency boilers.
With an extensive range of different boiler types, including combi,
regular and system, the Worcester Bosch Greenstar models are designed to help lower the carbon footprint of your household and keep your energy costs down.
In fact, these boilers have won several awards thanks to their low CO2 and NOx emission levels, making them much more environmentally friendly than many other boilers on the market.
While many Worcester Bosch models are designed to be 94% efficient, the Greenstar range is known for its high energy efficiency that converts 97% of gas into consumed heat. By adding the brand's Bosch Easy smart thermostat, you could reach an impressive 98% efficiency.
The best Worcester Bosch boilers for energy efficiency
If you think your home would benefit from a Worcester Bosch boiler, it’s a good idea to take a look at some of their most efficient models so you can decide which is the best for you.
Worcester Bosch Greenstar 8000 Life
The Greenstar 8000 Life is a modern combi boiler that combines cutting-edge technology with a sleek design, making it a great choice for modern homes.
This boiler boasts a high seasonal efficiency rating of 94%, making it an ErP A-rated boiler. It also has an output of 30kW, making it ideal for medium sized homes with up to 20 radiators. It is also compatible with the Bosch Easy smart thermostat, allowing for easy control and monitoring of your heating system.

Worcester Bosch Greenstar 4000
The Greenstar 4000 is another modern combi boiler by Worcester Bosch that boasts an impressive 94% efficiency and ErP A-rating for both heating and hot water.
This boiler can also modulate its output, meaning it can reduce its power output to as little as 10% of its maximum output during periods of low demand. It also features a ‘Quick Tap’ function that minimises water waste by reducing the time it takes to get hot water from your taps.
Worcester Bosch Greenstar 2000

If you have a small-medium sized property with not much space for a boiler, the Worcester Bosch Greenstar 2000 is a great choice. The Greenstar 2000 comes in 25kW and 30kW models and both are known for their compact and energy efficient designs.
Both models come with a 94% energy efficiency rating, with an Erp A-rating. They are also compatible with many smart thermostats, not just the brand's own Easy smart thermostat.
Worcester Bosch Greenstar 1000
For smaller properties with limited space, the Worcester Bosch Greenstar 1000 is a great space-saving solution without compromising on quality or performance. These compact boilers are ideal for small homes and flats, while still delivering excellent energy efficiency.
Despite their small size, these boilers have an efficiency of 94% and an ErP-A rating. Their intelligent controls also make these boilers perfect for homeowners who are looking to incorporate advanced features and intelligent controls into their heating management systems.
Can you improve the energy efficiency of a boiler?
There are a few different ways you can improve the energy efficiency of your boiler and we’ve listed our top tips below.
Regularly service your boiler
You should treat your boiler how you treat your car by regularly servicing it to keep it running safe and smoothly.
At Lacey Plumbing & Heating, all of our engineers are Gas Safe qualified and can work on all types of boilers, including Worcester Bosch. Our boiler servicing includes a comprehensive check of your boiler, including any repairs that may be necessary to keep things running smoothly. We even have boiler service plans that give you priority access to our trained, insured and professional engineers.
Keep your boiler clean
Although this isn’t an obvious cleaning job, keeping your boiler clean will pay off in the long run. By cleaning the boiler yourself, you’ll help to prevent the tubes and pipes from becoming clogged, which can hamper its performance and therefore cause higher heating bills.
To prevent dust from settling on your boiler, you should give the outside of it a once over whenever you clean your house. It’s important you don’t try to clean the inside of your boiler yourself as this will be conducted professionally by one of our engineers.
Bleed your radiators
Bleeding your radiators is an easy maintenance task that can help to improve your boiler's efficiency and keep bills low too.
To determine which radiators need bleeding, you should fire up your heating and see if any of the radiators take a while to heat up or have cold spots.
You can check out our guide to bleeding radiators to find out more on this topic.
Top up the pressure
A drop in pressure in your boiler can really hinder its efficiency. Thankfully, it is very easy to correct.
Checking the pressure gauge on your boiler will help you to know if your boiler needs topped up. It should read at around the 1.5 bar if the pressure is healthy. If not, then it’s time to top it up.
You can find out more on topping-up your boiler by reading our guide on understanding boiler pressure.
Insulate your pipes
Insulating your pipes can help to reduce heat loss and keep your water hotter for longer.
Most DIY stores will stock lagging, which are foam tubes that you can wrap around pipes. Just make sure you know what size you need.
Upgrade your boiler
If all else fails and you think it’s time to upgrade your boiler, our team can help.
Our boiler installation services are ideal for homeowners who are looking to upgrade to modern, A-rated boilers, including all the Worcester Bosch models we have discussed in this guide.
Our team at Lacey Plumbing & Heating are trusted professionals that can take care of your boiler installation, service and repairs. For more information, you can complete our free quote or get in touch with us today to discuss your boiler and heating needs.