Are New Boilers More Efficient

Are new boilers more efficient than my current boiler? Chances are yes. But that depends on a few things. If your boiler is an old-style heavyweight boiler. And you are replacing it with a modern condensing boiler. Your annual saving will be on average £652 a year (source: Sedbuk)


All modern condensing boilers have an efficiency level between 89-94%. Older non-condensing boilers can be as little as 60% efficient. 40p of heat out of every £1 of gas burnt is a lot of wasted energy!


Which are the most efficient boilers?

The Viessmann 200 Combi boilers are up to 98% efficient


Worcester Bosch combi boilers are up to 94% efficient


Vaillant Boilers up to 94% efficient


Ideal and Baxi are up to 89% efficient


All boilers must have an ‘A’ rating with factory tested efficiencies of 89% or higher. In the real world, these levels are rarely achieved. The boiler is just one component in the overall heating system. The whole system must work effectively for the boiler to achieve 90% or more.


Ensuring maximum efficiency is achieved

  • Have a low minimum output.


All modern boilers have modulating burners. A modulating burner is one that can reduce its output to suit the demand placed on it. The lower the minimum output of a boiler the more efficient it can be.


Imagine you are driving a car down the motorway at 70mph. Older boilers can only put their foot flat to the floor, or off the pedal completely. A modulating burner can see that that the speed is approaching 70mph. And ease off the gas and allow the engine to work at a lesser rate to maintain the speed.


  • Be sized correctly


Most UK homes, need on average 6-8kW on a very cold day and even less the rest of the year. Yet most boilers far exceed this on their heating capabilities. This is why it’s important that the maximum output of the boiler is rated down to suit the property it will be heating.


You may be asking yourself why do you need a 30kw combi boiler if you only need 6-8kW to heat your home? Combi boilers are designed to supply instant hot water to your taps at different flow rates. This is where the full output of the boiler is used.

  • Be paired with compensation controls


Modern boilers can modulate their outputs to suit the demand as we have already discussed. But to get the most out of your boiler you need to pair it with compensated controls. This can be Load or weather compensation


Older technology when it comes to boiler controls simply have two commands to tell the boiler; heating on/ heating off.


A modulating boiler control is the most efficient way to control your boiler. Modulating controls have the ability to talk to your boiler other than the basic on or off command.  When a modulating control recognises that your room is near the desired temperature. It will modulate the boiler down to a lesser work rate.

Saving money and keeping higher levels of comfort in your home. Reducing the radical temperature swings