Energy Efficiency - Penny Wise Pound Foolish?


If you have gas central heating, did you know that your boiler is the single largest consumer of energy in your house? They typically use anywhere between 12kW of energy for a small wall mounted boiler, right up to 40kW for some large capacity combi boilers. So here we will give you the facts and figures and you can see for yourself whether or not you will save money by changing your model foor a newer more efficient one.

The efficiency guide


The chart you can see here is the SEDBUK chart for ranking boilers in order of efficiency. The Seasonal Efficiency of Domestic Boilers in the UK rating scheme was developed in conjunction with boiler manufacturers and the government and provides a fair comparison of average boiler efficiency.

So, what does this all mean for you?

Your boiler will fit somewhere in this scale, if its towards the bottom it's bad, if it's towards the top it's better, quite self explantory?

Most older boilers generally fall into the bottom two categories, whereby the technology from 15 years ago and beyond was focused on keeping things simple with few controls and moving parts, energy wasn't as much of an issue as it is today.

Check you boiler efficiency here

Pounds Shillings and Pence


Lets look at things realistically with some number crunching. My boiler is a G rated boiler, 65% efficiency, so for every £1 of gas I buy from my supplier, I am only getting 65p worth of useful energy. If I was to change it for an A rated appliance at 92% efficiency, I would be 27p in the pound better off. Its easy to see that a fair amount of money can be saved by changing my boiler

Out with the Old?


Where does the energy go on old boilers? Heat is wasted in many ways on older style boilers, some but not all include;

  • Pilot light running all the time
  • Heat loss through conduction- case on boiler getting warm
  • Heat loss via hot gases going out of flue when in operation
  • Poor system design - such as gravity circulation, inadequate controls on heating

Technology has increased amongst boiler manufacturers immensley over the last few years to bring the efficiency ratings higher and higher. The pressure is mounting globally to bring Carbon Dioxide emissions down, and consumers are feeling the pinch with rising energy bills.

If you have an old boiler with a very low efficiency rating, E,F of G, it is definitely worth while changing your appliance for an up to date model, the sooner you do then the sooner you will be saving on your energy bills.

However, if you have a D rated boiler, the decision to change on gas savings alone are not so justified, as you will only be saving about 10% from your gas consumption. You may wish to look at other alternatives for the time being, such as upgrading to a digital room thermostat, or having thermostatic radiator valves fitted on your radiators. Having a system with up to date controls will save you on money as well as making your house more comfortable.