Boiler Efficiency FAQ

Q. If I change my old boiler for a new one, how much can I expect to save?
A. If your boiler was installed prior to 2003, you could save a third on your heating bills and reduce your home's CO2 emissions by 800 kilograms a year.

Q. How much can I save by reducing my heating and water temperatures?
A. Reducing your room temperature by 1ºC could cut your heating bills by 10%. Setting your water cylinder temperature to less than 60ºC and fitting approved thermostatic mixing valves will also help save money.

Q. Are there now more sophisticated ways of programming heating than a thermostat and timer?
A. Yes, more intelligent heating controls are now available that can increase your comfort and save energy.
 For example, wireless heat controls in every room can be re-set remotely from your laptop – very useful if the time you thought you'd arrive home changes.
 Weather compensation controls do just what they say by monitoring the outside temperature and the room temperature using Vaillant’s VRC 400 or VRC 430 controls and then adjusting the boiler to achieve the required heat output. On a sunny day, for example, the heat output from the boiler will be reduced, as a result radiators may feel cool to touch.

Q. I’m extending my home – will I need a new boiler for the new section of the house?
A. The capacity of your existing boiler will have been matched quite closely to the size of your home – the floor space and the number of bathrooms – in order to achieve maximum efficiency. If you are just adding one radiator for a new conservatory you will not need to replace your boiler, but if more radiators and hot water are required you should contact a heating adviser to find out if a new boiler is needed.

Q. What are the advantages of installing unvented hot water cylinders?
A. As well as being more efficient, unvented cylinders use mains water pressure supply. This means there is no need for a cold water storage tank, which will give you more room in your loft.

Q. How are high-efficiency condensing boilers more efficient than standard efficiency boilers?
A. High-efficiency condensing boilers are able to capture and use much of the heat that old non-condensing boilers waste and release into the atmosphere.
 Condensing boilers convert around 90% of fuel into useful heating, whereas old conventional boilers only convert around 60% and waste the rest. All new gas boilers in England and Wales must be condensing boilers.
 ISEDBUK (the Seasonal Efficiency of Domestic Boilers in the UK) rates boilers A to G according to their efficiency – band A is the most efficient and band G the least. All Vaillant boilers are rated SEDBUK A.

Q. Is my new boiler environmentally friendly?
A. The boilers in Vaillant’s current range are amongst the most environmentally friendly you will find. Due to low NOx (nitrogen oxide) emission and high efficiency they pump out less C02 than older models. Plus, none of the materials used to make them contributes to the Ozone Depletion Potential and the Global Warming Potential (see below).
 The Ozone Depletion Potential (ODP) is a number that refers to the amount of ozone depletion caused by a particular substance. All Vaillant boilers have an ODP rating of 0.
 The Global Warming Potential (GWP) is a measure of how much a given mass of greenhouse gas is estimated to contribute to global warming. Vaillant’s boilers have an official rating of 0 in this category.

Contact Details

Simon Mason 

mobile - 07783146897
landline - 01733 755667 
Energy Efficiency Qualified - Part L - Heating Engineer
Gas Safe Register has now replaced Corgi Gas - the regulator for gas engineers