Heating accounts for about 55% of what will be spent each year in energy bills, so an efficient boiler makes such good sense.  However, there are other considerations such as the fuel type.  Currently mains gas is the cheapest heating option compared to oil, electricity (even economy 7), LPG and coal or other solid fuel.  No gas?  Then you can look at connection to the mains.  You could also consider renewable or low carbon heating such as a heat pump or biomass.

Why is it green?

As heating makes up over 50% of the household energy bills, looking at your boiler and seeing if a new one makes more sense is a good idea.  A new condensing boiler is upto 90% more efficient than an older models. 

What’s involved?

Most older systems have a separate hot water cylinder and a header tank, and you may decide to keep these and just change the boiler.  However, there is also the combi boiler which produces heat as required and doesn’t have a hot water tank.  This requires more radical adaption of the building (at a higher cost).  The regular boiler is more efficient, but has to store hot water which then loses heat.  If you use hot water regularly a regular boiler and tank is best, for smaller households, then a combi is best.

Can you DIY?

Definitely not a job for a DIYer.  A new boiler must be installed by a qualified fitter, and if gas, by one who is on the Gas safe register.

How much does it cost?

A new boiler fitted will cost about £2,500 depending on type and labour costs.  This would be for an energy efficient boiler.

Does it save money?

An energy efficient boiler could be expected to save you about £250 a year.

Can it be done in a church?

It can, and here, when the need for heating and hot water is sporadic a combi boiler may be of more benefit that a regular system.

Other Thoughts?

Combi boilers work on a higher pressure on the pipes than a regular system, so if thinking about a Combi, pressure check your pipes first.  Combi boilers are not compatible with solar heating.  Corrosion deposits in older systems will cause a substantial reduction in heating efficiency and the radiators.  Scale can also reduce efficiency in heating circuits.  Speak to an engineer about having a ‘power flush’ to clear the system and use a chemical inhibitor to stop build up.  This should cost about £300, cheaper than a new boiler, but may make the whole system more efficient.