Should I replace my boiler at the same time as insulating my external walls?
External solid wall insulation is a big addition to the fabric of your home, so it is worth thinking – what else should I be doing at the same time to make sure I am getting value for money on my installation? One possible answer might well be to consider installing a new boiler!
As you may be aware, a typical boiler will have a little round vent coming out of your wall to allow the waste gasses to escape the room. The flue usually sticks out from the wall, and you will often see on a chilly day the steam rising from the side of the house.
In most cases external solid wall insulation protrudes from the existing wall by 100mm (although this might vary between suppliers). When you install external insulation, as you might expect, you can’t just bury the flue in the insulation, it needs to be extended out with a flue extension kit that exactly matches the current model of boiler. This typically adds around £200 to the cost of the works.
If you need a new boiler at the same time – you can avoid that extra cost, because the new boiler can have a longer flue installed at the same time at no additional cost. This won’t be the answer for everyone of course – some people will already have a relatively modern boiler installed, in which case it will be far most cost effective just to pay for the extension of the flue.
Older boilers with open flues
When you have a really old boiler, they quite often come with an open flue – you can normally recognise this as a big square metal box on the wall. These are a real issue with solid wall insulation because you can’t insulate flush up to them; instead you need to leave 10cm around the perimeter of the open flue. Likewise if your boiler is so old there is no flue extension kit available, then you need to leave a gap around it, which again looks pretty strange.
The best solution here if funds allow is to replace the old boiler with a new one – obviously you will also benefit from the energy savings produced by installing a new, more efficient boiler, which will make the payback on the solid wall insulation even quicker (but clearly you need to take into account the cost of the new boiler!)
When you install a boiler today, it must by law be a condensing boiler. Condensing boilers are more efficient than their older counterparts, but they have an extra pipe that needs to find it’s way to a waste water pipe – it’s called the condense pipe. The condense pipe is a little plastic tube that runs from the boiler to either the back of the sink, to a downpipe, or a drain. In many homes, the pipe will go through the external wall and run outside.
This pipe will likely have to be extended as part of the works if you are installing external insulation, but if you are replacing the boiler already, it is something the installer can take into account.
How much will a new boiler cost?
Buying a new boiler will cost around £800 at the local plumbers merchant, but the cost of labour to install it and any additional works that are involved will add to the cost, and can mean the end price ranges from £1,300 up to a few thousand. Things to look out for are where the boiler is situated – if it is on an external facing wall the cost is going to be cheaper. If your boiler is internal with an internal flue, you are going to be looking at a bigger price tag. If you are looking to convert from a system boiler over to a combi boiler the cost is going to be higher as well.
Should I install a boiler when I get my EWI installed?
If your boiler is likely to need changing in the next few years, it might be worth considering installing a new boiler at the same time. It could end up saving you up to £300 on your EWI cost, and you will end up with a brand new boiler at the same time. If you are getting your boiler installed at the moment, and are considering EWI for the future, make sure you get your flue extended as part of the works, otherwise you will incur additional costs down the line.
Please let us know if you are considering a new boiler, as Be Constructive can provide you a quote for a new boiler and EWI at the same time!