Back boiler

[AndWhat]

Our central heating runs through an old back boiler system. It works fine but I have been told by A British Gas engineer we should replace it for a new Combi style boiler sooner rather than later and gave me a huge quote for a new system.
Has anyone replaced their back boiler? I don’t see a reason to replace whilst it works. Plus I don’t have the cash to replace so I would have to lend the money which adds to the cost.

If it works then I would leave it.

We replaced ours but that was because the fire attached to it had broken and we wanted a new fire. If nothing was broken we would have not replaced.

If you do replace shop around for quotes.

Don't assume that a Combi is suitable for you (though it is quick, easy and profitable for the installer).

How many people live in your house, and how many bathrooms? The ideal number for a combi is one, and they get less suitable as the numbers increase.

A combi is rather slow to fill a hot bath, though it can probably give a decent shower as long as no-one else turns a tap on.

Fill a bucket at your kitchen cold tap (and garden or scullery taps if you have them), time it, calculate how many litres per minute you get. This is important.

There are 2adults and 2 children. We have 2 bathrooms. 1 has an electric shower in the other has a bath (which the children use)
I will time the taps over the weekend - what sort of times should I be looking for?

12 lpm is the minimum to give a worthwhile shower.

Consider that a bath may contain 100 litres of water. It's wearisome to have to sit reading a book while it fills up.

If you have traditional UK bathtaps (which have large waterways) and 22mm pipes from your tank, I would hope it currently fills faster.

I'd consider 20lpm to be really good, and enough to run an unvented cylinder (which gives unsurpassed hot water) but an old house may need to run a new pipe out to the pavement to get it.

We replaced our back boiler with a combination last year. Think it was in the region of £2k, to rip out back boiler and hot water tank and valve all the radiators.

Tbh I think we've recouped some of that already in efficiency. The back boiler was noisy and clearly inefficient, even if a complete workhorse - it functioned perfectly for 25 years!

modern boilers are more efficient than old ones, certainly.

But it is a mistake to think that a modern combi is as efficient as a modern conventional.

If your boiler is working and you're happy with it, you probably don't need to replace it.

The only thing I'd suggest is a carbon monoxide detector (which beeps, not just changes colour) next to it in case something goes wrong - the very elderly cooker in our previous (rented) house started giving off carbon monoxide, and I'm very grateful we knew!

Whatever you do keep away from British Gas. They are overpriced and always trying to flog you new things. Use a local trader

I just had a boiler replaced and the British Gas quote was a thousand pounds higher than the reputable local trader. If you do go ahead, make sure you get quotes - I’d be very surprised if British Gas were in any way competitive although it can be useful to get a quote from them as they generally seem to know what they are doing which helps show up the cowboys (British Gas and the firm I went with both explained why I could only have a boiler up to a certain gas flow. They gave the same reasons based on inspecting the gas supply in the basement of the flats. Another company didn’t bother to check the supply and tried to sell me a significantly larger boiler).

In regard to the type of boiler, I got a combi and I love it but I am in a very small flat and don’t use much hot water a day (and never take baths). If you already have an electric shower and the combi only has to do one bathroom you might be OK but you might want to also look into a conventional system with a hot water tank to see if that would suit you better.

In regard to replacing it, did the engineer give any particular reason? I generally agree with leaving well enough alone if it’s working OK but not if that means it’s going to break down in December.

Also, there can be other reasons. Mine still worked but I wanted the space (a large cupboard where the tank was) and more importantly, the flue was legal when it was installed but no one could work out where it vented to the outside (the fitter who took the old boiler out who got a good look said to the roof and therefore through at least two other flats) which means it couldn’t be inspected and every time it was serviced I got told it was ‘at risk’ and they gave me a form saying they advised I stop using it and was aware continuing to do so was at my own risk. I got tired of worrying about it even with a carbon monoxide detector.

We had to get a new boiler in January as our old oil boiler packed up. Everyone I spoke to said avoid combi boilers at all costs.
As it happens we have a stove with a back boiler so often have a surplus of hot water, a conventional boiler can be plumbed into it and use tha surplus.