Replacing an old gas boiler......if not now , then when??

Jalma

My Mum has a wall mounted room-sealed Baxi that is now 43 years old. In that time it's had a couple of themocouples, two gas valves and a thermostat. Pretty much all the parts are still available. Efficient it certainly isn't, but it's difficult to make a financial case for changing it. I reckon a modern condensing combi would save her around £200 per year on gas.

It was originally on a British Gas service contract. They started advising her to replace it when it was 10 years old as "parts are getting hard to find".

As molerat said above, there is a lot of carbon generated by replacing a boiler, and I'd wonder what the lifespan of a new boiler is. I don't see our Ferolli making it to it 40th.

[Deleted User]

A relative had a Worcestor-Bosch, it lasted 7 years. Then, a Baxi, which lasted 6 years.

I've a Biasi (defamed by many) which is now 17 years old, and still going strong. I've never spent a penny on it!

As previous poster said...

Also, for a condensing boiler to actually be more 'efficient' than a 'regular' boiler, all the planets have to be in alignment

Verdigris

Also, for a condensing boiler to actually be more 'efficient' than a 'regular' boiler, all the planets have to be in alignment

No, you just have to have your system correctly balanced to ensure the return water is at as low a temperature as possible.

oldagetraveller1

"The tree huggers"

Don't use that description in the Motoring board. 

A certain individual there will be very offended and call you a dinosaur!

[Deleted User]

Verdigris said:

No, you just have to have your system correctly balanced to ensure the return water is at as low a temperature as possible.

Oh really?

So, the multiple times a day, when one of your TRV's turns off, cos that room has reached correct temp, and now your return is too hot?

Or, your radiators aren't big enough to handle a condensing boiler to start with?

You'll probably save about 2p a year.

merchcon55

This is very interesting comment - a few years ago we were considering replacing our "dinosaur" inefficient boiler. We were advised at the time that not only should we change the boiler, but all the older radiators as they simply would not be good enough for the newer boiler. He said you are going to need much larger radiators - that's just how these newer boilers work.

At the time I thought they were just trying to flog us new radiators - so now I know that was not so porky pies.

Both my wife and I have always worked from home - not just since the pandemic - so it was always hard to really compare our gas bills to our friends, who simply were not home as often. We considered it a cost of doing business, as we were not paying any added rent for offices.

Of course in the past year, everyone we knew was working from home - so I recently asked a few friends for their usage figures for the past 12 months - those who had similar size and age houses (ours is 1920s).

They all have considerably new boilers.

Well our usage was on average, only 10% more than 8 of our friends. And in 2 other cases, they used more than us. 

Of course I cant know for certain how many hours each house had the heat on each day - but I would have expected a similar amount given we all work similar hours. 

It's just a small sample size of course, but perhaps the cost savings people are made to believe are not anywhere near as much as they think - factor on top of that the average boiler lasting only 10 years. Not to jinx ours, let's just say it's a lot older than 10years old.

matelodave

It really isn't ever so hard to do some simple sums.

If you use 12,000kwh of gas a year and your superduper new boiler saves 10% then you'll only use 10800kwh. Lest assume the worst cae of 5p/kwh for gas then your existing bill of 12,000 x 5p = £600 and your new one will be £540, thus saving you £60 a year. Be generous and give yourself a 20% saving = £120 a year.

Divide that into the cost of a shiny new boiler,(including installation) say £1800 then even with a 20% saving you'll just about break even after 15 years - assuming that nothing has gone wrong.

Whichever way you work it out IMO you'll be better off waiting until the boiler has gasped it's last before changing it for a new one.

alanwsg

matelodave said:

Whichever way you work it out IMO you'll be better off waiting until the boiler has gasped it's last before changing it for a new one.

We had an ancient (40+ year old) gas boiler, that thumped and crashed when it was on and went through a thermocouple every six months or so. Had the whole system replaced - boiler + rads + pipes in July for around £5K.

What convinced me to go ahead was..

1) For the last 3 or 4 winters, I've been terrified the boiler would finally  "gasp it's last" in the deep mid winter when CH installers were impossible to find and fully booked There are a couple of parts on it (gas valve, heat exchanger) that can no longer be found anywhere, so a catastrophic failure was on the cards sometime.

2) Once you realise it will have be replaced sometime anyway, you might as well go ahead ASAP. You'll get the savings of a more efficient boiler, even if they won't ever cover the full cost. And you don't spend the winter worrying about it. And you can schedule the work in the summer. And the cost of a new boiler is only going to go up the longer you leave it.

Mister_G

My LPG Baxi back boiler is coming up to 38 years old.  In that time all it's had is a new thermocouple for the FFD and a new gas valve - total cost £50.  Parts are still readily available at a sensible price.

There's no expensive unreliable PCB to go wrong.  It may only be 65% efficient, but certainly not worth replacing until it becomes unrepairable.

Verdigris

I'll be moving to a house with a 30+ year old Worcester LPG balanced flue boiler. That's coming out, along with the radiators, and underfloor heating and a heat pump are going in. External insulation will be added to further increase fuel efficiency to around 400%.