To replace older combi boiler?

[Paul Giverin]

Our non condensing combi boiler (Worcester Bosch 28CDi) is about 12 years old. It gets serviced annually and hasn't given too much trouble over the years. On its last service a couple of months ago, the engineer said that although there were no problems, it was getting on and perhaps it wouldn't last more than another couple of years.

The engineer wasn't pressurising us to buy a new boiler and I figured that we would wait until the boiler needed replacing before doing something about it but I was speaking to my son the other day and he works for Heatrae Sadia who are part of the Baxi group and he can get a very good discount on Baxi products. Coincidentally, Baxi was the preferred boiler of choice for my engineer and the 10 year warranty seems good.

So now I am weighing up the pro's and con's of replacing my existing boiler before it actually needs it. If I wait until the old boiler packs up, my son might have moved jobs and the discount would be gone. We might not be in a good position financially at that time either.

What sort of savings would I make with a new efficient condensing boiler over my older non condensing one?

Cheers,

[Ash Burton]

Keep your old boiler as long as you can.

[Dave Plowman (News)]

If you intend fitting the boiler yourself, then any savings in cost to buy it will be passed on. If you get a plumber to fit it, he is going to want his 'profit' one way or another. And if you supply the bits, he isn't as responsible if anything goes wrong.

Depends on how much gas you use. I bought a Viessmann from Ebay at well below the local prices, and fitted it myself. Paid for itself in approx 4 years over the previous RS cast iron lump. But my gas usage is higher than average.

[David]

Cynical of me, but I think the incentives to buy a Baxi may be because they are not a market leader (possibly for reasons).

We fitted a WB combi in 2005-2006 and last I heard it is still going strong with no problems. This was condensing IIRC, with the condensate pipe feeding into the back of the upstairs toilet. Similar age to yours as far as I can tell.

Daughter fitted a Baxi a couple of years later because her local plumber supplied and serviced them and it crapped out big time and has since been replaced. Silly girl didn't have it serviced annually so didn't get a warranty claim. Having said that we didn't have the WB serviced annually and didn't need to claim on warranty. From my very limited experience boiler installers tend to specialise in one model because it is easiest to just learn one system and carry one set of spares. So the "preferred supplier" is often the one most convenient for the installer.

Are you sure the 28 CDi is non-condensing? My GoogleFu isn't working particularly well but I thought that range had been condensing from at least the turn of the century.

Anyway, I would expect the boiler to have a decent life left in it, but if it is really getting long in the tooth then a 12 year record of reasonable service with at least another 2 years life (14 years+) seems to me to be more of a recommendation than a 10 year warranty.

On that basis of personal bias if I were going to replace the boiler (on the basis that if I ran it until it failed I might not then be able to afford to replace it) I would be tempted to replace like with like.

Cheapest is not always best, neither is a bargain always one. BTDTBTS.

Cheers

Dave R

[David]

Chasing up on non-condensing.

"In 2005 it became illegal for anything other than a condensing boiler to be installed in the UK (unless special permission has been granted under certain exemptions)."

So my arithmetic suggests that it is (possibly significantly) over 12 years old or is a condensing boiler.

Unless, of course, you had an exemption such as replacing an older boiler where a condensing boiler wouldn't fit.

Do tell. :-)

Got me intrigued now.

Cheers

Dave R

[John Rumm]

Here are the details for the 28Cdi:

Its not a condenser...

[John Rumm]

Then again it might go for several more... not much point in replacing it unless you need to IMHO.

There are always deals to be had of one kind or another.

Given the old one was one of the more efficient non condensers available, you could probably go from perhaps ~80% on the current one to ~90% on a new one. So not enough to be worthwhile unless you have huge gas bills.

[John Rumm]

That article is somewhat misleading. Its major gripe (freezing condensate drains stopping the boiler) is not a fault of the boiler at all, but entirely the fault of numpty installers, who can't be bothered to read the installation instructions. Some well known large installation and service firms seem very keen on installing boilers in unheated lofts and paying little attention to protecting the condensate drain from freezing.

Secondly it falls into the normal trap of comparing old low tech cast iron lumps with a modern condensers, noting the modern boiler is less "reliable" and then assuming it must be because its a condenser. A much fairer comparison would be between two modern boilers of similar technology levels (i.e. electronic controls, pre-mix modulating burner, fanned flue, electronic ignition etc) - where you would see comparable reliability overall.

(a 65% efficient cast iron lump is very reliable, since there is very little to go wrong. Feed it a new thermocouple every few years, brush the soot out of it, and a new gas valve now and then and it will run for decades... lobbing 35p of every quid you feed it trying to heat your garden)

[F]

But planting the seeds of doubt...?

[tabbypurr]

I'd say most of its points are wrong, but the conclusion is generally correct. Old boilers often go on for several decades, I wouldn't pay for a new one until needed.

And it's not illegal to fit noncondensers, there are specified conditions in which you can, I don't remember them though.

I always wondered how much one could improve iron lump efficiency by retrofitting a stirring fan. I don't plan to find out though.

Wb & Vaillant are the 2 most reliable brands in an unreliable market. I wouldn't recommend touching any of the others.

NT

[GB]

Buy boiler at discount, and keep it until needed?

[Mark]

that depends if it is a 28cdi RSF or a 28CDi Compact, RSF was only made upto

2002

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[Brian Gaff]

One of my friends reckons its not that they are exactly a waste of money, its more that like many modern things the higher tech and the way they are made makes them unlikely to last as long as an older model, and that servicing them actually costs more as its change this whole board kind of ethos against the just change this bit ways of old. I guess in that regard its much like most things these days, Make to a cost and don't make it last for ever or you will never make any dosh!

Brian

[Brian Gaff]

Hmm, I'd have thought by now there would be a thriving market in heat reclamation devices for non condensing boilers. Why is this not the case? Brian

[Jeff Layman]

Are you on the Gas Safe Register? Or are you considered "competent" to fit a gas appliance? There still seems to be a good bit of confusion around for anyone considering a DIY gas installation.

[David]

Details last updated in 2002, first manufactured in 1997.

If the quote about 2005 is correct then I assume that this must have been installed prior to 2005.

I suspect that WB would run down their supply if they knew they would be illegal to install in 2005 or later, but who knows.

Of course, the boiler could have been a special installer offer in late

2004. :-)

Cheers

Dave R

[Paul Giverin]

Well spotted. I had the boiler fitted in 2006...after it became illegal. It replaced an old back boiler system which had to go because it and the gas fire were taking up too much space in the lounge.

I researched combi boilers at the time and I was reading a lot of bad things about condensing boilers and their longevity wrt corrosion. I talked to my installer, who had been servicing our boilers for years and he shared my concerns about condensing boilers. He said that if I wanted a non condensing boiler fitted, he could source and fit it, no questions asked. Hope that's satisfied your curiosity ;-)

[Tim Watts]

And stay away from Alphas...

I've just put a WB 42 CDi in and I'm pretty pleased with it.

It's not the most sophisticated (no pump speed control, no weather compensation unless you sell your soul to their internet all in one system).

But it is competent, stable, very powerful (the 42kW is the hot water - I have used flow restrictor valves to the bath and given that half the theoretical winter output of DHW which still fills the bath in 15 mins or so). The idea is that when I have the shower room done, that can run and the bath can fill at the same time.

I'm told by the plumbers that WB have good parts availability when it does break.

My other option was a Viessmann - but they said there can be a lag on getting parts (like days to a week rather than mostly off the shelf like WB). However, the Viessmann boilers are better built (stainless heat exchanger) and weather comp is "add a sensor". Downsides apart from the alleged parts availability is the cost and the lack of a model than can match the 42CDi for DHW.

I should add, in my case, this was a whole new system - so I could over spec the rads to run easily within the condensing range. Most of the year, I can run with 55/45C flow/return which is pretty cool. Right now I have it set to about 64/54C which gives a fast heat up on a cold day and still in condensing mode.

[Paul Giverin]

Yes.... and it seems to have worked ;-)

[Paul Giverin]

Its an option but if the current boiler manages another 5 years, I don't want the new one kicking around the shed for that time and if when I do need to fit it and there's a problem, Baxi might not play ball with the warranty.