Lifespan of a condensing boiler?

[Dave W]

I don¢t agree at all, insurers are looking to cover the risk involved over the next year. A 15 year old conventional B/F boiler probable only has a gas valve and a thermocouple that are likely to fail. A 5 year old condenser will likely have fan, gas valve, thermistor, flow sensor, ignition electrode, flame detector, fan stat, safety stat, and probably at least two PCBs. We will have to wait a few years to see if current combi that everyone seem to be buying are as reliable as you think, but with ever more bits inside to go wrong I cant see it.

[IMM]

So would a regular system boilers too. There is not that much differnce in control parts in either boiler types. The better condensers have downward firing burners and one piece heat exchangers, unlike the crocks the UK heating industry previously turned out. Some are guaranteeing their stainless steel heat exchangers 5 years.

I think you mean condenser not combi. Well they are reliable enough in Germany and Holland...and...GlowWorm are owned Vaillant and have many Vaillant parts inside. The Germans bought Worcester and called it Worcester Bosch.

[raden]

In message , IMM writes

No, exactly the same size, even down to the positioning of the stand-off holes

Well you of all people (cough) should know that doing that would lay you right open for installing the wrong pcb

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[raden]

In message , G&M writes

So if they sell a faulty part which hasn't been tested, which, e.g. opens the main gas valve before the pilot valve has been lit ?

Not even close ...

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[IMM]

So 6 pcbs all the same size, doing the same thing with different opart Nos? How odd. But I'm sure different prices.

But they are all the same according to you, so yiou can't fit the wrong one.

[Andrew Gabriel]

Yes, wasn't a serious suggestion.

If you consider a more expensive item which you expect to last a lot longer than 10 years, this issue is a real problem. Some 10+ years ago when I was working on System X, the components used in that were going obsolete at the rate of around 2 per week IIRC. You have to maintain a redesign team in that case, just so you can carry on making line cards and other parts, for a system which has a design life of decades.

[raden]

In message , IMM writes

But different part numbers, so no, from an insurance point of view

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[G&M]

Why should it change it's functionality just because they change a faulty part. Does your car run backwards when you change a dead spark plug.

Really ? Look at the standard SEMI MTBF charts then.

[IMM]

writes

But "technically" the same thing.

[raden]

In message , G&M writes

When you spend your days repairing boiler PCBs, you don't need to look at charts to tell you the faults.

as I said .. in the real world

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[Mary Hinge]

15 years ago you wouldn't have found a PCB in a car engine compartment either, yet today they are commonplace and as a result cars are more reliable and efficient.

A PCB in a harsh environment not necessarily a problem provided sufficient care is taken in 'hardening' it. Also a modern non-condensing boiler will have most of the additional components you listed.

So that's you sussed then ;o)

MH

[Dave Plowman (News)]

You're joking? EFI dates back to the late '70s. Although a sensible maker might well keep the electronics out of the engine bay anyway.

[G&M]

So what parts do you find die most often ? And is the information fed back to the manufacturers to stop them carrying on using a faulty design ?

[G&M]

20 years perhaps. After the early mechanical GTi's most changed to electronic quite soon.

Not sure on the "more reliable" bit though as the owner of any 'posh' Land Rover (i.e. not the real ones) will tell you.

[Andrew Gabriel]

Design life of a car is of the order ~3000 hours, and you don't need any hardening to get designs based on standard commercial grade components to last significantly longer than that (besides the obvious waterproofing, etc). The control gear in a compact fluorescent lamp uses components running above their specified ratings, but since they only have to last 10000 hours, that's fine too.

You'll be rather disappointed if your boiler only lasts 3000 hours because, you'll probably need a new one under guarantee. You'll be even more annoyed if it only lasts 10000 hours, as that would probably be a failure within a few years of fitting but outside the guarantee.

Kind of a different order of magnitude.

[Andy Wade]

This reminded me of the craze for homebrew CD ignition systems in the

70s. I ran a Mini with a version of the Practical Electronics CD ignition design from... must have been about '74. That's twice the aforesaid 15 years ;-). This was also about the time when the motor industry realised that if they would have to take EMC RF immunity issues seriously.

[IMM]

I installed a contactless electronic ignition unit in a Merc sports car 30 years ago. The idling immediately stopped hunting and the acceleration increase was noticeable. It started first crack each time.

[Ed Sirett]

Yeah right. Like they would want to know. The only time the makers would listen is when the design is so truly abysmal that they have a warranty issue.

[G&M]

Having in the past as an R&D director with a fairly well known electronics company sat down for several days each quarter with the Q&A manager to get on top of field reliability problems I think you will find those makers do want to take note of the failures, though obviously attending to individual complaints is much harder. But service centres and suchlike are a prime source of good data for reliability analysis. It isn't just a case of warranty issues, a reputation for dying after 'n' years is just as damaging as people start believing you've actually designed it to be so.

[G&M]

I built one of those for an Escort Mexico rally car. One transistor went pop at almost 7500 rpm. Hadn't thought about stress levels back then.