In message , Ian
Stirling writes
Andrew Gabriel wrote:
In article ,
"JJJ" writes:
A plumber just told me that you're lucky if you get more than 10 years out
of a condensing boiler - because of their complexity and the fact that the
condensate rots them from the inside out...

is he right?

I suspect so. The earlier ones didn't last that long,
mainly failures due to corrosion. Current ones should be
better in this respect.

The high tech microprocessor/microcontroller boards used
in them won't be able able to be made in 10 years time
when I would expect many to fail. Most of the components
will be long obsolete and no one will redesign a board to
use modern components just for the spares market. The life
of the units will be limited by the quantity of up-front
spares manufacturers stock, and it really isn't in their
interests to do this. (and what Geoff gets working again.)

It's pretty much at the point that this could almost be irrelevant.
You design a generic board, with plenty of sensor interfaces, relay
outputs and stuff.
You then plug this into a board with connectors for the original
plugs, and your generic board.

This might be a bit more expensive for OEM, but should be fine for
spares.

The interface board connects up some connectors that are mandatory, for
example, if it has an overheat stat that should shut off all bar the
pump, that's hardwired.
Everything else is done in software, loading a profile of the correct
boiler.

Great in theory, but it just doesn't happen. The closest to a "generic"
board anyone seems to have got is the Honeywell sequence boards which
fit directly onto gas valves, but even then none of them are quite the
same and there is the rival Italian company SIT who are in competition

You only have to look back a few years when Glowworm had (still have) 6
pcbs which are identical in operation and totally pin compatible, all
very different in design.

While I've often wondered why, and sometimes thought of designing a
generic boiler control PCB, manufacturers are showing no signs of
unifying at all or having any intention of doing so


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--
geoff