In article .com,
"Martyn Pollard" writes:
Ed Sirett wrote:
I thought there was a condensate over flow detector (there is one on
the
C40 for sure) -- just checked -- not on the C25.

I'm sure they've modded units built this year to include a level switch
on the condensate trap.

Mine, which is 2.5 years old IIRC, has a detector in the
condensate trap. It is after the U-trap part, so it will only
detect condensate blockage external to the Keston. If the U-trap
blocks with debris, or if the heat exchanger drain blocks as mine
did, the condensate won't get as far as the detector in the trap,
and won't trigger that fault detector.

Out of interest, I've never 'primed' the condensate trap before. Is it
necessary, as within a 30 minutes its full. As you say, when the flue
is inaccessible, its not possible anyway.

Has anyone seen the 'judder' starting issue with the C25? Don't know
the exact cause, but Keston have a retrofit that appears to cure it. If
I get a report of this noise I just refer it direct to Keston and they
send an engineer out.

Several people have reported vibrations like you would get from
a 32' organ pipe. I suspect this is either combustion oscillating
back up into the pre-burner area or maybe an undamped feedback
loop in the venturi gas valve. I had this on initial installation
as the preset mixture adjustment was preset incorrectly.

I'd be interested to know what others use as the jointing compound
between the flue spigot to the flue pipe.

I solvent welded it. However, my flue spigot turned out to be
faulty (Keston's weld between the stainless steel and the muPVC
collar wasn't water tight). I broke it apart (at which point you
could see why -- the glue they used hadn't gone all the way round),
and remade it myself. I roughed up the stainless steel and used
a ring of solvent weld around the lower 3/4 of the area, and
used a special acid-resistant high temperature silicone sealant
in the top 1/4 to preserve the water seal even if the solvent
weld didn't seal to the stainless steel.

When that had all set, I then solvent welded it to the muPVC
flue as before.

I also used a non-setting sealant on the exhaust spigot gasket.
(Initially I had thought that's where the leak was. However, it
turned out the leak was in the manufacture of the flue spigot.)

Having had a leak, after I had fixed and reassembled it, I left
the garden hose running slowly into the flue terminal for perhaps
half an hour to be double sure there were no more leaks in the
condensate path. Leaks of condensate will rapidly wreck the boiler
as someone else reported here a while back. If I ever fit another
Keston, I will do this check with the garden hose as a matter of
course as part of the commisioning procedure.

--
Andrew Gabriel