"Keith" wrote in message
...
I

I wrote:
My Ariston Eurocombi Boiler has developed an intermittent fault, where
it shuts down (flame goes out) for a second or so, then fires back up
again,

Fault finding suggests an intermittent fault in the boiler output limit
thermostat, and temporarily bypassing the 'stat restores normal
operation,

You followed up:-

Try by-passing the thermostat and firing the boiler up to see if it holds
on
properly. If not, then it isn't the 'stat that's at fault.

It certainly seems like the stat is at fault, but I don't want to run
the boiler with it permanently bypassed, just trusting the overheat
cut-out.

I've two options, replace the whole temperature control, which
incorporates the limit stat, or fit an older version stat to the unused
bracket on the output pipe where it used to be fitted, and save money
and time.

Keith


Don't run the boiler continually with the thermostat by-passed, just by-pass
it for the duration of the test. Other components can cause the same
symptoms, so the each have to be eliminated from the loop before the real
fault is found. Testing the 'stats is one of the easiest tests to do
because it's normally done by simply by-passing them to see if the fault
clears itself. Running the boiler for 30 minutes to see if the 'stat is
actually causing the problem won't hurt the system as long it's a supervised
test. Don't do the test by turning it on and walking away from it.