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
Note NO....SPAM measures, the fix should be obvious