"Rejected_spam" wrote in message
...
In message , John
wrote

I cannot think offhand of a bit of vulnerable threaded bent pipe on an
old
type GlowWorm boiler

Thermocouple?


Threaded pipes are usually connected to the gas valve and other bits
surrounding it. If they're soft malleable iron, then they can corrode. But
Id've thought that they the gas valve and other bits could be easily
replaced if the makers or parts licensors where still in business.