"Aidan" wrote in message
oups.com...

Doctor Drivel wrote:

I never misunderstodd at all and I agree with you. I was looking into
what
he had. If the boiler is a sealed compatible boiler (which it "appears"
to
be) then there is no immediate chance of explosion, and as I said get it
sorted ASAP.

You can't have read it then. Re the pressure relief valve, he said;

It's been checked, cleaned and the
washer replaced a couple of times and is
fine. In any case the system is always
vented to the bottom of the loft tank
as I have said.

He has dismantled the safety valve.

...and cleaned it.

The ones I've seen in the past 10 or 15 years were factory pre-set, no
user adjustable parts. It's probably a spring-loaded antique and the
setting has been lost in dismantling.

Some of them you could split and clean, he has done that. That does not
mean it is now unoperatational.

The boiler is probably a similar
vintage. Almost certainly not suitable for sealed system operation and
no manual-reset secondary thermostat.

"every" boiler I have seen with an integral pressure relief valve has been
suitable for a sealed system (why is it there?), that is going back to
boilers made 30 years ago (a few still around). In ye olden dayes, a
presure relief valve was fitted to the flow pipe of open vented boilers.
This would blow off in the kitchen. It was made illegal and required a pipe
to outside. Then they never required one at all on open vented systems.

Now it hasn't got an open vent or a working safety valve either.

I told him to check the suitability of the boiler for sealed systems. I
would be confident the valve would work.