Cicero wrote:
On Tue, 11 Nov 2008 00:00:22 +0000, geoff wrote:
Cicero writes

Blow through the air switch tubes - might be a bit clogged up with dust.
It might not work but at least it can't do any harm.

Well yes it can

you can rupture the APS diaphragm

I meant *disconnected* tubes and should have said so because I wouldn't
ever suggest blowing dust *into* any piece of equipment like a switch.

It's a fair point - without the warning I quite likely would have blown
through the valve body. I'd hope that I have sufficient mechanical
sympathy not to rupture anything in the process though, unless these
diaphragms are unusually sensitive.

At the moment, I'm hoping it's just the wind direction as BigWallop and
Geoff suggested :-). It hasn't happened again since I posted.

Pete