[kwlug-disc] winter and furnace

[Mikalai Birukou]

There are these little pipes that go between enclosed area in furnace 
and membrane switches to detect presence of pressure difference between 
normal/room and that enclosed area with air/fumes flow.

Other season, there was a burned ash in one of pipes, after burner, I 
suppose.

One more season, I gently blew in and out of pipe into membrane switch 
to hear it flip. It got unstuck, and continued proper operation.

This season, a pipe had a drop of water in it. Surface tension in a 
small radius obvious stopped pressure difference from pushing membrane.

I guess, cleanup includes dusting furnace, and blowing through some 
pipes. :) Noting that three events happened over 15 years.