T&T: Aqualarm High Water Alarm--(old model)

[Bob/Myrna Siegel]

Aqualarm high water alarm  (15 yrs. old) clicked but did not ring when bilge
switch tested.  Took off faceplate and see a spring loaded plunger which looks
like it is activated by a solenoid.  Rotated plunger and depressed  it several
times. Now unit works fine.
Question..Is this plunger supposed to receive any lubrication?  Reluctant to
lubricate it if it would attract dust. There was no evidence of any lube on it
and it has worked flawlessly for 15 years so??  Bob Siegel Annapolis