Intermittent Open Sensor Problem

["tx_manx" <tx_manx@xxxxxxxxxxxxx>]

Need your advice. I got the situation accurately constrained (i.e., not
a wide open SNAFU...)

Problem Statement
=================
On Zone 1 only...
Keypad indicates OPEN even though all doors and windows are closed.
Doors (say A and B) fail to chime when repeatedly opened/closed.
Other doors and windows chime, but pad stills says OPEN.
Usually problem exists for a couple days then heals itself.
Then problem returns.

Generally speaking, this problem is relatively recent with years of
reliable prior service.

Experimental Results
====================
I took a strong magnet and tried to trigger sensors A and B.

Opened door A (no chime), put magnet on sensor, but no chime.
Closed door A. (...obviously, no chime, pad still says open)

Open door B (no chime), put magnet on sensor, CHIME!!
Remove magnet, CHIME!
Close and open door A. CHIME! CHIME!
Close and open door B. CHIME! CHIME!
Keypad accurately depicts open/close.

...then (within minutes/hours) keypad stuck on open again.

Magnet trick fixes the problem again (temporarily).

Possible Root Causes
====================
Door B (the front door) does not close tightly.
It moves easily 3/8 inch in-out when "closed".
Damn kids slam door, so it likely vibrates 5 times before settling.
Door jam sensor and door magnet poorly aligned.
They overlap less than 50% when closed.
Vibration would cause the overlap to decrease.

Per past thread, a vibrating door might confuse the controller.

Possible Correct Actions
========================
A] Lock the kids outside.
B] Replace the sensor.
C] Move the door magnet to increase overlap with sensor.
D] Replace old weather stipping to try to reduce door vibration.

Or, some other advice...

Thanks in advance!!

Texas Manx