We have a spa with heater protected by a GFI 30 amp Circuit Breaker.

Is there anything inherent in the device to cause them to go bad? I just
replaced it after 6-years.

The original CB also failed after 6-years. Both times, it was after being
tripped off all summer because the heaters were not needed, and then would
not reset.

Other than tripping it off four (4) times a year when servicing the spa,
nothing is done to it.

We don't bother to check it monthly. Would this have any bearing on it's
failure.

The things are far from cheap, so I wonder if there is anything we are ( or
are not) doing which causes them to fail.

Thanks in advance,
Thermo