low water alarm intermittently going off

[Cuppa]

Have you tried pulling the sensor out and cleaning it or maybe the sensor is faulty.???.

The ’sensor’ is only a machine screw screwed into a plastic sleeve.

Whilst in contact with the coolant it maintains an electrical circuit. If the electrical circuit is broken the alarm goes off. So whilst a dirty ’sensor’ could cause the problem, it would be very unlikely for it to be intermittent. It would also seem not possible for it to be faulty. I would think that a faulty connection/internal break in a wire might be the most likely cause, but the fact that revving the motor stops the alarm sounding points more to the ’sensor’ losing contact with the coolant.