How to Test a Flow Switch

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A flow switch is used to monitor the flow of different types of substances—usually air or water. It senses different pressure generated from different flows. The flow switch is hooked through a venture to an electronic circuit at a flow level previously determined. In this way, the flow switch acts as a protector to the equipment or appliance. A flow switch is used in damper regulators, water pumps and air conditioning systems. In general, a flow switch is tested annually.


The Right Flow at the Right Time

Step 1

Put cover on the flow switch and turn power on.

Step 2

Start flow through the designated system.

Step 3

Observe flow in operation to determine if flow switch is working properly.

Step 4

Repeat this process many times to ensure flow switch and designated system is in fact working accurately.


If the flow switch is not working properly, adjustments might need to be made. The flow switch should be replaced every five years or 100,000 cycles, whichever comes first.