How to Make a Float Switch

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Things You'll Need

  • Snap action switch

  • Schedule 40 PVC pipe, 1/2-inch

  • Pipe cutters

  • Power driver

  • 7/32-inch drill bit

  • Utility knife

  • PVC adhesive

  • 3/16-inch drill bit

  • PVC tee

  • 3/8-inch drill bit

  • 12 oz. soda bottle

  • Schedule 40 PVC pipe, 3/4-inch

  • Phillips screwdriver

  • Wood screws, 3/4-inch

  • Switch arm

  • Mounting screw, 2-inch

A float switch regulates the water level and turns off the main pump when reaching a certain point of overflow. Likewise, it also moderates low water levels by ensuring the reservoir never runs dry. Building your own float switch requires a simple setup consisting of several drill holes, mounting screws and cheap, reliable parts. Most of the materials rarely exceed the ten-dollar margin. Benefits of this float switch model include a lack of submersible electrical wires, reliable switch operation, critter-free deterrents, no relays, no 12-vault adapters, no reed magnets and no moving parts in the water. It allows for a 5-inch water level after installation.


Step 1

Cut off 5 inches from the 1/2-inch schedule 40 PVC pipe with pipe cutters. Drill 4 adjacent 7/32-inch holes in the middle of the PVC pipe thereby creating a suitable float switch housing.

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Step 2

Use a utility knife to cut out the float switch slot in accordance with its dimensions, preferably 1/2-inch from the end of the PVC pipe. Try to create a snug float switch slot to avoid using unnecessary adhesives. Push the float switch through the slot and into the housing. Use a PVC adhesive to seal the float switch into place if necessary.


Step 3

Drill two adjacent 3/16-inch holes on the pipe's opposite ends. Create holes round and long enough to allow the screw and hinge to slide in and out easily on an angle. Drill two adjacent holes on the PVC Tee's opposite ends. Drill two adjacent 3/8-inch holes on the PVC outlet side to allow mounting accessibility.

Step 4

Apply pressure and insert the 1/2-inch PVC pipe into the 12 oz. soda bottle. Insert the 3/4-inch pipe into the PVC tee. Insert the other end of the 1/2-inch PVC pipe into the 3/4-inch thin-walled pipe, which will work as a sleeve to help the 1/2-inch pipe slide up and down easily.


Step 5

Position the PVC tee directly over the water near the float switch's main location. Use a Phillips screwdriver to mount the PVC tee to the cabinet's roof with 3/4-inch wood screws. Join the switch arm to the PVC tee until reaching the center. Use a 2-inch mounting screw to secure the switch arm to the cabinet's roof. Do not over-torque or screw completely. Allow 3/8-inch space between the cabinet roof and the switch arm pipe for maneuverability.