How to Replace a Saniflo Microswitch and Membrane (DIY Guide)

Why You Should Replace Both Together

When your Saniflo's membrane fails, waste water leaks through and contaminates the microswitch. When the microswitch fails, it often means the membrane has been degraded for some time. For this reason, we always recommend replacing both parts at the same time, along with the horseshoe clip.

Total parts cost: approximately $100–$120 CAD for all three parts.

Before You Start

Identify Your Model and Generation

This is critical — parts are NOT interchangeable between generations. Read our Saniflo model identification guide to determine exactly which parts you need.

Tools Required

• Phillips screwdriver
• Flat-head screwdriver (may be needed for some models)
• Rubber gloves
• Old towels or rags
• A bucket
• Your replacement microswitch, membrane, and horseshoe clip (specific to your model/generation)

Safety

• Unplug the unit from the electrical outlet before starting
• Turn off the water supply to the toilet
• Flush the toilet to empty as much water as possible from the bowl and macerator

Step-by-Step Instructions

Step 1: Remove the Macerator Cover

Remove the screws holding the macerator cover in place (typically 4-6 Phillips screws). Lift the cover carefully. There may be residual water inside — have towels ready.

Step 2: Locate the Microswitch and Membrane

The microswitch is a small plastic component with electrical wires connected to it. The membrane is a round rubber disc located between the wastewater chamber and the microswitch.

The exact location varies by model:

• On most Saniplus models, they're on the upper section of the unit
• The membrane sits in a housing held in place by a horseshoe-shaped clip

Step 3: Remove the Old Horseshoe Clip

Carefully pry out the horseshoe clip. Note its orientation before removing it. On older units, this clip may be brittle and break during removal — this is normal and expected, which is why we recommend always having a replacement.

Step 4: Remove the Old Membrane

Lift out the old membrane. Inspect it:

• Is it cracked or torn?
• Is it stiff rather than flexible?
• Is there waste residue on the microswitch side?

Any of these confirm the membrane was the root cause of the problem.

Step 5: Disconnect and Remove the Old Microswitch

The microswitch typically has two wire connections. Note which wire goes where (take a photo with your phone before disconnecting). Disconnect the wires and remove the microswitch.

Step 6: Clean the Housing

Before installing new parts, clean the membrane housing area thoroughly. Remove any waste residue, limescale, or debris. Use warm water and mild soap — never chemical cleaners.

Step 7: Install the New Microswitch

Connect the wires to the new microswitch in the same configuration as the old one (refer to your photo). Seat the microswitch in its position.

Step 8: Install the New Membrane

Place the new membrane in the housing, ensuring it's oriented correctly (the flat side typically faces the wastewater, and the side with the activator pin faces the microswitch). Make sure it seats fully and evenly.

Step 9: Install the New Horseshoe Clip

Press the new horseshoe clip into place. It should click in firmly and hold the membrane securely. Verify the membrane doesn't move or shift after the clip is installed.

Step 10: Reassemble and Test

1. Replace the macerator cover and secure all screws
2. Plug the unit back in
3. Turn on the water supply
4. Flush the toilet and verify:

- The macerator activates when flushed - The macerator stops after the flush cycle completes (10-15 seconds) - No water leaks from the unit - The "won't stop running" problem is resolved

Troubleshooting After Replacement

Motor doesn't activate after replacing parts:

• Verify wire connections to the microswitch
• Check that the membrane is properly seated and the horseshoe clip is secure
• Ensure the unit is plugged in and the outlet is live

Motor still runs continuously:

• Verify you ordered the correct parts for your specific generation
• Check that the membrane orientation is correct
• Ensure the horseshoe clip is fully seated

Water leaking from the unit:

• The cover gasket may need repositioning
• Check that all screws are evenly tightened

Order the Right Parts

We carry microswitch and membrane kits for every Saniflo generation. Use our parts breakdown pages to find the exact parts for your unit.

Shop Saniflo Microswitches → | Shop Saniflo Membranes → | Shop Horseshoe Clips → | All Parts Breakdowns →