How to Install a Macerating Toilet: Step-by-Step DIY Guide 2026

Looking to add a bathroom in a basement, closet, or under-stairs space? A macerating toilet (also known as an upflush toilet) is your solution. This special toilet features a built-in macerator that grinds waste and paper into a fine slurry, then pumps it up to 30 feet horizontally or 10 feet vertically to reach a remote waste stack. No need for a bulky traditional toilet tank – the pump and grinding unit are integrated into the bowl.

In this guide, we'll walk through installing a SaniCompact 43 or similar macerating toilet. Whether you're finishing a basement or converting a storage room, this project can be tackled with basic plumbing and home improvement skills.

What You'll Need Before Starting

• Macerating toilet unit (e.g., SaniCompact 43)
• 32mm discharge pipe (for waste)
• Water supply line (½" flexible hose)
• 230V electrical outlet (GFCI protected)
• Floor mounting bolts and brackets
• PVC primer and cement
• Adjustable wrench and screwdrivers
• Spirit level

Step 1: Prepare the Plumbing Connections

Before setting the toilet, you need to run the necessary lines to the installation spot. The macerating toilet requires three connections: a water supply, a 32mm discharge pipe, and a power outlet. The discharge pipe can run horizontally up to 30 meters or vertically up to 3 meters – ideal for spaces far from the main stack. For the water supply, use a standard ½" shut-off valve. If you're also connecting a sink to the unit (the SaniCompact 43 has an extra inlet), plan for that drain line too. Check out our bathroom vanities collection if you're adding a small sink to complete the space.

Step 2: Mount the Toilet to the Floor

Position the toilet where you want it, ensuring the discharge outlet aligns with your planned pipe route. Mark the floor through the mounting holes, then drill and install the supplied anchors and bolts. Place the toilet over the bolts and tighten it down evenly. Use a spirit level to make sure the bowl is perfectly level – this ensures proper flushing and pump operation. The unit comes with a floor-fixing kit, so no special tools are needed. For the surrounding area, consider adding a rug or wall decor to make the new bathroom feel finished.

Step 3: Connect the Water Supply and Discharge Pipe

Attach the water supply line from the shut-off valve to the toilet's inlet. Hand-tighten, then give it a quarter turn with a wrench. For the waste line, connect the 32mm pipe to the toilet's discharge outlet using PVC primer and cement. Run the pipe to your existing waste stack or to an outside drain. Remember: the pipe can go uphill, but avoid sharp bends – use long-radius elbows to prevent clogs. Secure all pipe runs with the supplied clamps. If you're working in a tight space, our home improvement tools and fittings will help.

Step 4: Electrical Connection

The macerating toilet requires a standard 230V outlet, preferably GFCI-protected for bathroom safety. Plug the unit's power cord into the outlet. The pump and macerator are activated automatically when you flush – no separate switch needed. If you don't have an outlet nearby, hire a licensed electrician to install one. For the rest of the room's lighting, browse our lighting collection for fixtures that meet code.

Step 5: Install the Seat and Cover

Slide the toilet seat onto the mounting posts and tighten the nuts underneath. Attach the lid. Your macerating toilet is now ready to use. Test it by flushing with the light gray button (short flush) and dark gray button (long flush). The pump will run for a few seconds after each flush to clear the line. If you're also connecting a sink, the pump will activate automatically when water enters the auxiliary inlet.

Frequently Asked Questions

Can I install a macerating toilet in a basement?

Yes – this is the most common application. The pump can push waste vertically up to 3 meters, making it perfect for below-grade bathrooms where gravity drainage isn't possible. Pair it with a bathroom vanity and mirror for a complete basement bathroom.

How far can the waste pipe run?

Up to 30 meters horizontally or 3 meters vertically. For longer runs, you may need a larger pipe diameter or an additional pump – consult the manufacturer's specs.

Can I connect a sink to the macerating toilet?

Yes, the SaniCompact 43 has an additional inlet for a lavatory or sink. The pump activates automatically when water enters from the sink drain. This is a great way to add a small vanity to your new bathroom.

Is the macerator loud?

It makes a grinding sound similar to a garbage disposal, lasting about 10–15 seconds per flush. Modern units are well-insulated, so noise is minimal. Adding wall decor or curtains can help absorb sound.

What maintenance is required?

Periodically clean the macerator blades by flushing with a toilet-safe cleaner. Avoid flushing anything other than human waste and toilet paper – no wipes, feminine products, or heavy objects. For long-term reliability, consider a home improvement maintenance kit.

Final Tips for a Successful Installation

• Always use a GFCI outlet for safety in damp locations.
• Support the discharge pipe every 1–2 meters with pipe clamps to prevent sagging.
• Test all connections before closing up walls or floors.
• Keep the instruction manual handy for troubleshooting codes.

With a macerating toilet, you can transform any unused corner into a fully functional bathroom. It's a smart solution for adding value to your home without major construction. Once the plumbing is done, finish the room with rugs, lighting, and wall decor from GrandGoldman to make it feel like a real bathroom.

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