How to Install an Upflush Toilet in Your Basement (Complete Guide)

Why an Upflush Toilet for Your Basement?

Adding a bathroom to your basement traditionally means one thing: jackhammering through the concrete floor to reach the sewer line below. That's messy, expensive ($6,000–$15,000+), and can take weeks.

A macerating upflush toilet eliminates all of that. It sits on top of your existing floor and pumps waste UP to your existing sewer line — no digging, no concrete breaking, and typically installed in a single day.

How Macerating Toilets Work

A macerating toilet system has three main components:

1. The toilet bowl — A standard-looking toilet that sits on the floor
2. The macerator unit — A box that sits behind the toilet containing a motor, macerating blade, and pump
3. The discharge pipe — A small-diameter pipe (typically 3/4" to 1") that carries the macerated waste up to your existing sewer line

When you flush, waste enters the macerator unit. The blade grinds everything into a fine slurry, and the pump pushes it through the discharge pipe up to the sewer connection. The system can pump vertically up to 15 feet and horizontally up to 150 feet (varies by model).

Before You Start: Planning Checklist

What You Need

• [ ] Water supply line — Cold water connection for the toilet
• [ ] Electrical outlet — A dedicated 120V outlet within reach of the macerator (ideally on a GFCI circuit)
• [ ] Sewer connection point — Access to your home's main drain or soil stack
• [ ] Vent connection — Connection to your home's vent stack (or an AAV — Air Admittance Valve where code permits)
• [ ] The macerating toilet system — Toilet bowl + macerator unit + discharge pipe fittings

Permits and Codes

Most Canadian and US municipalities require a plumbing permit for a new bathroom. Check with your local building department. Key considerations:

• Electrical work may require a separate permit
• Some jurisdictions have specific requirements for macerating systems
• Venting requirements vary — some accept AAVs (Air Admittance Valves), others require traditional venting

Cost Comparison: Upflush vs Traditional

Step-by-Step Installation Overview

Step 1: Choose Your Location

• The macerator can pump waste up to 15 feet vertically, so your basement bathroom doesn't need to be directly below an existing bathroom
• You DO need access to a sewer connection point within the pump's horizontal range (up to 150 feet for most models)
• Plan for the discharge pipe route — it needs to reach the sewer connection

Step 2: Run the Water Supply

• Connect a cold water line to the toilet location
• Standard 1/2" copper or PEX is fine
• Install a shut-off valve at the toilet connection point

Step 3: Install the Electrical

• A dedicated 120V, 15-amp outlet is required near the macerator unit
• GFCI protection is recommended (and may be code-required in a bathroom)
• The macerator should NOT be on a switched circuit — it needs constant power

Step 4: Install the Discharge Pipe

• Run the small-diameter discharge pipe from the macerator location to your sewer connection
• Use rigid PVC or the pipe type specified by the manufacturer
• Include a non-return (check) valve to prevent backflow
• Connect to the existing soil stack or drain above the flood level of the fixtures

Step 5: Install the Vent

• Connect to an existing vent stack, OR
• Install an AAV (Air Admittance Valve) where permitted by local code
• Proper venting prevents gurgling and slow drainage

Step 6: Position and Connect the Macerator

• Place the macerator unit where the toilet will sit
• Connect the discharge pipe output
• Connect the vent
• Do NOT permanently seal or screw down the macerator at this stage — you may need to access it

Step 7: Install the Toilet Bowl

• Mount the toilet bowl onto the macerator unit's inlet
• Use the provided gaskets and fittings
• Connect the water supply to the toilet fill valve

Step 8: Test

• Plug in the macerator
• Turn on the water supply
• Flush the toilet and verify proper operation
• Check all connections for leaks
• Verify the non-return valve is working

Adding More Than Just a Toilet

Most macerating systems can handle additional fixtures. The Saniflo Saniplus, for example, has inlets for:

• Toilet (rear inlet)
• Sink (side inlet)
• Shower (side inlet, low-level)

This means you can create a full three-piece basement bathroom with a single macerating unit.

Common Installation Mistakes to Avoid

1. No check valve — Always install a non-return valve. Without it, waste can flow back into the unit.
2. Undersized discharge pipe — Use the pipe diameter specified by the manufacturer.
3. Wrong vent setup — Improper venting causes gurgling, slow drainage, and odour problems.
4. Switched electrical circuit — The macerator needs constant power. Don't put it on a light switch circuit.
5. Using silicone on discharge connections — Use the manufacturer's recommended sealant or compression fittings.

Need Help Choosing a System?

Our team has helped thousands of Canadian homeowners add basement bathrooms with macerating toilet systems. We carry the full Saniflo range and can help you choose the right system for your space.

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