How to install a macerator: step-by-step Saniflo installation
Want a toilet in your loft, basement or garden office? Often there's no drain nearby. Laying a new one means breaking open floors, which is costly and messy. A macerator solves this. It grinds wastewater and pumps it through a narrow pipe to your soil pipe. That works for a pool house toilet too. With basic DIY skills, you can fit one yourself.
Quick summary
You can install a Saniflo macerator yourself with a screwdriver. Fit the couplings on the inlets first. Then connect the outlet at the top or the side. Run the discharge pipe upwards first, then horizontally with a 1% fall. Use bends of 45° at most. Leave the electrical connection to a qualified electrician.
Watch the macerator installation video
Our video shows every installation step. We use the DAB Genix macerator as an example. You can follow most steps for other brands too, such as a Saniflo macerator. Pause the video after each step, so you can work along at your own pace. Haven't bought one yet? First make sure your space meets the requirements for a Saniflo macerator.
Macerator installation step by step
Prefer to read? Follow the steps below. You only need a screwdriver and the parts in the box.
Fit the coupling pieces onto the inlets.
Fit the piece with the flexible flap onto the outlet. The outlet can point up or to the side.
Mounting on the floor? Use the two extendable feet.
Leave the electrical connection to a qualified electrician. The macerator needs a permanent power supply.
Connecting the outlet at the top
Fold the flexible flap of the coupling piece upwards. Now you can reach the bottom part easily.
Put a hose clamp around this part, but don't tighten it yet.
Push the connection firmly over the non-return valve: the tube with the green/black lid. This valve stops wastewater from flowing back into the pump.
Tighten the hose clamp with a Phillips screwdriver, flathead screwdriver or socket driver.
Fold the flap back down over the hose clamp.
Slide a second hose clamp over the end of the coupling piece. Connect your pipe and tighten the clamp.
Pipe doesn't fit? Fit one of the supplied reducers into the pump outlet.
Connecting the outlet at the side
Remove the cover from the pump outlet.
Turn the pump outlet to the side of the pump.
Place the small white cap on top of the cover.
Push in the part with the cutting edge to open the side of the cover. Wiggle it a few times, then pull it off carefully.
Connect the pipe in the same way as for the top outlet.
How to install Saniflo waste pipes correctly
Good macerator pipework prevents blockages and keeps your pump running smoothly. Follow these rules for every macerator waste pipe:
Place the macerator no more than 20 cm behind the toilet.
Run the discharge pipe upwards first, then horizontally. It never works the other way round.
Fit an air vent at the highest point of the pipe.
Give the horizontal pipe a fall of at least 1% (1 cm per metre).
Use inlet pipes of at least 36 mm from your appliances. Narrower pipes can block, because the waste isn't ground yet.
Avoid sharp 90° bends. Use bends of 45° at most.
Fit a straight piece of PVC pipe of at least 10 cm after every bend.
How far can a macerator pump wastewater?
The distance depends on two things: how high the water must go and the pipe diameter. The higher the lift and the narrower the pipe, the shorter the horizontal distance.
For example, with 1 metre of lift and a Ø36.2 mm pipe, water travels up to 90 metres horizontally. With 3 metres of lift and a Ø28.4 mm pipe, that drops by about 30 metres. The diagram below shows the distances for different pipe diameters.
Always check your model's manual for its exact limits.
Ready to fit your macerator?
The right pipe layout lets you add a toilet almost anywhere in your home. Take your time with each connection. Check every clamp before the first flush. Still choosing a model? Our Saniflo macerators and macerator toilets show the inlets and lift height for each one. Not sure which one fits? Our customer service team is here to give you professional advice.
Frequently asked questions about Saniflo installation (FAQs)
Quick answers to the questions people ask most about fitting a macerator.