Toilet in the basement without a sloped sewer line: here's how it works
Quick answer: If the sewer is higher than your toilet, you need a toilet macerator pump. This unit grinds the wastewater and pumps it through a thin pressure pipe (Ø 25–40 mm) upwards to the sewer. If it's just a toilet (and possibly a sink or shower), a compact macerator pump will suffice. A complete bathroom or a high pumping height requires a more powerful installation.
How does a toilet macerator pump work?
A toilet macerator pump is a compact lifting unit installed directly behind or next to the toilet. The toilet flushes into the macerator. As soon as water enters, a pump with a cutting mechanism made of hardened stainless steel starts, finely grinding faeces and toilet paper. Afterwards, it pumps the water upwards and to the sewer through a thin pipe, sometimes many meters away.
Because the water is macerated, the pipe does not need to be thick. This allows it to be easily concealed within a wall, ceiling, or false wall. This makes a toilet possible in places such as:
- a basement or semi-basement;
- a garage, workshop, or garden shed;
- an attic or extension where there's no existing drainage;
- a practice room or canteen in an annex.
Which installation do you need?
| Situation | Solution | Note |
|---|---|---|
| Toilet only, possibly washbasin or shower | Toilet macerator pump (Sanifox, San.iQ cut) | Pumping height up to 6.5 m, pressure pipe Ø 25–40 mm |
| Deep basement or long pipe run | Heavier installation with cutting mechanism (Sanipower) | Up to 16.5 m pumping height |
| Complete bathroom, kitchen, or multiple toilets | Wastewater lifting station (Sanistar C) | DN 80 pressure pipe, ball check valve |
| Apartments, hospitality, businesses | Dual pump installation | Backup pump takes over in case of malfunction |
Wall-mounted toilet? The V-versions (San.iQ cut V, Saniflux V) fit into a pre-wall installation, so the macerator disappears from view.
What to consider during installation?
- Pumping height and distance: Add the height difference to the sewer to the pipe loss over the distance. Check if the installation can handle it. See calculating pumping height.
- Ventilation: The installation must be able to vent. For larger installations, this is done via a pipe to the outside, or with a carbon filter to prevent odors.
- Backflow: A check valve in the pressure pipe prevents water from flowing back. Larger installations already have this.
- Power: Toilet macerator pumps operate on 230V with a plug. Without power, the toilet cannot be used.
What can and cannot go through?
A toilet macerator pump is designed for household wastewater and toilet paper. Wet wipes, sanitary pads, tampons, kitchen paper, and grease do not belong in it: even macerators can get clogged by these, and the blades will wear out. Put up a sign near the toilet if guests or customers also use it.
More about the different installations: choosing the right lifting station.
Recommended installations
TOILET IN BASEMENT OR GARDEN SHED
HOMA Sanifox / San.iQ cut
Compact toilet macerator pump with cutting mechanism, thin pressure pipe, up to 6.5 m.
from €1,090.95
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DEEP BASEMENT / LONG PIPE RUN
HOMA Sanipower
Up to 16.5 m pumping height, with cutting mechanism or vortex pump.
from €3,607.95
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COMPLETE BATHROOM
HOMA Sanistar C102 / C106
Floodable installation with 40 mm passage and ball check valve.
from €3,102.95
View installationFrequently Asked Questions
Can a toilet be installed without a gravity drain to the sewer?
Yes, with a toilet macerator pump. It grinds the wastewater and pumps it through a thin pressure pipe up to the sewer.
How thick does the pressure pipe of a toilet macerator pump need to be?
For toilet macerator pumps with a cutting mechanism, a pressure pipe of Ø 25 to 40 mm is sufficient, depending on the model.
How high can a toilet macerator pump pump?
Compact models like the San.iQ cut can reach up to 6.5 meters. For a deep basement or long pipe run, the HOMA Sanipower can pump up to 16.5 meters.
Can wet wipes go through a toilet macerator pump?
No. Only wastewater and toilet paper. Wipes, sanitary pads, and grease cause blockages, even with a cutting mechanism.
Unsure which pump is suitable?
Send us a sketch: where will the toilet be located, how high and how far is the sewer? We will calculate for free which installation you need.
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