TL;DR
A Saniflo or macerator that hums but will not clear, trips the power or shows no life usually has one of three problems. Either the cutting chamber is blocked, there is an electrical fault, or the motor, blades or seal have worn. A few checks are safe to do yourself. Once you reach the motor, wiring or pump seal, it is an engineer's job. Request a free quote online and describe what you see, because the symptom tells us a lot before we arrive.
Decoding the symptoms
Humming, but nothing flushes. The motor has power and is trying to turn, but the blades are jammed. A wipe, a sanitary item or limescale in the chamber is a common cause. The motor keeps making noise, yet it cannot build the pressure to push waste out.
The unit trips itself or the circuit. A macerator that trips the breaker is drawing too much current. The impeller may have seized, there may be a wiring fault or a failing capacitor may be to blame. Resetting the breaker once is fine. If it trips again at once, leave it off, since forcing it can burn out the motor.
No hum and no sign of life. First rule out the power supply, such as a tripped breaker, a blown fuse or a loose plug. If power is fine and the unit stays silent, the fault has probably moved to the motor windings, the seal or the control board. An engineer should test those properly.
Why many flats rely on one of these units
Many homes in Brighton area are Regency and Victorian terraces converted into flats. In a lot of these buildings, the original soil stack only ran from street level upwards. Turn a lower-ground room in Kemptown area or Hove area into a flat, and there may be no fall left for a normal waste pipe to reach the drain. Lowering floors to create one is rarely practical, especially in a period building.
A Saniflo-type macerator solves this by grinding waste and pumping it up a narrow pipe to the stack. It is clever engineering for a tight retrofit. However, the whole bathroom then depends on one mechanical unit instead of gravity. When it fails, there is no fallback.
What is safe to check yourself
Before anyone opens the unit, a few checks need no contact with live parts or the chamber.
- Check the power. Make sure the unit is plugged in or the spur switch is on, and look for a tripped breaker. Reset it once only.
- Listen. A steady hum means the motor has power, while silence points to the supply. Grinding suggests something solid is catching the blades.
- Look at the inlet for visible tissue or a wipe, without putting a hand inside the chamber.
- Check the small air vent for dust or debris, because a blocked vent can stop the pump discharging.
- Look for water around the base, which can point to a failing seal. Note it, but do not dismantle the pump.
If clearing a visible obstruction fixes it, test the flush again. If the fault stays, or you smell burning or see a leak, stop there.
When it needs an engineer
Some faults are beyond what is sensible to tackle yourself. Pushing on with a jammed or tripping unit often turns a repair into a replacement.
- Jammed blades or a burnt-out motor, where grinding does not stop once visible debris is out
- A failing pump seal, shown by water around the base while the unit is idle
- Electrical faults, such as repeated tripping, a burning smell or scorch marks
- Control board or sensor faults on newer units that behave erratically
- Pipework or vent problems, such as a blocked vent that overloads a healthy unit
Looking after the unit
Most repeat faults trace back to what goes down the toilet. Flush only human waste and toilet paper, not wipes, sanitary items or cotton buds, even if the pack says flushable. Fat and food waste cause the same trouble over time. Keep the vent clear, and have the unit checked before it fails rather than after.
A struggling macerator often shows up alongside slow drains, so read our guide to unblocking a shower or bathroom drain. Our article on basement flat drainage covers the wider picture. For the toilet itself, see how to unblock a toilet. A smell from a lower bathroom may be covered in our guide to bathroom smells.
Frequently Asked Questions
Can I keep using the toilet while the macerator is broken? No. A failed unit can back up into the shower tray or pan, much like flushing a blocked toilet that is already overflowing.
Should I repair or replace a failed unit? It depends on the age of the unit and the fault. A worn membrane or limescale is usually worth repairing, while a burnt-out motor on an old unit may be better replaced. We explain both options before any work starts.
Why does it keep jamming when I am careful what I flush? Limescale in the chamber, a worn cutter or a partly blocked discharge pipe can all cause repeat jams. Have it looked at instead of clearing it yourself again and again.
