Blog/Lifting pumps: when they're needed in renovation
Contractors

July 13, 2026

5 min read

Lifting pumps: when to install one in renovation in 2026

In renovation, when wastewater drainage can't follow the slope or the discharge point is higher up, you need a reliable solution, not a workaround that comes back to haunt you in after-sales calls. Properly installed, it secures the job, prevents backflow, and saves you precious time on connections. What remains is knowing exactly when it's really needed, and how to size it without overspending.

Contents

Spotting the situations where a lifting pump becomes essential in renovation

Level too low: drainage point above the fixtures (WC, shower, utility room)

When the wastewater outlet is higher than the fixture, gravity flow can't get started. A WC installed lower than the stack, a walk-in shower with no reservation, or a utility room at garden level are typical cases. A lifting pump then pushes the effluent up to the collector, with a suitable check valve and ventilation.

Creating bathrooms in a basement or an extension far from the existing network

In a basement, you're often below the level of the mains sewer. In an extension, distance and level changes sometimes require pumping rather than a deep trench. The pump becomes a clean solution for connecting a new bathroom without disrupting the existing network.

Older network: insufficient slope, reverse slope, long runs and pressure loss

On older systems, surprises come quickly: too shallow a slope, a pipe that rises, a very long run, bends in series, reduced diameters. The result is deposits, blockages and odours. Before digging up the whole floor, a pump can secure the drainage, provided you check the available slope and expected flow rates.

Choosing the right lifting pump for the water being handled

Pump for clear water: shower, basin, washing machine (limits and precautions)

For a shower, basin or washing machine, start with a lifting pump for clear water. It's designed for lightly loaded water. Avoid clumps of hair, fibres and products that form deposits. Plan for a small filter if needed, a check valve and, above all, easy access for cleaning. Also check the permissible temperature if the machine washes at high heat.

Pump for wastewater: kitchen and utility room (grease, temperature, maintenance)

In a kitchen or utility room, the water is "dirtier". Grease and soap quickly foul the tank and impeller. Aim for a pump with a wider free passage, or even a vortex impeller depending on the model. Check the temperature rating. And plan for regular maintenance, with rinsing and degreasing.

Pump for foul water: WC (macerator or dedicated lifting pump, clogging risks)

For toilets, choose a pump designed for foul water or a macerator if the setup requires it. Risk number one remains clogging. Wet wipes, towels and cotton buds must be banned. Add a level alarm, suitable ventilation, and a properly sized discharge line to limit blockages.

Validating feasibility on site before installing the pump

Calculating lifting height and flow rate: the measurement points that change everything

On site, measure the level of the lowest drainage point and the level of the discharge point. The lifting height is mainly about the vertical rise, then the losses from length, bends and constrictions. Also estimate the flow rate to be lifted based on the connected fixtures, to avoid a pump that runs continuously or, conversely, one that starts up too often.

Checking the discharge line: diameter, check valve, ventilation and odour protection

Check the discharge diameter specified in the manual. Install an accessible check valve, then an isolation valve so you can work on it without draining the whole network. On the odour side, a trap or water seal helps, and network ventilation must stay consistent. Protect the pipe from frost, UV and impacts.

Planning ahead for the power supply and safety: circuit breaker, alarm, maintenance access

Identify a dedicated, properly sized power supply. Plan for a dedicated circuit breaker and RCD protection suited to the location. A high-level alarm avoids nasty surprises. Finally, leave enough maintenance access to remove the pump, clean the tank and test the safety devices.

Installing a lifting pump to industry standards in renovation

Placement and installation: tank, anti-vibration mounts, access hatch and noise reduction

In renovation, start by choosing a location that's accessible, ventilated and frost-free. The tank must sit perfectly level, on a rigid base. Plan for suitable anti-vibration mounts and, if possible, a support decoupled from the structure to limit vibration. Keep an access hatch large enough for maintenance, float replacement and cleaning.

Clean connections: sealing, isolation valves, traps and anti-vibration fixings

Take care with sealing the inlets and outlets. Install an isolation valve and a check valve on the discharge line. On the inlet, a trap or water seal prevents odours rising back up. Use flexible couplings and clips with inserts for anti-vibration fixings and a network that doesn't knock against the walls.

Testing and commissioning: load test, leak check, float/sensor adjustment

Run a load test with several cycles. Check for leaks, noise, overheating and breaker tripping. Adjust the float or sensor to avoid overly frequent start-ups, and validate the high-level alarm if fitted. A well-adjusted pump means a job that stays quiet.

Ensuring durability in 2026: maintenance, common faults and good practices

Simple maintenance plan: rinsing, check-valve inspection, tank and float cleaning

To keep your pump reliable, go for light but regular maintenance. Every month, rinse with clear water, check that the check valve isn't sticking, and remove deposits around the float. Twice a year, cut the power supply, open the tank, clean the walls and check the seals for tightness.

Troubleshooting common issues: frequent tripping, noise, loss of prime, blocked discharge

  • Overly frequent tripping. Fouled float or a setting that needs revisiting.
  • Noise or vibration. Foreign objects in the impeller, loose fixings.
  • Loss of prime. Air intake, level too low, leaking check valve.
  • Blocked discharge. Grease deposits, insufficient slope, obstructed bend.

Recommendations for the customer: what should never go down the drain, monitoring and preventive visits

Explain to the customer that the tank isn't a bin. Banned waste in toilets and sinks, even "biodegradable" items. Offer a maintenance logbook, an annual test (alarm, check valve, current draw), and a preventive visit before winter if the installation is in a cold location. To go further on the broader context of the works, also consider checking the key points of drainage and renovation beforehand.

  • Wet wipes, sanitary products, cotton, hair.
  • Grease, oils, coffee grounds, sand, cat litter.
  • Paints, solvents, paint strippers.

Key figures

0.5 to 1 L/h

Boiler condensate

3 to 5 (acidic)

Condensate pH

mandatory in some cases

Neutralisation

Frequently asked questions

Systematically fit a check valve on the discharge line and an isolation valve so you can work on the unit without draining the whole system. The tank must be vented (primary venting or via a membrane vent depending on the setup) to avoid trap seal loss and odours; follow the manufacturer's instructions and the DTU 60.11/60.1 rules on drainage.

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Louis Meneteau

Louis is CPO of Argile. An engineer by training, he spent four years validating calculation software in systems engineering, then three years in software product. He turns the installer's daily reality into product workflows: technical survey, sizing, quotes and subsidy files. His articles describe field gestures rather than principles, because he watches them on site before specifying them.

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