Lifting Station: How to Add Pump Failure Alerts.

A lifting station collects wastewater from rooms below the backflow level in a tank and pumps it through a pressure pipe into the sewer. Typical uses are basement bathrooms, laundry rooms and granny flats. The DIN EN 12050 series of standards distinguishes three types:

• Part 1: sewage lifting stations for wastewater containing faeces, for example from a toilet
• Part 2: wastewater lifting stations for faeces-free wastewater from showers, washbasins or washing machines
• Part 3: small lifting stations for limited use

The real backflow protection is the backflow loop: the pressure pipe is routed above the backflow level before it joins the sewer. That way water from the sewer cannot push back into the unit even during backflow. The non-return valve in the pressure pipe is not backflow protection. It only stops water in the pipe from flowing back when the pump switches off. More under backflow protection.

Unlike an open pump sump, the tank of a sewage lifting station is sealed and vented through the roof.

If the pump fails, wastewater keeps flowing into the tank, but nothing flows out. The tank’s emergency storage volume fills up quickly. After that, water rises in the connected drainage points: shower, floor drain, toilet. With a sewage lifting station this is not clean water but wastewater full of germs that soaks tiles, screed and walls.

The causes are the same as with any basement pump: power cut, tripped fuse, a blocked pump or faulty level sensing. More under pump failure.

The difference from a simple pump sump: many lifting stations have a control unit that detects and reports a fault. The only question is whether the message reaches you.

Many control units come with three things. A look at the manual or the rating plate tells you which of them your unit has:

• Local alarm: a buzzer and a light on the control unit signal high water in the tank or a fault. On the Zehnder Kompaktboy the buzzer is rated at 85 dB(A). That is enough for the basement corridor, but not for a bedroom two floors up, and certainly not while you are on holiday.
• Volt-free contact: a switching output that changes over when a fault occurs. An external signal device, a GSM module or a building management system can be connected to it. On some units it is standard, on others an accessory. Kessel offers it for its Comfort control units as a plug-in board for retrofitting.
• Battery backup: crucial during a power cut. Kessel’s Comfort control units have battery backup, report a mains failure and check their own batteries. If your control unit has no battery, the alarm goes silent too when the power fails. That is why Zehnder explicitly recommends an additional mains-independent alarm unit for the Kompaktboy, one that also triggers during a power cut.

So whether your alarm works without power depends on the unit. Test it: when nobody is using water, briefly switch off the unit’s circuit breaker and listen for the control unit. Then switch it back on.

Jung Pumpen also points out that the fault alarm should be noticeable in every self-contained dwelling. In an apartment building, a buzzer in the basement is therefore not enough.

1. Remote signalling module from the manufacturer

The obvious solution if one exists for your control unit:

• Kessel: the TeleControl GSM modem (item no. 28792) for the Comfort control units forwards messages to up to three mobile phones. You supply the SIM card yourself. Factory list price €587 plus VAT.
• Jung Pumpen (Pentair): HighLogo controls from December 2020 onwards can be retrofitted with a GSM module that reports faults by SMS or email to up to three recipients. An optional battery module keeps alarm forwarding going even during a mains failure. For BasicLogo and older HighLogo controls there is the separate GSM Pro 2 modem. Installation is a job for qualified personnel.

The downside: tied to the manufacturer, with its own SIM card and installation by a specialist.

2. Volt-free contact plus signalling device

If your control unit has a volt-free fault contact, an electrician can connect a universal GSM alarm unit or the input of a smart home hub to it. Grundfos, for example, lists several volt-free contacts for the LC 221 control of its Multilift units, including high-water alarm and common fault. That is flexible, but the signalling device itself must keep running during a power cut.

3. Mains-independent alarm unit

A separate device with its own backup power supply and an input for a float, such as the Wilo DrainAlarm (list price €587 plus VAT) or the add-on module Zehnder offers for the Kompaktboy. It alarms even during a power cut, but only on site. The message only reaches your phone with an additional remote signalling device.

4. Water leak detector on the floor

A Wi-Fi water leak detector such as the Shelly Flood needs no hub and runs on battery. But it only alerts once wastewater is already on the floor. And during a power cut the router and internet go down, so no push notification gets through. Useful as an add-on, too late as the only protection. See water leak detector.

5. Level sensor with app

A water level sensor measures the level in the pump pit or tank and alerts you when it rises, before anything overflows. Independent of the manufacturer and without touching the control unit.

Drainbee is such a level sensor. Its hydrostatic probe measures the water level in unpressurised tanks and pits up to 1 m to within ± 1 cm, adaptively every 10 seconds to 5 minutes. The wall box sends the data over Wi-Fi (2.4 GHz) to the cloud. You get an alarm when the level passes your threshold, on power outage and on Wi-Fi loss, as a push notification or call-style alarm in the app. You can see the pump cycles in the history. €298 one-off, no subscription.

Two things you should clarify beforehand:

• Access to the water: on units with an open pump pit, the probe simply hangs in the pit. The tank of a sewage lifting station, on the other hand, must stay odour- and gas-tight. Ask your installer to show you where the probe can go in through a sealed cable gland, rather than leaving an inspection cover open.
• Limits: Drainbee does not control a pump and replaces neither the control unit nor maintenance. It has no battery and no cellular module. If the power fails, you get the power outage alarm; after that the box sends nothing until power returns.

Lifting stations must be maintained regularly by a competent person. The intervals under DIN EN 12056-4, as Zehnder for example reproduces them in its manual:

• every 12 months in a single-family home
• every 6 months in an apartment building
• every 3 months in commercial and industrial premises

In addition, Zehnder recommends that you as the operator check it yourself once a month: unusual running noises, leaks, messages on the control unit. If you notice anything unusual, call in a professional.

During maintenance, the specialist checks connections and seals, gate valves and the non-return valve, cleans the tank and level sensing, checks pump, motor and current draw, tests the alarm device and, for a mains-independent alarm, replaces the battery as specified by the manufacturer. The work is documented. Keep the report: according to Jung Pumpen, many insurers ask for proof of the lifting station’s condition after storm damage. A maintenance contract saves you having to remember.

1. Stop more water flowing in. Do not shower or flush in the basement, and stop the washing machine and dishwasher if they drain into the unit.
2. Read the display. Many control units show the cause, such as high water, overcurrent, mains failure or level fault. Note the message.
3. Check the power. The unit’s fuse and RCD. If the fuse keeps tripping, do not keep switching it back on.
4. Manual mode only briefly. Many controls have a button for manual operation. For the Kompaktboy, Zehnder only allows it when the alarm is due to an overfilled tank, and only briefly.
5. Use the manual diaphragm pump, if there is one, to empty the tank above the backflow level in an emergency.
6. Call a specialist or the manufacturer’s service. Do not open the tank of a sewage lifting station yourself. Gases form inside, and the wastewater is a hygiene hazard.