Short answer: a pump service visit covers safe isolation, leaks at the shaft seals, non-return valves, controls and alarms, and a test run with readings. On booster sets it also covers the diaphragm vessel precharge. On submersible and sewage pumps it covers oil, level sensors and the collecting tank. The checklist below draws on Grundfos and Wilo installation and operating instructions and HSE guidance. The manual for the unit in front of you always comes first.
Download the printable checklist (PDF). No sign-up needed.
How to use it
- Use the sections that match the plant: everyone does "Before you start", "Every pump" and "Readings". Then add the booster set, sump pump or lifting station section.
- Each check names the document it comes from. Where the manufacturer's manual for your unit says something different, follow the manual and note it.
- The intervals here are the manufacturers' recommendations. The service contract and the site's own risk assessment set the visit frequency.
Before you start
| Check | What good looks like | Source |
|---|---|---|
| Isolate the power and lock it off | Supply off and secured so it cannot be switched back on, for example a padlock on the mains switch. Some controllers restart the pumps by themselves after a power cut, and some run a test start after a quiet period, so never rely on the pump being stopped | Grundfos Hydro Multi-S manual, s.12; Wilo SiBoost Smart 1 manual, s.7; Grundfos Multilift MSS manual, s.5.2; Electricity at Work Regulations 1989, regs 12 and 13 |
| Isolate and release the water pressure | Valves upstream and downstream of the set closed, the diaphragm vessel shut off and drained, the set drained if needed. On a lifting station, isolating valves closed or the outlet pipe drained before the non-return valve is opened. Vessels hold gas pressure even when the water side is empty: Wilo warns that too much nitrogen can damage or destroy the vessel and injure people | Wilo SiBoost Smart 1 manual, s.7 and s.8; Grundfos Multilift MSS manual, s.9 |
| Personal protective equipment | Safety footwear and cut-resistant gloves as a minimum on booster sets; waterproof gloves, eye and face protection where there is sewage | Wilo SiBoost Smart 1 manual, s.2.8; HSE INDG198 |
| Sewage: flush first | Pump, pit and tank flushed with clean water and the outlet pipe drained before dismantling; parts rinsed after | Grundfos Multilift MSS manual, s.9; Grundfos Unilift AP manual, s.7 |
| Confined space | Do not enter a wet well, pit, chamber or sewer unless it is essential. If it is, assess the risks, plan how to control them (fumes, lack of oxygen, water flooding in) and have emergency arrangements that do not rely on the emergency services. A space that was safe last time is not safe by default today | HSE, Introduction to working in confined spaces; Confined Spaces Regulations 1997, reg 1 |
| Working alone | The risk assessment says whether lone working is allowed and how you keep in touch. Confined space entry and work near exposed live conductors are examples HSE gives where at least one other person may need to be there | HSE, Protecting lone workers, INDG73 |
| Sewage hygiene | Cuts covered with waterproof dressings; hands washed before eating, drinking or smoking; contaminated kit kept apart from food. Weil's disease is spread by rat urine | HSE INDG198 |
| Hearing | Hearing protection from 85 dB(A) | Wilo SiBoost Smart 1 manual, s.2.9 |
Every pump
| Check | What good looks like, or what to do | Source |
|---|---|---|
| Shaft or mechanical seals | No noticeable leak. Wilo says a slight weep can be normal; noticeable leakage means the seal is replaced | Wilo SiBoost Smart 1 manual, s.9.1 |
| Non-return valves | Close tight. A pump that runs backwards when switched off points to a faulty non-return or foot valve | Grundfos Hydro Multi-S manual, s.13 |
| Noise and vibration | Normal. Noise can mean cavitation: check suction pipe, valves and any strainer | Grundfos Hydro Multi-S manual, s.13 |
| Direction of rotation (three-phase) | Correct. If wrong, swap two phases | Grundfos Hydro Multi-S manual, s.13 |
| Motor protection setting | Matches the pump and motor data; trips investigated, not just reset | Wilo SiBoost Smart 1 manual, s.10 |
| Control panel and indicators | Lamps, display and alarms work; faults shown on the controller read and recorded | Wilo SiBoost Smart 1 manual, s.10 |
| Test run | Starts and stops cleanly in automatic | Grundfos Multilift MSS manual, s.8 and s.9 |
Booster sets
| Check | What good looks like, or what to do | Source |
|---|---|---|
| Ready for operation | Each pump available, in automatic, no standing faults | Wilo SiBoost Smart 1 manual, s.9.1 |
| Diaphragm vessel precharge | Measured on the gas valve with the water side isolated and drained. Set to the figure in the set's manual (examples in the table below). Top up with nitrogen only: Grundfos recommends it, and Wilo refers topping up to its customer service | Grundfos Hydro Solo-S manual, s.5.1; Wilo SiBoost Smart 1 manual, s.9.2 |
| Diaphragm vessel condition | No water from the gas valve. Water there means a leaking diaphragm | Grundfos Hydro Solo-S manual, s.6 |
| Pressure switch or set point | Cut-in and cut-out as designed; cut-out never above the maximum operating pressure of the pump or the vessel | Grundfos Hydro Multi-S manual, s.11 and s.12.2 |
| Starts and stops | No short cycling. If it does, check the pressure setting, the vessel precharge, the diaphragm and the non-return valves | Grundfos Hydro Multi-S manual, s.13; Grundfos Hydro Solo-S manual, s.6 |
| Inlet and dry-running protection | Break tank level and inlet valve working; low-water switch or inlet pressure sensor works | Wilo SiBoost Smart 1 manual, s.10; Grundfos Hydro Multi-S manual, s.13 |
| Frequency converter fan filters | Clean them if very dirty | Wilo SiBoost Smart 1 manual, s.9.2 |
| Break tank (water hygiene) | Inspected and any remedial work done, yearly. Stored water temperature, taken away from the ball valve, compared with the incoming mains, yearly in summer or as the temperature profiling says. If a water hygiene contractor does this, note who and when | HSE HSG274 Part 2, Table 2.1 |
| Expansion vessels (water hygiene) | Flushed through and purged to drain where practical, at the frequency in the site's Legionella risk assessment; bladders changed as the manufacturer or the risk assessment says | HSE HSG274 Part 2, Table 2.1 |
| Frost | A set not used in frosty periods is drained: manifolds, pumps and vessel | Grundfos Hydro Multi-S manual, s.12.3 |
| Manual | Precharge | How often to check |
|---|---|---|
| Grundfos Hydro Solo-S (single-pump set) | 0.9 × cut-in pressure, measured with the system unpressurised | At least once a year |
| Grundfos Hydro Multi-S | About 90% of cut-in pressure, checked with the discharge pipe empty | At least once a year, with the pressure switch settings |
| Wilo SiBoost Smart 1 (single-pump set) | Pump switch-on pressure minus 0.2 to 0.5 bar, or the value in the table on the vessel | A 3-month cycle is recommended |
The full method, with a worked example, is in booster set servicing.
Submersible sump and drainage pumps
These checks come from a drainage pump manual. Grundfos says the Unilift AP is not suitable for sewage; a sewage pump has its own manual and intervals.
| Check | What good looks like, or what to do | Source |
|---|---|---|
| Pump and oil | Pump checked and oil replaced once a year; more often with abrasive liquids or continuous running | Grundfos Unilift AP manual, s.7.1 |
| Oil condition | Clean. Water or dirt in the drained oil means the shaft seal should be replaced | Grundfos Unilift AP manual, s.7.1 |
| Float switch | Free to move; starts and stops at the right levels, with the stop level above the pump inlet so the pump does not draw in air. If the float switch keeps the pump from starting, adjust or replace it | Grundfos Unilift AP manual, s.3.2.5 and s.8.1 |
| Impeller and outlet | Free of debris. A pump that runs constantly or gives little water may be partly blocked | Grundfos Unilift AP manual, s.8.3 |
| Cable | Undamaged. A damaged power cable or level switch is replaced by a workshop the manufacturer authorises | Grundfos Unilift AP manual, s.7 |
Sewage lifting stations
| Check | What good looks like, or what to do | Source |
|---|---|---|
| Inlet, outlet and vent connections | Tight, no leaks; the weight of pipes and valves supported, not resting on the tank | Grundfos Multilift MSS manual, s.9 |
| Power consumption | Within the nameplate figure | Grundfos Multilift MSS manual, s.9 |
| Cable entries | Watertight; cables not sharply bent or pinched | Grundfos Multilift MSS manual, s.9 |
| Pump vent hole | Clear (pump removed from its support flange to check: undo the clamps, do not loosen the flange from the tank) | Grundfos Multilift MSS manual, s.9 |
| Non-return valve | Where it needs cleaning: isolating valves closed or outlet pipe drained first, cleaned through the inspection cover, new cover gasket fitted | Grundfos Multilift MSS manual, s.9 |
| Level sensor | Pressure tube free of deposits; sensor proved with a test run | Grundfos Multilift MSS manual, s.9.2 |
| Controller | Cabinet gaskets sound, cable connections tight, functions and high-level alarm work, backup battery replaced at the annual service if fitted | Grundfos Multilift MSS manual, s.5.2 and s.9.1 |
| Collecting tank and overflow channel | Clean | Wilo EMUport CORE instructions, maintenance and repair |
| Solids separation tanks and screens (where fitted) | Cleaned yearly | Wilo EMUport CORE instructions, maintenance and repair |
Service intervals and the full pumping station routine are in sump and sewage pumping station maintenance.
Readings to record
- Pump make, model and serial number
- Running hours
- Inlet and outlet pressure (bar)
- Cut-in and cut-out pressure (bar)
- Vessel precharge as found and as left (bar)
- Motor current on each phase (A), against the nameplate
- Oil condition (submersible pumps)
- Alarms tested and the result
Who does what
- The dutyholder (the employer or whoever is in control of the premises) agrees the service frequency with you and owns the site's risk assessments, including Legionella.
- The service engineer carries out the checks, records the readings and reports what needs doing.
- The manufacturer or an authorised workshop does some repairs. Grundfos says shaft seal and oil work on the Multilift MSS "must be carried out by the manufacturer or an authorised service workshop".
What to record
For each visit: date, engineer, each check with pass, fail or not applicable, the readings above, parts used, and what was found that needs doing, with how urgent it is. Wilo's lifting station instructions ask for all maintenance and repair work to be written in a log signed by the qualified person and the operator. Keep a photo of any fault.
This checklist in Field Suite
The form library in Field Suite has a ready-made pump service checklist. It records make and model, running hours, inlet and outlet pressure, motor current, and pass/fail checks for noise and vibration, seals, float switches and level controls, the high-level alarm, the control panel and the non-return valves. You can add your own questions, such as vessel precharge, with the form builder. The engineer fills it in on the phone, and it saves as they go, even without signal. A failed check marks the form failed and alerts the office. The signed PDF goes with the job sheet.
- Equipment register: each pump with its service interval and job history, and a QR label to stick on the unit that opens its page.
- Contracts: visits every set number of months, each with the checklist attached, booked ahead of time.
- Van stock and faults: parts come off the engineer's van stock, and faults found on the visit become a quote.
See pump maintenance software, prices, or book a demo.
Field Suite is job management software. The manufacturer's instructions and the site's own risk assessments decide how a pump is serviced.
Sources
- Grundfos, Hydro Multi-S installation and operating instructions, ss.11 to 13. https://api.grundfos.com/literature/Grundfosliterature-3566070.pdf
- Grundfos, Hydro Solo-S installation and operating instructions, ss.5.1 and 6. https://api.grundfos.com/literature/Grundfosliterature-3614.pdf
- Grundfos, Unilift AP12, AP35, AP50 installation and operating instructions, ss.3, 6.2, 7 and 8. https://api.grundfos.com/literature/Grundfosliterature-3279044.pdf
- Grundfos, Multilift MSS installation and operating instructions, ss.5.2, 8 and 9. https://api.grundfos.com/literature/Grundfosliterature-5247333.pdf
- Wilo, SiBoost 2.0 Smart 1 / SiBoost Smart 1 installation and operating instructions, 2535459, Ed.05/2025-03, ss.2.8, 2.9, 7, 8, 9 and 10. https://cms.media.wilo.com/dcidocpfinder/wilo735475/9988007/wilo735475.pdf
- Wilo, EMUport CORE installation and operating instructions, maintenance and repair. https://cms.media.wilo.com/dcianimpfinder/wilo747227/10345479/en-GB/21065007472106519435.html
- HSE, Legionnaires' disease: Technical guidance, HSG274 Part 2, Table 2.1 (expansion vessels). https://www.hse.gov.uk/pubns/priced/hsg274part2.pdf
- HSE, Working with sewage: the health hazards, INDG198. https://www.hse.gov.uk/pubns/indg198.pdf
- HSE, Protecting lone workers: How to control the risks of working alone, INDG73(rev4). https://www.hse.gov.uk/pubns/indg73.pdf
- HSE, Introduction to working in confined spaces. https://www.hse.gov.uk/confinedspace/introduction.htm
- Confined Spaces Regulations 1997, regulation 1. https://www.legislation.gov.uk/uksi/1997/1713/regulation/1
- Electricity at Work Regulations 1989, regulations 12 and 13. https://www.legislation.gov.uk/uksi/1989/635/regulation/12 and https://www.legislation.gov.uk/uksi/1989/635/regulation/13
Last checked: 5 November 2026 against the sources above.
Field Suite is job management software for UK building services firms, not a consultancy. Your own risk assessments, contracts and advisers decide what applies to your work. Spotted a mistake? Email info@fieldsuiteapp.com and we correct it.