When someone rings us about a water pump, they are usually calling because something has already gone wrong: a basement filling up with water, a pump that has failed, or the realisation that an emergency plan relies on a cheap DIY store pump that could not empty a sink, never mind a cellar.
Before we recommend anything, we run through a structured set of questions. Not because we love forms, but because getting the wrong pump is one of the most common and most expensive mistakes people make.
These are the exact questions we ask on every call, and the reason behind each one.
1. What is the water pump actually for?
Most problems start here.
There is a huge difference between pumping:
- Groundwater seeping through a floor
- Water from a well for irrigation
- Rainfall collecting behind a flood barrier
- Silty water from a construction site
- Sewage
- Clean water transfer
Each situation needs a completely different pump. Using the wrong type normally ends with burnt-out motors, constant blockages, or a pump that simply cannot move the water.
Getting this right is the foundation for everything else.
2. How high does the pump need to lift the water?
This is called the head height, measured in metres.
If the pump cannot overcome the vertical lift, for example from a basement up to ground level, it will not pump anything, even if it appears to run.
This one detail rules out more unsuitable pumps than anything else.
3. How far does the water need to travel?
Distance matters. People often say, "I need to pump the water to the end of the garden." We will always ask, "How far is that exactly?" We are not being difficult: the distance genuinely matters, and it helps us specify the right pump so it works when you need it.
Long discharge lines create friction losses, which dramatically reduce how much water the pump can move. It will also determine what size of discharge hose is likely to be needed.
We would want to understand:
- Total length of hose or pipe
- Number of bends
- Pipe diameter
A pump that performs well on paper can slow to a trickle if the discharge pipework is not matched to it, and as a result burn out.
4. What voltage do you have available?
Most homes have 230V, while construction sites often need 110V.
Choosing the wrong voltage means:
- The pump cannot be plugged in
- Safety risks if the wrong voltage is specified
This is a simple question that ensures suitable usage.
5. Do you need the water pump to turn off and on automatically?
If a pump is part of a flood strategy, it may need to start on its own.
Float switches make this possible, but not every pump has them, and some versions do while others do not.
Manual pumps are fine for emergency response if someone is physically present. Automatic pumps are essential for sump pits, basements and overnight events.
Automatic pumps are not likely to pump as low, leaving nuisance water behind, so it is important to consider what is more valuable.
6. What pipework or hose are you using?
Performance depends as much on the discharge pipe as the pump itself.
Too small, and pressure builds while the flow rate collapses. Too large, and the water slows and sediment settles.
We will likely check what hose you have, to make sure the whole setup works. We can specify or supply the hose to match the pump, and we also have handy videos explaining when you might want layflat hose or suction delivery. Layflat is cheap, easy to store and quick to deploy, but it can kink; suction delivery costs more, but it is far more robust and kink-resistant. We compare them in layflat hose vs suction delivery hose.
Watch the video below to see the difference between suction delivery hose and layflat hose in real use:
Why we take you through this process
By taking a couple of minutes to understand the water type, head height, distance, pipework, power supply and whether it should run automatically, we can help make sure the pump you buy will actually do the job when it matters. You can make a start yourself with the Pump Finder, and for a controlled source rather than drainage, see surface pump vs submersible pump.
If the pump is a vital part of your flood resilience setup, you should always have a backup or spare. Pumps are mechanical devices, and while we choose to sell the best models available, mechanical items can fail, seize, and power trips happen. Having a second unit ready to go is often the difference between a close call and a flooded property.
Where a scheme needs proper calculations rather than product selection, that is engineering design, not advice, as we explain in when pump advice becomes engineering responsibility, and our Engineering Review Service can help.
