Most pumping mistakes are surprisingly easy to avoid once you understand what’s really going on. The truth is, pumps follow the same basic rules of physics and engineering as plenty of other bits of kit we use every day, the difference is, most people haven’t needed a water pump before. Or, if they have, it’s usually been running quietly in the background, doing its job without anyone noticing… until of course something goes wrong.
This isn’t a technical guide full of jargon. It’s simply a collection of real-world lessons, the kind that come from experience, which can save you time, money, and frustration.
A lot of people assume a bigger pump must be better, but this isn’t the case. Think Jeremy Clarkson shouting “Speed and Power”, well, that isn’t what we want with water pumps, we want a well matched and suitably specified option.
If the pump’s too powerful, it’ll will either end up running dry if a manual pump, or, if automatic, keep switching itself on and off quickly because it’s emptying a chamber too quickly. This constant starting and stopping (often called short cycling) wears the pump out much faster than if it were to run for extended periods, with the water flow cooling the motor. This we can all relate to town driving, (stop-start), causing more wear on a car than cruising along a motorway in a high gear and low revs.
You also don’t want to overload the area you are discharging to.
Given pumps are mechanical items we’ll again relate it to cars or driving. You won’t get there any faster by accelerating rapidly, nearly hitting the car in front then jamming your brakes on. Better to stay trundling along at a safe distance with limited wear on the engine or brakes. The same is true for water pumps and the associated flow rate.
If you choose a swimming pool pump that’s too large, you can also end up with an electricity bill higher than needed, and even overloading the pools filtration system.
If the pump is too small, you can either end up with a problem forming (imagine here if a sewage pump was undersized and couldn’t keep up with the inflow, yuck!), or even if a pump was being used in a flood and it couldn’t keep up with the flow rate of water entering, the flood depth would increase. Alongside this, you also must ensure you have enough power to pump the distance you’re requiring the pump to discharge the water too.
The key is finding the right balance. Match the pump to the job: the height, the distance, and the amount of water you actually need to move.
This is why understanding the pump performance curve is important, which can be read about in another blog of ours here: Pump Curves Explained: How to Understand Flow Rate and Head Height.
This is one that catches a lot of people out. Head height isn’t just about how high the water has to go. It’s everything that gets in the way, the bends, the hose, and the friction as the water moves through the pipework.
As a rough guide, every 10 metres of hose lying flat is roughly the same as pumping one metre upwards. So, if you’ve got a long run of hose going across a garden or up a slope, that resistance adds up quickly.
If you ignore it, your pump might seem weak, when it’s working exactly as it should, it’s having to overcome physics!
Over the years, we have seen a number of setups where the hose or pipework is the problem, not the pump.
Garden hoses, for example, are only about 13mm wide, so you’d lose most of your flow before the water even gets out the end. For most jobs, especially where floods are involved, you’re better off using proper Suction Delivery Hose or Layflat Hose.
Suction Delivery Hose doesn’t kink and keeps the flow rate strong. Layflat Hose is easier to roll up and store. Which one you use depends on the job, but a garden hose usually isn’t the answer.
If you have a fixed installation, it’s also important to consider the requirements before specifying the pump or pipework, otherwise you could end up with the incorrect pipe size, or connections for the required job. Fundamentally where there are specific requirements, such as a pumped drainage system using a water pump, a Consulting Engineer should always be involved to determine the specifics first. It can feel frustrating to pay for expertise “up-front”, but it will be worth it.
It’s an easy mistake to make. You start the pump, the water drops, and before you know it, it’s running dry. Most pumps rely on water to keep the motor cool. Without it, they can overheat or damage the seals in minutes. Of course, automatic pumps are less exposed to this, but it can still occur if the float switch gets snagged.
Some pumps, like the Tsurumi LSC1.4S Puddle Pump, are designed for really shallow water and can handle it for extended periods of time, but most can’t. Always check before switching one on, if it needs water, make sure there is enough water for it to function.
Pumps don’t need much looking after, but they do need some.
Give yours a quick run every now and then, especially before bad weather. Check that the float switch moves freely and that nothing’s blocking the inlet. It takes five minutes and can stop a lot of problems later on.
Also, simple things help... for instance, if you’re using a pump to drain a hot tub, or swimming pool (that are chlorinated), flush the pump through afterwards with clean water.
This sounds obvious, but it’s one that’s easy to miss. Before you start pumping, make sure the water actually has somewhere to go, a drain, ditch, soakaway, or safe discharge point.
Without considering this early on, you can’t determine what length of hose you’d need, to help determine what pump may suit your requirements.
A well-chosen pump should last for years if it’s used properly. Take the time to get the setup right, the right pump, the right hose, and the right placement, and it’ll quietly do its job without much fuss. If you’re purchasing a replacement pump, one of our first questions would always be – how long it has lasted. Whilst there are undoubtedly some poorly made pumps with limited lifespans available from certain online stores, fundamentally if the pump has failed prematurely there can often be a factor driving this, and replaced with a like for like, the same failure could occur again.
If you’re unsure which setup is best, just ask. At floodandwaterpumps.co.uk, we’re always happy to help. Sometimes a quick chat saves a lot of time (and money) later on. And, if the requirements are specific, we’ll be able to pass you to a Consulting Engineer at our sister company FPS Environmental Ltd who advise a site visit to determine the requirements, or other calculations as necessary.
In property-level protection schemes, barriers may seal doors and openings, but water can still enter through walls, floors, and service routes. Measures like repointing or tanking reduce this, but rarely eliminate it entirely.
The EGO 500 SELS uses electronic water-sensing probes rather than a traditional float switch. This allows low level automatic operation in shallow sumps or tight chambers where floats may otherwise jam, or stick - whilst also not pumping as low...
If it’s a critical part of your flood resilience setup, treat it like any other critical bit of kit:
accessible, serviceable, protected, and backed‑up.
