Running cost of a garden water pump

The purchase price is just a portion of the total costs of the pump in the long term.

Start by comparing performance first – when you go on your investigations take a metric conversion table or calculator with you and a pencil and paper. The most efficient level of performance as indicated on a typical pump performance table is around halfway on the performance curve if it is mapped out on a graph, or between 40% and 80% of the full flow with no restriction.

Once you have two pumps or more comparable on performance, say with the same performance at pumping to 1 metre, they might have distinctly different power consumption levels, which might make a significant difference in costs over the life of the pump if it is running all the time.

Running cost of a garden water pump

Running costs = (Watts x Hrs/1000) x KWH rate.

In my experience I have had two pumps of very similar performance, but one was rated at 80watts and the other (a very modern one) at 15Watts. Over the period of a year with a KWH unit rate of 9p, the 80Watt motor would have cost £26.28p to run and the 15Watt would have cost £4.92p. So add this into an equation for the real costs of your pump by simply multiplying by the length of the guarantee and adding it on to purchase price of the pump.

Now, guarantees are another factor of the price.

One year long guarantees are a thing of the dim and distant past. The average punter nowadays is coming to expect 3 or even 5 year guarantees. To mean anything at all this must be ‘continuously rated’ i.e. if it is a 5 year guarantee the pump must still be guaranteed to run for 5years continuously non-stop.

So taking this into account, if guarantees are any indication of life expectancy, they must surely be added to the equation in cost estimates. These two pumps I had in mind before, the 80watt pump had a three year guarantee and the 15watt had a 5year guarantee. It was then quite possibly going to last another two thirds longer than the first one, so in fairness two thirds of the cost of the first needs to be added to its original cost to be a comparison.

At this rate they ought to have been giving the first one away in order to make it a viable comparable economic choice.

Over the coming months I am going to be testing a number of popular makes of pump against each other that purport to have similar performance figures and putting them through their paces for the various tasks they seem most suited. The conditions, unfortunately for the manufacturers (and for myself who will be carrying out the tests) are that they wont be carried out in sterile pristine tanks.

It will be the muck and mire of an ordinary garden pool at Blagdon Water Gardens – the original home of the pump that changed the playing field. Here will be all the detritus and grime to block them up as in the real world and I will undoubtedly have the cold numb fingers that will struggle to dismantle them for maintenance. To start with we will try out small pumps moving from 1000 to 1500 litres per hour that give a good fountain or perhaps provide the flow for a small waterfall.


In the beginning there was Otter from Beresford and a whole lot of things that looked like headless Daleks. These were all the pumps we had for water gardens for pumping water up fountains and to the top of waterfalls; magical days when most people believed fountains were powered by the mains water supply.

But some of us knew better.

Otter pumps, made in Britain, had been with us for decades and had built up a reputation for good value for money and reliability. They seemed to be the only submersible pumps specifically designed for small domestic water gardens.

They came in a number of sizes all looking very much the same; a very solid fist sized blob of plastic with a watering can rose style of attachment. The basic price of the most popular model of £46.93p for which you could expect to get 330 gallons an hour (roughly 1650 litres) down a 3ft (less than a metre) high waterfall roughly 4 to 5 inches (10-12.5cms) wide.

The top of the Otter range (Otter 52) could double that performance for over £128.

But you could get more performance for less money if you resorted to the ‘Dalek’ brigade. They were upright cylinders with an inlet grill in the most unsuitable place, on the bottom, and they came with names like the ‘Jumbo’ that could do a respectable 1000 gallons to 3 feet for around £90 or ‘Torrent’ with an impressive 2000 to the same height for £180.

I remember Blagdon Water Gardens used to sell a beast called the ‘Barracuda’ that was top of their range. It could suck a 4000 gallon pool dry in less than 60 minutes but needed the capacitor already fitted in its cable and a special ‘starter’ switch to provide an extra wallop of power to get it moving.

Once the water was up and going the electricity metre in your home would rattle round the numbers like a fruit machine. This was all yours for the princely sum of £268.27p.

Many of these pumps had no particular maker’s name attached. Why?

Because this was an embryonic industry and people were still inventing or cobbling together ‘good ideas’ from bits and pieces, and one of these was to sell submersible pumps that were really designed to sit in cellars in case of a flood.

Well, that’s all there was guv’ner.

These pumps were ‘repackaged’ and sold for a purpose for which they were quite suitable, as long as you did not expect them to perform 24/7 or work much beyond the day their guarantee expired. Their problem was, and still is, for this sort of pump the shaft that drives the impellor that shifts the water up the pipe.

This comes from the centre rotor of the electrical motor with all its live wires and contacts out into the wet outside world through a small bearing and seal, that was generally sealed in place itself and therefore un-replaceable. It is this bearing and seal that the life of this sort of pump depends upon.

When the bearing and seal went on that old ‘Barracuda’, because it was oil filled there was little short of an ecological disaster. Taking into to consideration the temperature fluctuations and the variety of materials these pumps were made of, it is surprising they last as long as they do. The Otters somehow had overcome this problem with only great care on the quality control. However when the competition from the cheap ‘pretenders’ got fierce, this must have slipped because reliability became a thing of the past and sales of the Otter died.

Now we are not talking ancient history here, this is 1979-80, 25years ago, the height of the Thatcher era with all the associate rampant inflation, but despite that, prices nowadays in relation to pumping performance have hardly changed. There were still more formative years in the eighties to come as experiments in cheap pump design kept the prices low and Beresford out of business.

Then a pump came on the market that changed everything- the Blagdon Amphibious Pump.

This was a pump that wasn’t designed for cheapness … at last service and efficiency were back. Based on the tried and tested design of a central heating pump, it was capable of running silently day-in-day-out for not just a few months, but for years and years. It had no shaft and no seals. All the electrical contacts and wires were sealed away in a solid cylinder of plastic resin.
The impeller was glued to the rotor, which was a flat disc outside the motor and driven by the magic of electro-static. There was only one hard ceramic bearing, which could be changed in less than 5 minutes. This effectively made the pump immortal.
Introduced in 1986 there are still some of the original models still running fountains and waterfalls. The only thing that kills them is the rubber perishing on the cable or leaving them out in the hot sun. Here at last was a product that was worth having, and the fact that it swept through the sales of pumps throughout Europe it was a signpost to the burgeoning industry as to which way to go. People were prepared to pay for quality and products designed for the purpose for which they are intended.


Now it seems we have a golden age, because pumps are not only cheap there is a vast choice. In my local aquatic store I can find

  • Oase pumps,
  • Hozelock
  • Laguna
  • Pet a mate
  • Blagdon
  • Heissner and
  • Bermuda

This is a fraction of the total number of makes available.

But then Oase alone produce 49 different pumps for domestic water gardens, add that onto the 34 in the Hozelock stable you can see already how confusing the subject might be for the new comer.

As far as the individual pumps are concerned, although you do find ranges described as ‘All Purpose Pumps’ many of them are designed very often not just for water gardens but for a specific purpose within the water garden.

There are pumps that suit filters, others that suit fountains and some that have the real pushing power ideal for waterfalls. They usually come with a such mind boggling miasma of fittings, tubes and jets that you feel guilty only using a fraction of it and let it clutter up all the spare space in the garage until the next bout of Feng-shui hits.

There are some big companies now with lots of resources wrestling with each other for top end of the market. The end results are products of genuine efficiency and quality that look very similar to the likes of you and me. The ‘mechanical Armadillo’ or ‘space station platter’ look seems de rigueur at the moment, but looks aren’t everything. Performance varies enormously. Some pumps from some sources are outward copies of products that have been meticulously researched and developed, but inside the mechanics and the electronics may be very different.

So if you are thinking of buying a pump, don’t go on looks. Instead be sure precisely what you want it for. It could be for a combination of say waterfall and fountain, or waterfall and filter. The only combination that would be a compromise would be a fountain and filter (unless the filter is the ‘spider style’ in-pool filter – I’ll tell you about it soon, I promise)
In finding one that suits, compare it with the competition.

It is the information on the side of the pump box that offers most of the clues you need to help you decide, so scour that with the analytical and deductive mind of an old fashioned detective. Although it is often difficult to compare performance figures because they very often use different units of measurement, like for instance litres per minute to height in metres (Oase) as opposed to gallons per hour to a height in feet (Hozelock), if you take care to translate them, here are the clues as to how a particular pump is put together in the interior and also how it operates.

Ostensibly that doesn’t really concern you, although it may affect how easy it is to maintain, but it does reflect the reliability, the economy and indirectly the price, and very often not the price you pay at the aquatic store till. The plethora of look-alikes in exterior design that are cheaper to buy and may even purport to shift the same quantities of water will soon be seen to be charlatans dressed up in space age clothing.