What We Wish Every Homeowner Knew About Household Water Pumps
If your home relies on rainwater, chances are you've got a pressure pump doing one of the most important jobs around the house.
At All Done Plumbing, most of the pump work we do falls into one of two categories.
The first is helping people who are building a new home on a rural property and need a reliable pump for their rainwater system.
The second, and probably more common, is the dreaded phone call:
"We've got no water. I think our pump has died."
The truth is, pumping can become incredibly technical. But for the average household with a rainwater tank supplying the home, it doesn't have to be overcomplicated.
For this article, let's keep things simple. We'll assume you're pumping from a rainwater tank, there's no significant suction lift involved and you're not trying to run a large irrigation system.
Here are the things we wish every homeowner knew.
1. Every basic pump starts out needing control
A pump does not think for itself.
In simple terms, an electric motor drives the pump. If power is supplied and there is no control system, the motor runs. If power is turned off, it stops.
That is why every domestic water pump needs some form of automation.
Today, most quality household pump packages include an electronic pressure controller.
This controller does the thinking for the pump.
It detects when you open a tap and automatically starts the pump.
When you close the tap, it shuts the pump down again.
It also provides valuable dry-run protection. If your rainwater tank runs empty, the controller helps prevent the pump from running without water, which can cause serious damage.
Without this type of control, you would be running outside to switch the pump on every time you wanted water and turning it off again afterwards.
2. If the pump wakes everyone up at night, consider a pressure vessel
This is one of the most worthwhile upgrades you can make to a household pump system.
A pressure vessel stores pressurised water.
That means when someone flushes the toilet during the night or quickly washes their hands, the water can often come from the pressure vessel instead of immediately starting the pump.
Depending on the size of the pressure vessel and how it is set up, you may be able to use 10, 20 litres or more before the pump needs to start.
The result is:
Quieter nights
Less pump cycling
Reduced wear on the pump
Longer pump life
It is one of those upgrades that people rarely regret.
3. Buy the pump for the way your family actually uses water
One of the biggest mistakes people make is buying a pump that is either too small or much bigger than they need.
Start by asking one simple question.
How many fixtures are likely to be running at the same time?
If you are a couple living alone, you may only ever have one shower or one tap operating.
A larger family might have:
Two people showering
The washing machine running
The dishwasher filling
Someone using the kitchen sink
Rather than counting taps, we prefer thinking about flow.
As a rough guide, allow around 15 - 20 litres per minute for each shower.
If you want to comfortably run three showers at once, you will need a pump capable of supplying around 45 litres per minute.
Once you start getting into those flow rates, you are looking at a significantly larger domestic pump.
4. Don't forget about height
Flow is not the only thing that matters.
If your house is two storeys, or your pump has to push water uphill to the house, that extra height needs to be considered when selecting the pump.
The higher the water has to travel, the harder the pump has to work.
That is why pump selection is based on both flow and head, which is the height the pump needs to push water.
5. Don't be fooled by the numbers on the box
This is probably the biggest misunderstanding we see when people compare pumps.
Manufacturers often advertise two impressive numbers.
For example:
Maximum Head: 65 metres
Maximum Flow: 55 litres per minute
It is easy to assume the pump can produce 65 metres of head while delivering 55 litres per minute.
It cannot.
Those are two completely separate maximums.
You will never achieve both at the same time.
As your system requires more pressure, for example pumping uphill, the available flow decreases.
As your system requires more flow, for example several showers operating together, the available pressure decreases.
Every pump follows what is known as a pump performance curve, where pressure and flow constantly trade off against one another.
It is one of the most confusing concepts in pumping, not just for homeowners but sometimes for plumbers too.
That is why simply buying the pump with the biggest numbers is not always the right answer.
6. Bigger is not always better
Another common misconception is that if a pump is capable of producing very high flows, it should always operate there.
It should not.
Pumps generally perform best somewhere around the middle of their performance curve.
Operating continuously at maximum flow can cause problems such as cavitation, where tiny vapour bubbles form inside the pump and gradually damage the impeller.
Likewise, operating constantly at extremely high pressure and very low flow is not ideal either.
A properly selected pump spends most of its working life somewhere in the middle of its operating range.
That is where it delivers the best efficiency, the longest lifespan and the most reliable performance.
7. The pipework matters just as much as the pump
This catches many homeowners by surprise.
Installing a bigger pump does not automatically mean you will get more water.
Your plumbing pipework also has to be capable of carrying that flow.
For example, your pump might theoretically supply enough water for four showers.
But if the pipe supplying your home is undersized, it becomes the restriction.
Upgrading the pump alone will not fix the problem.
The entire system has to work together.
8. Cheap pumps can become expensive
There are plenty of inexpensive pumps available online and through large retail stores.
Some are perfectly suitable.
Others may not be certified for drinking water use or may have limited local parts and service support if something fails.
When your household depends on that pump every single day, reliability should be one of the biggest considerations.
We generally recommend choosing a quality pump from a reputable manufacturer with good local support.
9. Variable speed pumps are worth considering for larger households
Variable speed pumps are not necessary for every home, but they are definitely worth considering in the right situation.
If you have a large household with very different water demands throughout the day, a variable speed pump can make a noticeable difference.
Instead of simply switching on and off, a variable speed pump adjusts its motor speed to match demand.
That means it can respond differently when someone is just washing their hands compared with when multiple showers, taps and appliances are running at once.
The result is smoother pressure, reduced cycling and a system that feels less noticeable in day-to-day life.
And that is really what we are chasing with a good household pump system.
The less you notice it, the better it is doing its job.
10. A pump is not commissioned just because it turns on
One of the biggest mistakes we see is assuming a pump is installed correctly simply because it starts and stops.
Proper commissioning is much more than that.
A correctly commissioned pump should be checked to ensure it is operating within its intended performance range.
That includes things like:
Correct suction pipe sizing
Removing air from the suction line
Installing check valves where required
Checking operating pressures
Confirming the pump is working within its performance curve
Installing a pressure gauge to assist with setup and future fault finding
A poorly commissioned pump might still work.
But it may be operating inefficiently, using more electricity than necessary and wearing itself out long before it should.
Household pumping does not have to be complicated, but it does need to be done properly
This article is meant to be a bare-bones explanation of household pumping.
There is much more to pumping than what we have covered here.
As soon as you get into systems with hugely varying flow rates, significant suction lift, long pipe runs, pumping down a hill, complex rainwater setups or irrigation demands, things can get complicated very quickly.
That is why it is important to speak with someone who understands pumps, pipework and how the whole system works together.
At All Done Plumbing, we install and service household pump systems throughout Inverloch, Bass Coast and South Gippsland. Whether you are building a new home on tank water, replacing a failed pump or trying to improve an existing system, we can help you choose the right solution for your property.
A well-designed pumping system should provide years of reliable service. Get the basics right from the beginning, and you will spend less time thinking about your pump - which is exactly how it should be.