You cannot run out of the actual water supplied to your home with a heat pump, because the tank refills from your mains water line the moment you draw water off. What you can run out of is hot water if you use more than the tank holds before the system has had time to reheat it.
That is true of any storage system, and most Perth homes avoid it easily once you understand how a heat pump manages its supply.
A heat pump is an efficient way to make hot water, and staying in hot water is mostly about size and timing.
Can a Heat Pump Actually Run Out of Hot Water?
Yes, a heat pump hot water system can run out of hot water, in the same way a gas or electric storage tank can. The difference is worth being clear about. Your water supply never stops, but the hot water inside the tank is a fixed amount.
When you use hot water, it leaves the storage tank and cold water flows straight in to replace it. If several people take long showers one after another, that incoming cold water mixes with the hot water still in the tank, and eventually the shower turns cold.
High simultaneous demand can empty the tank before it has time to recover, which is the most common reason people think their system has failed when it is simply catching up.
Why a Heat Pump Might Run Out of Hot Water
If your system keeps running short, one of a few things is usually behind it.
An Undersized Tank
A small or undersized tank is the most common cause. A good sizing guideline is about 50 litres of tank capacity per person, so a busy household that needs more hot water than a small cylinder holds will empty it quickly. Small households can often manage on a compact cylinder, but a larger family needs the capacity to match.
As a rough guide, a 270-litre tank supports five to seven consecutive showers. Having a larger tank installed is the simplest way to reduce the risk, and while it adds a little to the upfront cost, our guide on what size heat pump you need walks through it.
High Simultaneous Demand
Even a well-sized system can be caught out when everything runs at once. Back-to-back showers, the laundry, and the dishwasher all drawing hot water together can empty the tank faster than it recovers, before it can heat water back up, which can take an hour or more.
Spreading that demand out gives the system room to keep up.
Cold Weather and Slow Recovery
Because a heat pump pulls warmth from the air, absorbing heat from the ambient air to warm your water, recovery slows when the surrounding air is cold. Efficiency and recovery time both drop in colder climates, though quality units still operate efficiently in temperatures as low as -10°C.
Perth’s mild, warm climate actually favours heat pump efficiency, so recovery here is rarely an issue.
Timer Settings and Maintenance
Incorrect timer settings can leave the tank half-heated before your busiest time of day. Beyond that, a faulty thermostat, sediment build-up, or a dirty air filter or blocked fan can all restrict output and stop the unit heating properly.
Keeping up with basic maintenance protects performance, and our guide to the factors that impact your heat pump’s performance covers what to watch for.
How to Make Sure You Never Run Out of Hot Water
Hot water heat pumps rarely leave Perth homes when they are set up well. A few simple steps keep the hot water flowing:
- Size the tank to your household, allowing around 50 litres per person.
- Use the boost mode ahead of high-demand periods so the tank is full of warm water when you need it.
- Let the backup heating element assist during peak usage.
- Set the timer to finish heating before your busiest time of the day.
- Stagger long showers rather than running them all at once.
- Keep the air filter clear and the unit well maintained so it recovers quickly.
It also helps to run the system during the day, when a heat pump can reheat cheaply on solar electricity, cutting your water heating costs and using less energy.
You can read more in our guide to pairing heat pumps with solar panels.
What About Water Leaking From the Unit?
If you have noticed water pooling around the unit rather than running short at the tap, it is almost always normal condensation. A steady leak, water coming from the tank itself, or pooling that never stops is worth a service check, as it points to something other than condensation.
For most Perth homes, running out of hot water comes down to sizing and settings, both of which are easy to get right.
A well-sized heat pump is an energy-efficient water heater that uses much less electricity than a traditional system, so you get reliable hot water for less.
Never Run out of Hot Water Again with Eurosun’s Heat Pumps!
Running out of hot water almost always comes down to two things: the right tank size and the right settings.
Get both correct and a heat pump will keep your Perth home in reliable hot water all year round.
The team at Eurosun can size a system to your household, set it up to recover cheaply on solar, and make sure it is matched to how you actually use hot water.
You get an energy-efficient system that costs less to run and keeps the hot water flowing, even during the morning rush.
Talk to Eurosun today and never run short again.