Do you need a water tank with a heat pump?

Author: Kaylah Murphy  |  Last update: Wednesday, October 15, 2025

While a hot water tank is typically required when using an air source heat pump to provide domestic hot water, an ASHP can be installed without a water tank but would only provide heating and another system would be required to provide hot water.

Can I use a water pump without a water tank?

You can't run it that way without a tank, no. As mentioned it'll kill your pump. What you can do, if you're careful is to ensure your spigot stays open and use the breaker to turn the pump on and off with that (giving it at least a minute of run time each time) to draw water from the well to fill pails and such.

Do heat pump water heaters have tanks?

You can purchase a stand-alone heat pump water heating system as an integrated unit with a built-in water storage tank and back-up resistance heating elements.

Does a heat pump need water to run?

A mixture of water and anti-freeze is pumped around the ground loop and absorbs the naturally occurring heat stored in the ground. The water mixture is compressed and goes through a heat exchanger, which extracts the heat and transfers it to the heat pump. The heat is then transferred to your home heating system.

Can you run out of hot water with a heat pump?

If you want to operate the heat pump water heater on the cheaper off-peak electricity tariff, when it will mainly heat the water overnight, it's important that the system is sized so the amount of water you heat overnight meets your daily needs. If it's too small, you could run out of hot water.

Will I need a water tank with my heat pump?

Can you have a heat pump without a hot water tank?

When using an air source heat pump for heating or cooling purposes only, a hot water tank isn't typically required, but another system for providing hot water will be needed.

What is the downside to a heat pump?

It's expensive to install a heat pump

They cost considerably more than a gas installation. Nevertheless, grants are available to reduce the purchasing cost, which is not the case with gas installations. However, even with such grants, the heat pump is still at least 20% more expensive.

Why do heat pumps need a water tank?

Since the primary goal of heat pumps is to heat the space, it's difficult for them to supply enough hot water at the same time. The demand to produce hot water isn't quick enough. One way to get around this problem is to store hot water in a cylinder until it is needed.

What are the disadvantages of a heat pump hot water system?

While there's not a lot of disadvantages, there is one main one: the upfront cost. Getting a great, highly efficient heat pump means shelling out around $5,000. That'll pay for itself over time, and you can get some money off through rebates, but it's still a significant amount of money.

Will a water pump burn up without water?

The leading cause of pump burn out is from running dry. Submersible pumps require water to keep cool and maintain the proper operating temperature. If the water level drops below the impeller (also known as the rotor), the motor will overheat and burn out.

Can a heat pump replace a water heater?

Research has shown that if all residential electric water heaters were replaced with heat pump water heaters, the energy cost savings would jump to $12 billion annually, and 140 billion pounds of greenhouse gas emissions would be prevented annually.

What is the difference between 120 volt and 240 volt heat pump water heater?

The 120V option is versatile, energy-efficient, and perfect for small to medium-sized households. On the other hand, the 240V option is suitable for larger families with high hot water demand, offering faster heating and better performance in colder climates.

Which is better, a tankless or heat pump water heater?

Tankless water heaters work best in homes where room is limited. Heat pump water heaters are more energy-efficient. Installing a tankless water heater often requires new plumbing. Tankless water heaters have a longer life span.

Do you need a pump with a water tank?

While gravity-fed systems work well in some situations, a pump becomes crucial when: Water needs to flow uphill. Distribution points are higher than the tank. The tank is positioned below the usage area.

What happens to a water pump if there is no water?

Depending on how the pump is powered you would see a spike in RPM if no water is fed. Also system temps would rise relatively quickly. If the rotor is made of polymers it will degrade quickly if dry, less of a concern for the bearings since they're not in contact with the coolant.

Can you run a water pump without water?

When a pump runs dry, it generates heat and force it was never designed to handle, leading to wear and tear that can quickly add up to inflated repair costs. Avoiding dry running is highly important, but it makes sense to learn how negative it can be in order to fully understand the severity of the phenomenon.

Why do people not like heat pumps?

Heat pumps loose their effectiveness (not to be confused with their efficiency) the colder it gets outside forcing you to either use the electric heat or stay cold. Systems that are designed poorly so the ductwork is too small resulting in a lot of air noise and drafts that is not as warm.

Is it worth getting a heat pump water heater?

With combined local and federal* incentives and lifetime fuel cost savings when compared with tank electric, tank gas, and tankless gas, ENERGY STAR certified heat pump water heaters can have impressive lifetime cost and energy savings.

How much does it cost to install a heat pump water heater?

Up front, a new traditional cylinder costs around $4000 to buy and install (compared to $7,000 for a hot water heat pump).

Can you run a shower off a heat pump?

Yes, properly designed heat pump systems can offer full heating and hot water, qualifying for schemes like the Boiler Upgrade Scheme. Unvented cylinders ensure hot water at 50-65°C, suitable for showers and baths.

Do heat pumps use a lot of water?

The system pulls the water from an aquifer into the piping and into the heat exchange pump to transfer heat from the ground into the home. This system consumes no water; all water used is returned back into the ground.

Do you run out of hot water with a heat pump?

Heat pumps can't heat up hot water on demand like a combi boiler, so they require a hot water cylinder. A cylinder stores heated water so it's ready to use when you need it.

Why don't contractors like heat pumps?

Contractors avoid deploying more heat pumps because of money. I'm told they are too expensive to sell, when a furnace is another, cheaper solution. Additionally, the incentives are diverse in their scope and in some cases daunting to navigate for both contractors and customers.

At what temperature is a heat pump useless?

Heat pumps do not operate as efficiently when temperatures drop to between 25 and 40 degrees Fahrenheit for most systems. A heat pump works best when the temperature is above 40. Once outdoor temperatures drop to 40 degrees, heat pumps start losing efficiency, and they consume more energy to do their jobs.

What is more efficient than a heat pump?

In colder climates, 95% efficient gas furnaces fare better than ENERGY STAR® heat pumps. And, due to the relatively lower cost of natural gas versus electricity, lifetime operating costs should be considered as well.

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