Short answer
Heat pumps make a steady hum from the fan and compressor. Manufacturer figures in CHOICE's 2026 comparison run from 37 to 54 dB(A). Solar Victoria compares a typical unit to a fridge; the Victorian Government compares it to an air conditioner. Put it away from bedrooms and neighbours' windows, and set the timer to run in the day: in Victoria, heat pumps must not be heard in a neighbour's room late at night or early in the morning.
On this page
Whether heat pumps are noisy is one of the questions people search most about them, and the official advice is mostly about where the unit goes. A gas or electric tank is silent. A heat pump has an outdoor fan and compressor, and if it is set to an overnight tariff it runs while you are asleep. Placement and run times are both settled before installation, so that is the time to get them right.
How loud is a heat pump hot water system?
CHOICE compiled stated noise levels for 102 heat pump models in its May 2026 comparison. The figures run from 37 to 54 dB(A), and CHOICE notes that 40 dB(A) is about a whispered conversation and 60 dB(A) an average conversation (CHOICE). My count of that listing:
| Stated noise | Number of models |
|---|---|
| 37 to 39 dB(A) | 20 |
| 42 to 45 dB(A) | 23 |
| 46 to 48 dB(A) | 33 |
| 50 to 54 dB(A) | 18 |
| Not stated | 8 |
Two big caveats. CHOICE says it doesn't test heat pumps itself, and makers measure in different ways. The federal government's 2026 review says noise data is available from "some, but not all, suppliers, and are not provided in a consistent manner (nor measured on a consistent basis)" (Decision RIS). One brand measures at 1 metre in a lab, another at 3 metres, another doesn't say. A unit quoted at 39 dB at 3 metres can be louder up close than one quoted at 45 dB at 1 metre. Rheem's brochure, for example, notes the installed noise level "may be higher" than its lab figure.
Is a heat pump louder than an air conditioner?
The comparisons in government guides vary. Solar Victoria says "the decibel level of a heat pump is similar to that of a fridge" (Solar Victoria). The Victorian Government's buyers guide says heat pumps "generate noise comparable to an air-conditioner" (VEU buyers guide). The plumbing regulator agrees with the air conditioner comparison.
Where should a heat pump go?
- Away from bedrooms. Victoria's buyers guide says heat pumps "should not be installed close to bedrooms (outside a kitchen or bathroom might be more appropriate)".
- Away from neighbours. Victoria's Building and Plumbing Commission recommends positioning units away from bedrooms and "where they won't disturb neighbours" (BPC).
- Watch the height on integrated units. Your Home notes that on all-in-one units "the noisy component is located high up, allowing noise to carry over fences". The outdoor unit of a split system sits low, which helps (Your Home).
- Plenty of air. The BPC says units must go in well-ventilated areas, typically outdoors.
Are there rules on when a heat pump can run?
Yes, in several states. The rules I confirmed:
| Where | Rule |
|---|---|
| Victoria | Hot water systems and heat pumps are in the group that must not be heard in a neighbour's habitable room before 7am or after 10pm on weekdays, and before 9am or after 10pm on weekends and public holidays. A council officer can still find noise unreasonable inside those hours (EPA Victoria). |
| ACT | Limits measured at the property boundary in residential zones: 45 dB(A) from 7am to 10pm and 35 dB(A) from 10pm to 7am (Monday to Saturday; on Sundays and public holidays the day period starts at 8am). Units in multi-unit complexes may face lower limits. The rules cover hot water heat pumps (Access Canberra). |
| NSW | A new Noise Control Regulation started on 28 August 2026, changing the hours for air conditioners and pumps (NSW EPA). I couldn't confirm the exact hours for heat pump water heaters under the new regulation, so check with your council. |
I haven't checked the rules for Queensland, WA, SA, Tasmania or the NT. Ask your local council.
What should I ask before buying?
- What is the stated noise level, and at what distance and conditions was it measured?
- Where exactly will the unit go, and how far is it from my bedrooms and the neighbours' windows?
- Can it be set to run only during the day?
- Would a split system with a low outdoor unit suit this spot better? See all-in-one vs split.
Sources for this page
- Heat pump hot water systems: compare (manufacturer-stated data, updated 8 May 2026), CHOICE (non-profit). Last checked: November 2026.
- Decision Regulation Impact Statement: energy efficiency policy options for heat pump water heaters (April 2026), Energy Rating (Australian Government). Last checked: November 2026.
- Why choose a heat pump hot water system, Solar Victoria. Last checked: November 2026.
- Hot water buyers guide (Victorian Energy Upgrades), Victorian Government (energy.vic.gov.au). Last checked: November 2026.
- Heat pump installations (industry update), Building and Plumbing Commission (Victoria). Last checked: November 2026.
- Hot water systems, Your Home (Australian Government, DCCEEW). Last checked: November 2026.
- Residential noise, EPA Victoria. Last checked: November 2026.
- Snapshot: installation of air conditioners (noise limits), Access Canberra (ACT Government). Last checked: November 2026.
- Changes to the Noise Control Regulation, NSW Environment Protection Authority. Last checked: November 2026.
Every source used on the site is listed on the sources page.