Failures, Complaints and Official Sources
Heat pump hot water problems: noise, running out of hot water, cold weather and error codes
The most common heat pump water heater complaints in Australian homes, what usually causes them, what you can check safely and when it is a warranty or consumer guarantee issue.
Most heat pump hot water complaints in Australia come down to a handful of causes: noise near bedrooms, running out of hot water because the tank is too small or the timer window too short, slow recovery in cold weather, higher-than-expected bills because the unit runs at the wrong time or on its backup element, and condensate or relief valve water that looks like a leak. Many can be fixed with settings, re-siting or a larger tank; others are faults covered by the warranty or the Australian Consumer Law. This guide explains what to check and when to call the installer. It is part of where to get help.
Problem and likely cause
| Symptom | Common causes | What you can check |
|---|---|---|
| Hums or drones at night; neighbours complain | Location near bedrooms or in a narrow passage; unit running overnight on off-peak | Timer settings; whether it can run during the day; ask about re-siting or acoustic measures |
| Runs out of hot water | Tank too small for household; timer window too short; set temperature low; tempering valve fault | Household size vs tank; timer; check with installer |
| Slow to reheat in winter | Air source performance falls as air temperature drops; some models switch to element | Model's operating temperature range; frost or ice on the evaporator |
| Bills higher than expected | Running on peak tariff; backup element operating often; controlled-load not set up | Tariff and timer; look for element or "boost" mode on the controller |
| Water dripping under the unit | Condensate from the evaporator (normal); relief valve discharge (normal in small amounts) | Whether the drain lines go to a proper drain; large or continuous discharge needs a plumber |
| Error code on display | Sensor, fan, compressor or flow faults | Note the code and look it up in the manual; contact the installer or manufacturer |
| Hot water smells | Water quality or anode issues | Contact the installer; may need servicing |
Noise: the most common complaint
Heat pumps have a fan and a compressor. Their sound is usually described as similar to an outdoor air conditioner unit. Problems arise when:
- the unit is placed under a bedroom window, yours or a neighbour's;
- it runs overnight on an off-peak tariff;
- it sits in a narrow side passage where sound echoes off walls and fences.
Options, roughly in order of cost:
- Change the timer so it runs during the day (often cheaper if you have rooftop solar).
- Ask about anti-vibration feet or mounts and checking the fan.
- Re-site the unit or choose a split model with the compressor further away.
Some states and councils set limits or times for residential equipment noise. If a neighbour complains, talk first; check your state environment protection authority's guidance on residential noise.
Prevent this at the quoting stage by agreeing the location in writing. See the heat pump hot water cost guide for placement factors.
Running out of hot water
| Check | Why |
|---|---|
| Tank size vs people | A 2-person tank in a 5-person house will run out |
| Heating window | If the unit runs only for a few off-peak hours, it may not fully reheat |
| Set temperature | Lower settings mean less usable hot water after mixing |
| Showers back to back | Heat pumps recover more slowly than gas instantaneous systems |
| Tempering valve | A faulty valve can limit hot water flow or temperature at taps |
If the tank was sized by the installer for your stated household and it consistently runs out, raise it as a fitness-for-purpose issue under the consumer guarantees (warranty guide).
Cold climates
In Canberra, Tasmania, alpine areas and cold inland towns, check before buying:
- the model's minimum operating temperature;
- whether it switches to an electric element below a certain temperature (and how often that might happen where you live);
- defrost behaviour;
- whether the manufacturer markets it for cold climates.
STC numbers differ by postcode zone, reflecting climate. A model's lower STC count in a cold zone signals lower modelled savings. See the STC guide.
Bills higher than expected: a worked check
Illustrative example. A household expected the heat pump to use about 850 kWh a year. Its bill suggests about 1,700 kWh.
- Check the controller: is the backup element (boost) on all the time? If so, the unit is acting like an electric storage tank for part of the time.
- Check the timer: is it heating at peak rates in the evening?
- Check the tariff: is the circuit on controlled load as planned?
- Check hot water use: has household use changed?
At 32 c/kWh, the extra 850 kWh costs about $272 a year. Fixing settings can make a real difference. Use the running-cost guide to recalculate. Figures are illustrative.
When it is a warranty or consumer guarantee issue
- Repeated error codes or a compressor failure: contact the seller or manufacturer.
- A tank leak: switch off and call the installer; tank warranties are often separate from compressor warranties.
- Faulty installation (drains not connected, unit not level, wrong valve): the installer's responsibility under the services guarantees.
Keep a record of dates, error codes, photos and calls. See where to get help for the escalation path, and common installation mistakes for problems that start on day one.
Frequently asked questions
Is water under the heat pump normal?
Small amounts of condensate are normal, and relief valves discharge a little as water heats. Continuous flow or a puddle that keeps growing needs a plumber.
Can I turn off the backup element?
Some models let you adjust it. Turning it off may save energy but could leave you short of hot water in cold weather. Follow the manual or ask the installer.
How often does a heat pump need servicing?
Check the manufacturer's manual. Relief valves and anodes may need periodic checks, and the air intake should be kept clear.
Will my heat pump work during a blackout?
No. Like any electric water heater, it needs power, though the tank stays warm for a while.
Official sources
- Clean Energy Regulator — heat pump register and postcode zones
- energy.gov.au — hot water systems guidance
- ACCC — consumer guarantees
- NSW Fair Trading and Consumer Affairs Victoria — complaints
