Heat Pump to Gas Hot Water: Is It Worth Upgrading?
Heat Pump to Gas Hot Water: Should You Switch Back?
Compare both gas pathways before giving up the heat pump: gas storage keeps a tank, while instant gas removes the tank and heats water on demand.
A failed, noisy or disappointing heat pump can make gas look attractive, but changing technology also means giving up the heat pump's low electrical demand and any future STC pathway on an eligible replacement. Gas storage and instant gas solve different problems, so the right comparison starts with why you want to change, whether suitable gas is already available and what matters most to the household.
Does Switching Back to Gas Make Sense?
This is a preliminary guide only. Gas availability, pipe sizing, flue or clearance requirements, electrical supply, water demand, noise, location and licensing all need to be checked before a final decision.
1Why are you considering leaving heat pump?
2What gas supply is already at the property?
3Which gas style appeals more?
Guide only. A licensed installer needs to confirm gas type, gas pressure and pipe capacity, appliance location, combustion-air and clearance requirements, electrical supply where required, water flow, sizing, ventilation and current compliance requirements.
Can You Replace a Heat Pump With Gas Hot Water?
Yes, where the property has a suitable natural-gas or LPG supply and the selected gas appliance can be installed compliantly. The bigger question is whether changing back to gas actually solves a problem that a better replacement heat pump would not.
Gas Storage or Instant Gas: They Solve Different Problems
Do not treat "gas" as one product type. Gas storage keeps a tank and familiar stored reserve. Instant gas removes the large tank and heats water as it flows, which can be attractive where ground space and continuous delivery matter.
Stored Water + Gas Burner Recovery
Gas storage is the closest physical match to the heat pump because both use a ground-level tank. The existing heat-pump footprint may be useful, but the gas connection, flue or combustion clearances, valves, base and plumbing still need to suit the selected gas unit.
- Familiar stored reserve.
- Strong recovery can suit high-demand households.
- Requires a suitable natural-gas or LPG supply.
- Still carries standing losses from storing hot water.
Compact Continuous-Flow Hot Water
Instant gas removes the full-size storage cylinder and heats water on demand. That can reclaim the old tank footprint and avoid storing a large volume of hot water, but the appliance can have a much higher instantaneous gas input than older storage systems.
- Wall-mounted and compact.
- No large stored-water reserve to maintain.
- Flow rate must suit simultaneous household demand.
- Gas pipe capacity is especially important.
Why Would Someone Change From Heat Pump Back to Gas?
The strongest reasons are practical rather than efficiency-led. Gas can solve space, noise, recovery or personal-preference issues, particularly where a suitable gas supply is already connected.
Heat-Pump Noise Is a Real Problem
If the only workable heat-pump location is acoustically sensitive and relocation is not practical, gas can remove the compressor and fan from the hot-water installation.
Need to Free Ground Space
Instant gas can replace the full-size heat-pump tank with a compact wall-mounted appliance where the gas supply and site are suitable.
High Continuous Demand
A correctly selected continuous-flow gas unit can suit households that prioritise extended hot-water delivery without waiting for a storage tank to recover.
Gas Is Already Used Elsewhere
If the property is retaining gas for cooking, heating or other appliances, changing hot water back to gas does not create a new fuel connection by itself.
Existing Heat Pump Was a Poor Fit
An undersized, noisy or poorly located heat pump may have created a bad experience. The key question is whether the problem was the technology or that specific installation.
Simple Familiar Gas Replacement
Some households simply prefer an existing gas pathway and have a local installer familiar with that technology. Suitability and long-term fuel costs still deserve comparison.
Heat Pump vs Gas: Current Installed Today Starting Prices
The product price is only one part of the conversion. A switch to gas can add gas fitting, pipe upgrades, mounting, flue or clearance work, plumbing changes and electrical work for controls or ignition depending on the system.
Higher product cost than some gas units, but efficient operation, strong solar-PV integration and potential STCs on eligible replacement systems.
Current Installed Today heat-pump collection starting price. Product, installation and incentive treatment vary by model and location.
Gas appliance prices can start lower, but the conversion cost depends heavily on whether suitable gas is already present and whether the selected appliance needs gas-pipe or site upgrades.
Current Installed Today gas collection starting price. The live range includes both storage and instant gas systems.
Heat Pump vs Gas Storage vs Instant Gas
| Consideration | Replacement Heat Pump | Gas Storage | Instant Gas |
|---|---|---|---|
| Heating method | Transfers heat from surrounding air into stored water | Gas burner heats a stored tank | Gas burner heats water as it flows |
| Storage tank | Yes | Yes | No large storage tank |
| Ground-space need | Full-size cylinder | Full-size cylinder | Compact advantage Wall-mounted in many installations |
| Operating noise | Compressor and fan while heating | No heat-pump compressor or fan | Burner/fan operation depending on appliance |
| Gas supply | Not required | Suitable natural gas or LPG required | Suitable gas required; higher-flow units can need substantial gas input |
| Solar PV pairing | Strong advantage Can be scheduled into daytime generation | PV does not supply the gas burner | PV does not supply the gas burner |
| STCs | Eligible listed air-source heat pumps may qualify | No heat-pump/solar-hot-water STC pathway | No heat-pump/solar-hot-water STC pathway |
| Recovery / long draw | Depends on tank size, compressor recovery and boost control | Stored reserve plus gas burner recovery | Continuous-flow advantage Subject to rated flow and simultaneous demand |
| Best reason to choose | Efficiency, PV integration and lower electricity demand | Stored gas recovery where gas already suits the property | Compact footprint and continuous-flow delivery where gas supply is adequate |
Before Choosing Gas, Check the Gas Supply Properly
A gas meter or LPG bottles at the property do not automatically mean every gas hot-water system can be connected without changes. The selected appliance has to suit the gas type, available pressure, pipe size, total connected load and installation position.
Natural Gas Connection
If natural gas already serves the home, the installer still needs to confirm that the meter, regulator and pipework can support the selected hot-water appliance alongside other gas loads.
LPG
LPG models and regulators must match the fuel supply. Ongoing bottle logistics and fuel cost should be considered before converting an electric heat pump back to LPG hot water.
Instant Gas Demand
Continuous-flow systems can have high instantaneous gas input. A larger flow-rate upgrade can require pipe changes even if a smaller gas appliance already operates at the property.
Gas Storage Demand
Gas storage usually has a different input profile from instant gas, so appliance selection should still be checked against the existing gas network and other appliances.
Location & Clearances
Gas appliances have combustion, flue, terminal, opening and service-clearance considerations that are different from the heat pump they replace.
Electrical Supply May Still Matter
Many instant gas units and some gas systems require electricity for ignition, controls or fans, so converting to gas does not necessarily remove electrical requirements altogether.
Have Solar PV? We Would Strongly Recommend Comparing Another Heat Pump First
A replacement heat pump can be scheduled to operate while rooftop solar is generating. Switching to gas moves the water-heating energy demand away from electricity that your home may already generate and back to purchased fuel.
Heat Pump + Solar PV
Daytime operation can use household-generated electricity while the heat pump's lower electrical demand preserves more PV for other loads.
Gas Storage + Solar PV
Solar electricity does not directly provide the gas burned by the storage water heater, so the hot-water load remains tied to purchased gas.
Instant Gas + Solar PV
The appliance avoids a large electric hot-water load but still relies on gas for normal water heating rather than using the home's daytime PV production.
If rooftop solar is already installed and the old heat-pump site remains workable, gas needs a strong practical reason to beat a replacement heat pump. For most otherwise suitable homes, we would keep the heat-pump pathway.
You May Also Be Giving Up an STC Pathway
Eligible air-source heat pumps can create federal Small-scale Technology Certificates when the exact model and completed installation satisfy current scheme requirements. Conventional gas storage and instant gas hot-water systems do not receive that renewable-hot-water STC pathway.
Replacement Heat Pump
Eligible listed models can qualify for STCs, subject to the system, installation date, location and scheme requirements.
Gas Storage
Conventional gas storage is outside the solar-water-heater and air-source-heat-pump STC categories.
Instant Gas
Continuous-flow gas hot water does not receive the renewable-hot-water STC pathway available to eligible heat pumps.
When Gas Storage Can Genuinely Make Sense
Gas storage is most defensible where the household wants a stored reserve, strong burner recovery and already has a suitable gas supply, while the heat-pump location creates a genuine problem.
Existing Gas Supply Is Already Suitable
The conversion is materially easier when natural gas or LPG is already available and the gas pipework can support the selected unit.
Heat-Pump Noise Cannot Be Managed
Where a quieter model or sensible relocation still cannot solve an acoustically sensitive site, gas storage can remove the compressor and fan.
Stored Reserve Is Preferred
Some households prefer a defined stored volume plus burner recovery rather than changing to continuous-flow operation.
When Instant Gas Can Genuinely Make Sense
Instant gas has a clearer practical advantage when freeing space or delivering long continuous hot-water use matters more than retaining a storage tank.
Ground Space Is Valuable
Removing the heat-pump cylinder can reclaim a substantial outdoor footprint when a compliant wall-mounted gas position is available.
Long Continuous Use
A correctly sized continuous-flow unit can keep producing hot water without depleting a storage tank, subject to flow rate, gas capacity and simultaneous demand.
Existing Gas Infrastructure Suits
The pathway is strongest where the property already has a suitable natural-gas or LPG supply and the gas line can handle the selected appliance.
When Staying With Heat Pump Is Usually the Stronger Move
If the existing location remains workable, a better replacement heat pump is usually the first option we would compare before paying to add or upgrade gas infrastructure.
Rooftop Solar Is Installed
Solar strengthens the heat-pump pathway because daytime hot-water heating can use electricity the home already generates.
No Gas Supply Exists
Creating a new gas pathway purely for hot water adds infrastructure and fuel dependence that a replacement heat pump avoids.
The Existing Site Is Good
If airflow, drainage, access and noise separation are already suitable, much of the hard site work has already been solved.
The Old Unit Simply Failed
Age or component failure is not proof that the technology is wrong. Compare the old model's history with current replacement options.
You Want Lower Energy Demand
Heat pump remains the efficiency-led pathway; gas is chosen for different practical strengths rather than lower energy demand.
You May Be Eligible for STCs
An eligible replacement heat pump can retain a certificate pathway that conventional gas hot-water systems do not receive.
Supply Only vs Supplied & Installed
Installed Today sells gas and heat-pump systems online for supply-only ordering across supported Australian metro areas, with supplied-and-installed options on selected products in eligible Brisbane and Gold Coast service areas.
Have the Installer Confirm the Conversion First
Changing from heat pump to gas can involve more than swapping the appliance. Confirm gas availability, gas pipe capacity, appliance position, plumbing, electrical requirements and compliance before ordering.
- Confirm natural gas or LPG model.
- Check gas pipe capacity before choosing flow rate or burner input.
- Confirm mounting, flue/terminal and clearances.
- Check who is completing plumbing, gas and any electrical work.
Available on Selected Products & Locations
Where an installed option is shown, work through the product questions and installation scope. Final requirements still depend on the property, existing services, gas type and selected appliance.
- Installation availability is postcode and product dependent.
- Gas upgrades may sit outside a basic replacement scope.
- Instant-gas conversions can require wall mounting and gas-line changes.
- Gas-storage conversions can require new flue and base arrangements.
How to Compare a Heat-Pump-to-Gas Conversion
Start with the reason for changing, then choose between storage and instant gas only after the gas supply and household demand are known.
Identify the Real Problem
Failure, noise, recovery, space and personal preference lead to different solutions.
Check Gas Availability
Confirm natural gas or LPG, pressure, pipe capacity and other connected appliances.
Choose Storage or Instant
Compare tank reserve and recovery against compact continuous-flow delivery.
Compare Against a New Heat Pump
Price the replacement heat pump, any eligible STCs and the complete gas-conversion work before committing.
Heat Pump to Gas Hot Water FAQs
Can I replace a heat pump with gas hot water?
Yes, where a suitable natural-gas or LPG supply is available and the selected gas appliance can be installed compliantly. The conversion scope can include gas pipework, plumbing, mounting, clearances, flue or terminal requirements and electrical work depending on the system.
Should I choose gas storage or instant gas?
Choose between them based on the site and household demand. Gas storage keeps a stored reserve and tank footprint. Instant gas is compact and heats on demand, but the available gas supply and flow rate must support peak simultaneous hot-water use.
Is instant gas better if I want to remove the heat-pump tank?
It can be. A wall-mounted continuous-flow unit can free the ground space used by the heat-pump cylinder, provided there is a compliant appliance position and sufficient gas capacity.
Does a failed heat pump mean gas is more reliable?
Not necessarily. A failure can be related to age, model quality, sizing, controls, installation or service support. If the site still suits a heat pump, compare current replacement models before deciding the technology itself was the problem.
Do I need a gas-line upgrade for instant gas?
Possibly. Continuous-flow appliances can have high instantaneous gas demand. The installer must confirm the meter or LPG supply, regulator, pipe size, pressure and total connected gas load before installation.
Can gas storage use the same position as my heat pump?
Sometimes. The existing tank footprint and water services can be useful, but gas storage has different combustion, flue, clearance and gas-service requirements, so the position still needs to be assessed for the selected model.
Should I switch to gas if I have rooftop solar?
Installed Today would usually compare another heat pump first. A replacement heat pump can use electricity generated by rooftop solar, while gas storage and instant gas continue to rely on purchased gas for normal water heating.
Can a replacement heat pump receive STCs?
Eligible air-source heat-pump models may create Small-scale Technology Certificates when the exact system and completed installation satisfy current scheme requirements. Conventional gas storage and instant gas do not receive this renewable-hot-water STC pathway.
When does gas storage make the most sense?
Gas storage is strongest where a suitable gas supply already exists, the household wants a stored reserve and burner recovery, and the heat-pump location creates a genuine problem such as unmanageable noise or airflow.
When does instant gas make the most sense?
Instant gas is strongest where ground space is valuable, continuous hot-water delivery is important and the property already has a gas supply capable of supporting the selected flow rate.
When would Installed Today recommend staying with heat pump?
If the existing location still suits, rooftop solar is installed, no gas supply exists or the price difference is modest after incentives and conversion work, Installed Today would normally recommend comparing a replacement heat pump first.
Before Switching Back to Gas, Compare All Three Pathways
Gas storage and instant gas can both be legitimate solutions, but they solve different problems. Compare the complete gas conversion against a correctly sized replacement heat pump before giving up the existing heat-pump pathway.
