Gas Storage to Heat Pump Hot Water
Gas Storage to Heat Pump Hot Water: Is It Worth Upgrading?
What happens to the gas connection, what electrical work is needed — and whether changing to heat pump makes sense for your home.
Replacing gas storage hot water with a heat pump changes more than the heater itself. The new system uses electricity instead of gas, so the conversion can involve gas isolation, a suitable electrical supply, drainage, positioning and a different approach to household hot-water recovery. This guide explains the complete upgrade.
Does Heat Pump Suit My Gas Home?
Answer three quick questions for a preliminary pathway. The exact system and installation still need to suit your property.
1 What gas storage system do you have?
2 Where is the existing gas tank?
3 What matters most?
Guide only. Gas isolation, electrical requirements, airflow, clearances, drainage, noise and household hot-water demand need to be checked for the selected system.
Can You Replace Gas Storage Hot Water With a Heat Pump?
Yes. A gas storage system can be replaced with a heat pump even though the two systems use different energy sources. The existing hot and cold water pipework may often be useful, but the gas connection must be dealt with correctly and the new heat pump needs a suitable electrical supply, airflow, drainage and installation position.
Gas Connection
The old gas hot-water connection needs to be safely isolated and appropriately capped or altered as part of removing the gas appliance.
Electrical Supply
The replacement heat pump requires electricity for its compressor, fan and controls. The electrical requirements depend on the exact model.
Existing Plumbing
Existing hot and cold water services can often form part of the new installation, although valves and pipework may require alteration.
Heat Pump Location
Airflow, condensate drainage, noise, service access and manufacturer clearances need to suit the new appliance.
Why Change From Gas Storage to Heat Pump Hot Water?
Gas storage heats a tank by burning natural gas or LPG and can provide strong recovery. A heat pump takes a different approach, using electricity to transfer heat from the surrounding air into stored water. The change can make particular sense for homes moving toward electric appliances or wanting to use rooftop solar for water heating.
Reduce Gas Dependence
Changing the hot-water system from gas to heat pump removes gas from water heating. If hot water is the property's only remaining gas appliance, the conversion may also form part of a wider move away from gas.
Use Rooftop Solar
Many heat pumps can be scheduled to operate during daylight hours, creating an opportunity to use household solar generation to heat stored water.
Eligible STC Incentives
Eligible listed air-source heat pumps can create Small-scale Technology Certificates when the exact model and completed installation meet current scheme requirements.
Gas Storage vs Heat Pump Hot Water: Current JR Starting Prices
Staying with gas storage can be one of the simpler replacement pathways for an existing gas-storage home. Moving to heat pump involves a technology and energy-source change, so compare the full installed conversion rather than the product price alone.
Often the more straightforward replacement pathway where suitable gas infrastructure is already in place.
Current JR advertised starting price. Final cost depends on the selected system, gas type and installation scope.
Changes the home from gas-powered water heating to an efficient electrically powered heat-pump system.
Current JR advertised starting price. STC eligibility depends on the exact system and completed installation.
Gas Storage vs Heat Pump Hot Water
| Consideration | Gas Storage | Heat Pump |
|---|---|---|
| Energy source | Natural gas or LPG | Electricity |
| Existing gas connection | Remains in use | Hot-water gas connection is no longer required |
| Electrical requirement | Depends on gas heater design | Electrical supply required for heat pump operation |
| Rooftop solar use | Does not use solar-PV electricity to heat water | Can often be scheduled around solar generation |
| STC eligibility | Not eligible simply because it is a new gas system | Eligible listed heat pumps may qualify |
| Recovery | Gas storage can provide fast recovery | Recovery varies significantly by heat-pump model |
| Noise | No heat-pump compressor or fan | Compressor and fan operate during heating |
| Typical upgrade reason | Simple replacement while remaining on gas | Efficiency, solar use and reducing gas dependence |
What Actually Changes During a Gas-to-Heat-Pump Conversion?
The plumbing may look familiar, but the services powering the new heater are completely different. A proper conversion considers the gas, electrical, plumbing and heat-pump requirements together.
Gas Is Isolated
The existing gas hot-water appliance is disconnected and its gas connection is appropriately dealt with for the finished installation.
Electrical Supply Is Added or Checked
The selected heat pump needs the correct electrical connection and protection for its particular requirements.
Water Services Are Adapted
Existing hot and cold pipework may be reused where suitable, with valves and connections changed to suit the new system.
The Position Is Rechecked
A location suitable for gas storage is not automatically suitable for every heat pump. Airflow, clearances and noise now matter.
Drainage Is Considered
Heat pumps can produce condensate in addition to the normal drainage requirements associated with stored hot water.
Heat Pump Is Commissioned
The system is filled, tested and configured before being placed into normal service.
What Happens to the Gas Connection After the Heat Pump Is Installed?
Changing the hot-water system to heat pump does not automatically mean every gas service at the property disappears. What happens next depends on whether the home still uses gas for cooking, heating or other appliances.
Keep the Property Gas Supply
If the property still has a gas cooktop, heater, fireplace or another gas appliance, the main gas supply may continue to be required.
The old hot-water branch is dealt with appropriately while the remaining gas appliances continue to use the property's gas service.
Opportunity to Move Further Away From Gas
If hot water is the only remaining gas appliance, replacing it with a heat pump may allow the household to consider whether it still needs an active gas service at all.
Any change to the broader property gas supply should be considered separately from simply disconnecting the old hot-water appliance.
What Electrical Work Is Needed When Replacing Gas With a Heat Pump?
This is one of the biggest differences from a gas-to-gas replacement. A heat pump needs electricity to operate its compressor, fan and controls, so the electrical installation needs to suit the exact model being installed.
Power at the Location
The fact that gas storage currently occupies the space does not mean suitable electrical power is already available for the replacement heat pump.
Exact Model Requirements
Different heat pumps have different connection, protection and electrical requirements. The product should be selected before the final electrical scope is confirmed.
Switchboard & Circuit
The existing electrical installation needs to support the required connection. Additional electrical work can therefore affect the final conversion price.
Can the Heat Pump Go Where the Gas Storage Tank Is Now?
Often it can, particularly where the existing gas storage tank is outside at ground level with good access. However, the location needs to be reassessed for the heat pump rather than assumed suitable simply because a gas tank already sits there.
Airflow
The heat pump needs the surrounding air volume and clearances required by the selected model.
Noise
Proximity to bedrooms, neighbouring homes and enclosed courtyards matters because heat pumps contain a compressor and fan.
Electrical Access
A practical pathway for the required electrical supply can influence whether the old gas position remains the best location.
Drainage
A suitable pathway is needed for both required hot-water discharge and heat-pump condensate.
Base & Support
The new heat pump needs suitable stable support for the selected system and installation conditions.
Service Access
Enough room should remain for installation, servicing and future repairs or replacement.
Have Rooftop Solar? This Is One of the Biggest Changes From Gas
Gas storage cannot use rooftop solar PV to heat the water. A heat pump can. Where the system and household usage suit it, daytime operation can shift a meaningful part of water heating into solar-production hours.
Use Solar Generation
A heat pump can consume household solar electricity while operating instead of relying entirely on imported electricity.
Store Energy as Hot Water
The tank stores heated water for later use, allowing daytime solar generation to contribute to hot water needed later in the day.
Schedule Around the Home
Timers, controls, recovery requirements and normal household demand should all be considered when setting the operating schedule.
Can You Get STCs When Replacing Gas Storage With a Heat Pump?
Potentially. The old heater being gas does not prevent an eligible new heat pump from qualifying. STC eligibility is determined by the new heat-pump model, its eligible configuration and the completed installation under the current scheme rules.
Choose an Eligible Heat Pump
The exact air-source heat pump needs to be listed as eligible for the relevant installation period.
Install the Correct Configuration
The installed system needs to match its eligible configuration and applicable installation requirements.
Complete the STC Pathway
The completed installation and required evidence support the final STC claim and assignment process.
When Staying With Gas Storage Can Still Make Sense
Changing technology is not automatically the best pathway for every property. An existing gas-storage home can have circumstances where another gas-storage system remains a practical replacement.
Simple Replacement Is the Priority
Where the existing gas setup is compliant and suitable, replacing gas storage with gas storage can involve fewer changes to the property's services.
Fast Recovery Matters
Gas storage systems can provide strong recovery, so household demand and recovery requirements should be considered when changing technologies.
Heat-Pump Location Is Poor
A property without an appropriate location for airflow, noise, drainage or electrical access may make a heat-pump conversion less straightforward.
How a Gas-Storage-to-Heat-Pump Replacement Works
Choose the Heat Pump
Compare capacity, recovery, noise, controls, electrical requirements, warranty and final installed price.
Confirm the Conversion Scope
Check gas, electrical supply, plumbing, installation position, access, base and drainage.
Disconnect the Gas Heater
The existing gas-storage system is isolated, disconnected and removed, with the old gas connection dealt with appropriately.
Install the Heat Pump
The new system, plumbing, valves, drainage and required electrical work are completed.
Commission & Test
The heat pump is filled, tested and configured for normal operation.
Complete STC Requirements
Where eligible, the required STC documentation and assignment process are completed for the installed system.
Gas Storage to Heat Pump Hot Water FAQs
Can I replace a gas storage hot-water system with a heat pump?
Yes. Gas storage can be replaced with a heat pump, but the conversion changes the energy source from gas to electricity. The gas connection, electrical supply, plumbing, installation position and drainage all need to be considered.
Is it worth changing from gas storage to heat pump hot water?
It can be attractive for households wanting to reduce gas use, improve hot-water energy efficiency or use rooftop solar for water heating. The final decision should compare conversion cost, household demand, recovery, installation position and expected long-term ownership.
What happens to the old gas connection?
The gas connection serving the old hot-water appliance needs to be safely isolated and appropriately dealt with as part of the finished installation. The property's broader gas supply may remain if other gas appliances are still used.
Can I disconnect gas completely after installing a heat pump?
If the gas hot-water system is the property's last gas appliance, changing to heat pump may create an opportunity to consider whether the property still needs an active gas supply. If gas cooking, heating or other appliances remain, the gas service may still be required.
Can I replace LPG gas storage with a heat pump?
Yes. An LPG storage water heater can be replaced with a heat pump. The LPG hot-water connection is removed from use while the new system requires a suitable electrical supply and heat-pump installation position.
Does a gas-to-heat-pump conversion need an electrician?
Electrical work depends on the selected heat pump and the existing property infrastructure. Because the replacement appliance is electrically powered, its required electrical connection and protection need to be provided correctly.
Can the heat pump go where my gas storage tank is now?
Often, particularly where the gas storage system is already outside at ground level. The position still needs to meet the heat pump's airflow, clearance, drainage, electrical-access, service-access and noise requirements.
Can I use the existing hot and cold water pipes?
Existing hot and cold water pipework can often form part of the new installation where suitable, although valves, connection points, insulation or sections of pipework may need to be altered.
Is heat pump hot water better if I have rooftop solar?
Rooftop solar can make the change particularly interesting because a heat pump uses electricity rather than gas. Many systems can be scheduled to operate during solar-production hours where household demand and system controls allow.
Can I get STCs when replacing gas hot water with a heat pump?
An eligible new air-source heat pump may qualify for STCs when the exact model and completed installation meet current scheme requirements. The fact that the previous heater used gas does not itself prevent the new eligible heat pump from qualifying.
Does every heat pump get the same STC value?
No. STC entitlement can vary according to the exact listed model, installation date and geographic zone.
Will a heat pump recover hot water as fast as gas storage?
Recovery performance varies by heat-pump model and should not be judged by tank capacity alone. Gas storage can provide strong gas-fired recovery, so a replacement heat pump should be selected around household demand, usable storage and recovery performance.
Ready to Compare Gas Storage Against Heat Pump?
Compare JR's current heat-pump range by installed price, capacity, recovery, controls, electrical requirements and suitability. If changing technology does not suit the property, compare current gas-storage systems or return to the complete hot-water range.