Replace gas boiler with electric

Image of HydroAir hydronic heat pumps
HydroAir air-to-water hydronic heat pumps

Key Points

Existing Homes

Replace your gas boiler with an electric heat pump for these benefits:

  • Savings on your energy bills
  • Use with your solar power
  • Added value to your home
  • Cleaner and safer
  • Helps reduce greenhouse gas emissions
  • Consistent with government policies
  • Helps to avoid the gas supply shortfall causing further price increases
  • Common questions

Capital Costs

Throughout Australia, there are over 5 million existing homes currently using gas appliances with nearly half located in Victoria. Clearly, there is a big task ahead to convert these homes to electric.

Manage the capital costs by:

  • Staged implementation plan
  • Replacing your gas boiler and other gas appliances with electric as they wear out
  • Investigating your eligibility for government incentives and green loans
Graph showing gas supply and demand projections in Victoria
Victorian gas supply and demand projections Reference: Victorian Gas Market Demand Review, Northmore Gordon, March 2020
Hydrosol image of roof mounted air-to-air and air-to-water hydronic heat pumps
Air-to-air and air-to-water (hydronic) electric heat pumps

New Homes

For new homes, all gas heating, cooling, hot water, and cooking appliances must now be electric because the Victorian government banned gas connections for new homes since January 2024.

For electric heating and cooling, air-to-air (‘aircon’) and air-to-water (hydronic) heat pumps are the most energy efficient.

Also consider:

In addition, electric vehicles are trending upwards as internal combustion engines are phased out. Give this some thought too, as it will create another large power demand if you have or are planning for an electric vehicle.

Consider all major electric appliances if you are rewiring your house.

Energy Cost Savings

Studies have found significant energy cost savings from switching from gas to electric appliances, up to $14,000 over 10 years in Melbourne for example. Homes in other cities will make significant savings too.

Reference: Grattan Institute

Use of your own solar power will give you further savings. Some energy efficient homes can generate as much or more power than they consume.

Graph showing gas to electric appliance operating cost savings
Reference Grattan Institute, gas to electric appliance operating cost savings
Hydrosol image of hydronic radiator panel
Hydronic Radiator Panel

Gas to Electric Power Considerations

Heating Demand

Your heating boiler accounts for more than one third of your annual household energy demand. For your gas demand to be switched to electric, check that your power supply and switchboard have sufficient capacity.

Existing Radiator Panels & Underfloor Heating

As with your gas boiler, an electric hydronic heat pump transfers heat into your home by circulating hot water through radiator panels, underfloor heating coils or fan-coil convectors. It is usually fine to use your existing hydronic heating systems because:

  • High temperature hydronic heat pumps can heat water to the same temperature as your gas boiler if necessary
  • Thermal improvements to your home will reduce your heating load making it easier to replace your gas boiler with an electric heat pump
  • You can also use room zoning to reduce your heating load
  • You can adjust your run times, set temperatures or heating programs slightly to reduce your heating load

Seek advice to make sure your electric hydronic heat pump will satisfy your winter heating load using your existing hydronic systems.

Power Supply

In Australia, homes typically have 1-phase power of 230-240 volts with standard capacity ranging from 40 amps to 80 amps. If you are at the lower end of this range, you will probably need to upgrade your power supply. If you have or planning for an electric vehicle, then an upgrade is most likely.

Ensure your power supply will support your increased power load. Check your power switchboard and make sure it has a spare slot for your hydronic heat pump switch. If you are upgrading your gas cooktop or oven to electric, you will need dedicated switches for these appliances also. You may need to upgrade your switchboard.

If you are adding an electrical vehicle to your power demand, then an upgrade is most likely.

Consider whether it makes sense to upgrade to 3-phase power. This would give you higher capacity and distribute power more evenly and efficiently compared to 1-phase. It reduces the strain on individual circuits.

Consider your power supply needs before installing new solar power. Also, factor in potential delays for installation and plan for it. 

Consult a qualified electrician to provide an assessment of your electrical system and the upgrade required. Your electrician will ensure compliance with electrical codes and regulations. Hydrosol can make a referral for you in Melbourne: contact us

Image of a solar power inverter and switchboard
Solar power inverter and switchboard
Hydrosol image of Stiebel Eltron buffer tanks, 100 and 1500 litre buffer tanks, larger tanks can be used as a thermal battery.
Buffer tanks range from 100 to1500 litres

Batteries

It is better to use power than store it. Time your discretionary high-demand appliances to run during the day with your solar power. Run your higher powered heating and cooling equipment during the day as far as possible.

Consider the economics of a solar battery against the marginal power demand of your non-discretionary appliances like refrigerators and cooking appliances. Will the cost of the battery justify this demand?

Consider a larger buffer tank with your hydronic heat pump if you have space.  Water is an excellent store of thermal energy. It will give you a thermal battery.

For lightweight homes (eg weatherboard on stumps), this will provide additional thermal mass.