The gas versus electricity equation has plusses and minuses on both. You are on the right track in thinking that an instant hot water system of either type will produce benefits in terms of long-term savings.

The pros and cons are listed below in no particular order.

Gas:

1. Installation is fairly straightforward and only requires the services of a plumber/gasfitter.
2. Where bottled gas is used:
   • Cylinder replenishment is a tedious process
   • If one is not careful the gas can run out so two cylinders should be used in rotation.
   • Large cylinders are usually rented and represent an additional cost overhead.
   • Cylinder testing is not an issue with rented bottles
   • The cost of delivery and cylinder rental can outweigh the benefits of cheap fuel
   • Maintains a good pressure output for as long as the gas lasts.
3. Where the burner is connected to a Mains Supply the ongoing supply charge can outweigh the benefits of cheap fuel
4. Pilot lights, where used, increase gas consumption to uneconomic levels.
5. Burners using current technology are reasonably efficient and only produce a moderate amount of CO2 and require an exhaust vent.
6. Can only be serviced by a plumber/gasfitter.
7. Parts are generally readily available
8. No preheater is required
9. Hot tap should not be operated when water is not available. [Applies to most appliances]
10. Requires purging to remove air in the pipe after plumbing work to avoid overheating the unit.
11. Can become dangerous if not serviced
12. Can be used standalone or as a backup to an alternative energy system such as wetback fire and solar hot water
13. Consumes about 50% of the energy used by the standard storage cylinder

1. Installation is fairly straightforward and requires the services of an electrician and a plumber.
2. Hot water is available as long as you have electricity
3. There is no direct CO2 component
4. Hot tap must not be operated when water is not available
5. Elements readily available direct from us via courier service
6. Performance is improved if using a preheater.
7. Requires two electrical circuits.
8. Requires purging to remove air in the pipe after plumbing work.
9. Electricity must be turned off while purging to avoid burning-out the heating elements.
10. Before deciding to purchase, verification must be sought from an electrician that the building main supply cable is capable of the high instantaneous electrical current required to heat the water.
11. Can be used standalone or as a backup to an alternative energy system such as wetback fire and solar hot water
12. Consumes about 50% of the energy used by the standard storage cylinder