These can be installed inside your house, but need a flue to discharge combustion products. A high-efficiency gas hot-water cylinder fitted outside the house may be a better bet. You save interior space and you don't need a flue. They are more efficient than internal ones, but this can be offset by the heat loss from the cylinder operating in a colder environment and the higher purchase cost.
Gas and electricity prices are now fairly close, but there are other costs. There's a daily service charge to be paid, summer as well as winter, on top of the line or supply charge you already pay for electricity. There will also be a connection fee. Gas water heaters cost more than electric ones and their installation costs are higher. Also they aren't as efficient at converting energy into hot water, and have higher standing losses too.
All this means using gas to heat your water is not economic for many households. But, if you already have a gas connection, and especially if you have a larger family, by all means use it.
The main attraction: lots of hot water for large families (gas cylinders reheat their water more quickly than electric ones).
The main drawbacks: gas hot-water cylinders have lower efficiency and higher heat losses than equivalent electric cylinders, and can't have insulation wraps added.
If you want to use gas, and don't have a street connection, a cylinder-swap LPG system could work well.
- In most cases a budget price would be between $2800 - $3200 incl GST