Hot Water System Types

Electric hot water systems

These are being phased out for more environmentally friendly hot water systems. With the current regulations you may not be eligible to install one of these water heaters if it will cost you nothing to have natural gas supplied to your house. These systems also create the most greenhouse emissions.

Gas hot water systems

You may need a gasfitter to run a gas line. Gas water heaters can either heat the stored water (gas storage hot water systems) or heat the flowing water instantly (gas instantaneous hot water systems – now termed gas continous flow ).

A gas water heater is cheaper to run on natural gas compared to using LPG cylinders. The good thing is there is always hot water available in normal operation.

The storage water heaters allow higher mains pressure through your taps. This is good when you need larger volumes of hot water simultaneously through multiple taps or when your water pressure to your house is too low.

The instantaneous water heaters only heat the water when the tap is flowing, therefore only up to three taps can be used at once. However this system typically uses less gas than the storage type system. Temperature controllers or touch pads mounted on the inside walls can further reduce your gas consumption. This is because the unit will now produce hot water at the temperature you need at the taps, compared to having the temperature too high then mixing cold water to cool it down which uses more gas.

Heat Pump hot water systems

Heat Pump water heaters use a heat pump module that absorbs the heat in the air and transfers it into the stored water. The heat pump module creates some noise when heating, similar to the outside unit on a split system air conditioner.

Therefore carefully consider it’s location when nearby bedrooms and windows are present to reduce noise concerns. Naturally they work less hard when located on hotter side of your house.

Solar hot water systems

Solar water heaters can have both the collectors and storage tank mounted on the roof (Close Coupled unit) or just the collectors on the roof and the tank on the ground (Split System unit).
There are also anti-freeze models for both types if you’re in a frost prone area. They can be gas or electric boosted when not hot enough.

It is best to have the collectors on a north facing roof area for the best solar contribution. They are normally cheaper to run but may need boosting on cloudy days which adds to running costs.