Answers to Common Questions and Some Troubleshooting Tips to Help You Better Understand Hot Water Systems
What kind of hot water system should I use?
Choose one based on the available energy source in your property, whether electricity, gas or solar. The availability of fuel can help reduce operating costs. For example, it is more affordable to operate a gas hot water system when you can connect it to an existing natural gas line.
What are the types of hot water systems available?
- Gas Hot Water Systems
- Electric Hot Water System
- Solar Hot Water System
- Heat Pump
What's the difference between storage and continuous flow hot water system?
Storage hot water systems use a tank to store hot water, while a continuous flow system only heats water when needed. Water is heated as it passes through heating equipment.
How do I choose a storage hot water system in the right size?
Consider the size of your household and the amount of water they need. The more people using hot water the larger the storage tank.
Size of electric storage hot water systems based on demand
High demand for hot water
- 5+ people = 450L
- 3-4 people = 284L
- 2-3 people = 182L
Regular demand for hot water
- 5+ people = 284L
- 3-4 people = 182L
- 2-3 people = 182L
- 1-2 people = 182L
Size of gas storage hot water systems based on demand
High demand for hot water
- 5+ people = 227-228L
- 3-4 people = 189-227L
- 2-3 people = 189L
Regular demand for hot water
- 5+ people = 189L
- 3-4 people = 151L
- 2-3 people = 151L
- 1-2 people = 151L
How do I choose a continuous flow or instantaneous system with the right size?
Count the number of hot water outlets and their flow rate in litres per minute. About 22–24 L/min of flow rate is sufficient for a two-bathroom house.
How do I choose a solar water heater with the right size?
Count the number of people who will need hot water. The more people in a household, the more solar collectors are needed and the larger the storage tank.
What are my energy-efficient options to replace an electric hot water system?
- Heat-pump hot water system
- Solar hot water system
- High-efficiency natural gas/LPG storage or continuous flow hot water system
What government incentives are available for hot water systems?
Only solar water heaters qualify for a tax credit. You can claim:
- 30% of the cost, including installation costs, for 2017-2019 tax years
- 26% for the 2020 tax year
- 22% for the 2021 tax year
Troubleshooting Hot Water Systems
Why doesn’t the pilot light in my gas water heater not working or keeps going out?
The pilot light doesn’t work due to several reasons—insufficient hot water, running out of hot water, or wrong-sized storage tank.
The pilot light might flicker or go out after being relit due to a faulty thermocouple, faulty thermostat, or blocked pilot tube.
Why is my continuous gas hot water service, producing lukewarm water?
This may be due to a faulty thermostat or wear and tear in the diaphragm in the water section.
If you have a Bosch and Rheem instantaneous hot water system, have it checked by a gas fitter as this is a common issue with this type of equipment.
Why is my electric hot water system not working?
This can happen due to faulty wiring, element, thermostat, tempering valve, or the time clock within the water heater. It can also be caused by a short circuit at the service or that the terminal block burned out.
