A household hot water heating system includes a cold-water inlet, a water heater or heat source, operating controls, safety and pressure-control valves, and insulated hot-water pipes supplying taps and appliances. A storage tank is not always included: continuous-flow systems heat water on demand.
Core components
- Cold-water inlet: Supplies water to the heater, often through isolation, non-return or pressure-control fittings.
- Water heater or heat source: Uses an energy source such as electricity, gas, ambient air or solar energy. The heating equipment may be an element, burner and heat exchanger, heat-pump circuit or solar collector.
- Operating controls: Storage systems commonly use a thermostat. Continuous-flow units use flow sensors and electronic controls to activate heating when water is drawn.
- Hot-water pipework: Carries heated water to taps, showers and connected appliances. Insulation reduces heat loss.
- Safety and pressure controls: Protect the heater and pipework from unsafe temperature or pressure. The required fittings vary by system design.
A temperature-and-pressure relief (TPR) valve releases water if temperature or pressure becomes excessive inside a storage water heater. A tempering valve instead mixes hot and cold water to limit the temperature delivered to designated outlets.
Do not cap, block or adjust safety-valve discharge pipes or temperature controls. If a valve needs attention, contact a licensed plumber.
Components by system type
| System type | Typical system-specific components |
|---|---|
| Storage | Insulated tank, heating element or gas burner, thermostat and TPR valve. Many tanks also have a sacrificial anode for corrosion protection. |
| Continuous flow | No bulk storage tank; typically includes a flow sensor, heat exchanger, gas burner or electric elements, and electronic controls. |
| Heat pump | Storage tank, evaporator, compressor, fan and condenser, arranged as an integrated or split system. |
| Solar | Solar collectors, storage tank, connecting pipework, controller and usually a gas or electric booster. Some systems also have a circulation pump or heat exchanger. |
Storage, heat-pump and most solar systems include a tank; a typical continuous-flow system does not. Under AS/NZS 3500.4 (the national plumbing standard regulating hot water system safety, relief drainage, and scald protection), every component must be correctly matched to your property’s water supply pressure. For consultative guidance on selecting the right unit, ask our Sydney installation team to assess your property and hot-water demand. Fixed Today has served Sydney homeowners since 2011 with upfront fixed pricing and thorough task breakdowns. Sharing details about your existing fuel source, household size, and available outdoor or indoor space helps our team bring the right system options for your home.