Hot Water System Installation — Safe Work Method Statement
Safe Work Method Statement for the installation and commissioning of electric, gas, heat pump, and solar hot water systems including plumbing connections, electrical terminations, and TPR valve installation.
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Hot water system (HWS) installation in Australia spans multiple licensed trades and regulatory frameworks. Plumbing connections must be made by a licensed plumber in compliance with AS/NZS 3500.4 (Heated water services). Electrical connections for electric HWS and heat pump systems must be made by a licensed electrician under state electrical safety legislation. Gas connections for gas HWS must be made by a licensed gasfitter in compliance with AS/NZS 5601. Many hot water installations involve all three trades, and the SWMS must address the coordination and sequencing of each.
The temperature and pressure relief (TPR) valve is the most critical safety component of any hot water system. The TPR valve must comply with AS 1357 and be installed and tested in accordance with AS/NZS 3500.4. Its discharge pipe must be routed to a safe discharge point that will not cause burns if the valve activates. A non-compliant or incorrectly installed TPR valve can result in catastrophic tank explosion — a failure mode that has caused fatalities and building damage. The SWMS must specifically address correct TPR valve selection, installation torque, discharge pipe routing, and commissioning test.
For solar hot water systems, roof-mounted collector panels involve working at height and present fall risk exceeding 2 metres, making this component HRCW under Schedule 3 of the model WHS Regulations. A specific fall prevention plan addressing roof access, anchor points, and panel handling in wind must be incorporated into the SWMS for any roof-mounted solar HWS installation.
Heat pump HWS units installed outdoors or in plant rooms may require refrigerant pipe connections that must be performed by a licensed refrigeration mechanic holding an Australian Refrigeration Council (ARC) Refrigerant Handling Licence under the Ozone Protection and Synthetic Greenhouse Gas Management Act 1989 (Cth). Handling refrigerants without an ARC licence is a federal offence.
Customise this template with the HWS type and model, the TPR valve specification and discharge arrangement, the trade licence numbers for each discipline, and the roof access method for solar systems. This SWMS applies in all Australian jurisdictions.
Personal Protective Equipment
High Risk Construction Work Types
- •Work involving risk of a person falling more than 2 metres
- •Work near energised electrical installations
Risk Assessment
1.Site Preparation and Isolation of Existing Services
| Hazard / Risk | Initial Risk | Control Measures | Residual Risk | Responsibility |
|---|---|---|---|---|
| Electrocution during replacement of existing electric hot water system | Catastrophic | All electrical isolation must be performed by a licensed electrician before the plumber commences any connection work. Isolate circuit at switchboard, apply LOTO, and verify isolation with an approved voltage tester. Retain lock and tag until electrical connections are complete and verified. Plumber must confirm isolation status with the electrician before touching any electrical components. Never assume isolation without personal verification. | Low | Licensed Electrician / Licensed Plumber |
2.Manual Handling of Hot Water Units
| Hazard / Risk | Initial Risk | Control Measures | Residual Risk | Responsibility |
|---|---|---|---|---|
| Musculoskeletal injury from lifting and positioning heavy hot water cylinders | High | Hot water cylinders above 50 kg must be moved using a sack truck, pallet jack, or crane lift — not manually lifted by workers. Where a cylinder must be lifted manually to a final installation position (e.g., on a platform bracket), use a minimum two-person lift with a third person stabilising. Workers must maintain neutral spine, bend at knees, and keep load close to body. Plan material delivery to minimise carry distance. If installation is on a roof, use a crane or mechanical hoist — never carry a heavy cylinder up a ladder. | Low | All Workers / Site Supervisor |
3.Roof Mounting of Solar or Heat Pump Units
| Hazard / Risk | Initial Risk | Control Measures | Residual Risk | Responsibility |
|---|---|---|---|---|
| Falls from roof during installation of roof-mounted units | Catastrophic | Install a roof anchor to AS/NZS 1891.4 before any worker accesses the roof. Workers wear full-body harness and shock-absorbing lanyard connected to the roof anchor at all times on roof. For roofs with a pitch above 26 degrees or greater than 3 m above the gutter line, provide a roof bracket ladder system and running line. Tools and components must be hoisted using a rope or crane — not carried while climbing. Conduct a roof edge fall risk assessment before commencing and document in a pre-task risk assessment. | Moderate | Licensed Plumber / Site Supervisor |
4.Plumbing Connections
| Hazard / Risk | Initial Risk | Control Measures | Residual Risk | Responsibility |
|---|---|---|---|---|
| Scalding from hot water released when removing old system before drainage is complete | High | Before disconnecting any hot water pipework, shut off the cold water supply to the cylinder and allow the system to drain through the drain valve to a safe disposal point. Open the nearest hot tap to vent pressure and confirm zero residual pressure. Allow cylinder to cool to below 40°C before disconnecting — estimated cool-down time for a 250 L cylinder is 3–4 hours after isolation. If time does not permit cooling, wear heat-resistant gloves and face shield and loosen connections slowly, standing clear of the direction of any residual water release. | Low | Licensed Plumber |
5.Commissioning and TPR Valve Testing
| Hazard / Risk | Initial Risk | Control Measures | Residual Risk | Responsibility |
|---|---|---|---|---|
| Scalding discharge from temperature-pressure relief (TPR) valve during testing | High | Connect the TPR valve discharge pipe to a safe, low-level drain before testing — never leave the discharge termination pointing upward or toward workers. During manual TPR lift test, direct all workers to stand clear of the discharge pipe termination. Lift test must be conducted with the system at maximum operating temperature and pressure. Confirm the valve reseats cleanly after lifting. If the valve fails to reseat or continues to drip, replace it before the system is commissioned and handed to the client. | Low | Licensed Plumber |
Relevant Codes of Practice
Worker Acknowledgement
By signing below, I confirm that I have read, understood and agree to comply with this Safe Work Method Statement.