Installation, Commissioning, and Customer Handover
This domain tests whether an installation is safe, code-compliant, and working before you leave. Questions often describe a site condition and ask what must be verified or corrected.
Before installation
- Confirm the model, dimensions, clearances, and utility requirements against the manufacturer's instructions. The instructions and the adopted code govern; where they differ, the stricter requirement applies.
- Electrical: dedicated circuit, correct voltage and amperage, receptacle type, GFCI/AFCI where required, and cord length. Do not use an extension cord as a permanent supply.
- Gas: pipe size, shutoff valve, connector, sediment trap, and venting. Gas connection and testing are restricted to licensed gas fitters.
- Water: supply pressure, shutoff, backflow protection, drain capacity, and a high loop or air gap for dishwashers and washing machines.
- Venting: dryer transition duct must be smooth, sealed, and within the length and elbow limits; vinyl or foil flex duct is a fire and lint hazard.
- Structural: anti-tip brackets for ranges, leveling, floor protection, and secure mounting.
Commissioning checks
- Verify polarity and ground at the receptacle; check the appliance frame for stray voltage.
- Leak-test water and gas connections; run a full cycle and observe.
- Measure current draw, temperatures, pressures, and airflow against specification.
- Confirm controls, safeties, and shutoffs operate; check for vibration and unusual noise.
Handover
- Demonstrate operation, filters, cleaning, and shutoffs.
- Provide manuals, warranty information, and your contact details.
- Record readings, model/serial numbers, and any limitations.
Worked example
You install a dishwasher. The drain hose is looped high under the counter to prevent backflow, the supply is connected with a new braided hose and shutoff, and the receptacle is GFCI-protected and accessible. You level the unit, run a cycle, check for leaks at the supply, drain, and pump, and confirm the drain does not siphon. You record the model and serial number and show the customer the filter and air gap.
Traps
- Using flexible foil dryer duct.
- Over-tightening a gas connector and damaging the seal.
- Skipping polarity and ground checks because the appliance "runs."
- Leaving without a cycle test and leak check.