Electrical safety
Never restrict an open-outlet water heater
Never restrict the outlet of an open-outlet storage water heater. Ask a qualified person to confirm the manufacturer's specified fittings.
Last reviewed: 2026-09-20
Why it matters
Blocking an open-outlet storage water heater can allow dangerous pressure to build inside its tank.
Wrong action
Adding a shut-off valve to the outlet while changing the shower fitting.
Correct action
Never restrict the outlet of an open-outlet storage water heater.
What to do
- Identify the heater type before anyone changes its shower or outlet.
- Never restrict the outlet of an open-outlet storage water heater.
- Ask a qualified person to confirm the manufacturer's specified fittings.
If something happens
For serious injury, unconsciousness or difficulty breathing, keep yourself safe, call 999 and follow the operator.
Sources and review
- Electrical and Mechanical Services Department — EMSD: Household Electrical Safety Handbook sections 2.3.1-2.3.7
Last reviewed: 2026-09-20
This page provides general home-safety information and does not replace medical, legal, electrical, or other professional advice.