HOT WATER COMPLIANCE

Safe trays for hot water units: when you need one

Put a hot water unit somewhere a leak would do damage, like a roof space or above a living area, and it needs a safe tray underneath to catch that water and take it away. Here is when one is required and the rules it follows.

What a safe tray is for

A safe tray sits under the unit and channels any leak or relief discharge to a drain instead of into the ceiling or the floor below. It is a damage-control measure, and it is mandatory wherever a failure would not be obvious or would cause harm.

When it is required

A safe tray is generally required where the unit is installed in a roof space, in a concealed location, or above a habitable area. If the unit sits on the ground outside where a leak runs away harmlessly, a tray is usually not needed. The test is whether a leak would be caught early or do quiet damage.

The rules that matter

• The tray must be the right size for the unit, with a turn-up at the edges so water cannot run over the side.
• It needs a drain of the correct size, with a continuous fall, running to a safe and visible discharge point.
• The unit sits clear of the tray edge so the whole footprint is captured.
• The tray and drain are watertight.

What to photograph

• The unit sitting in the tray, showing the turn-up and clearances.
• The drain connection and its fall.
• The discharge point, showing it is visible and safe.

Elemetric captures this set as part of the job, so a concealed install still has a clear record behind it.

Common questions

When is a safe tray required?

Generally where a hot water unit is in a roof space, a concealed location, or above a habitable area, so a leak is taken away rather than soaking into the building.

Does a unit on the ground outside need a tray?

Usually not, if a leak would run away harmlessly. The test is whether a failure would be caught early or cause quiet damage.

General information for licensed tradespeople, not legal or regulatory advice. The licensed plumber remains solely responsible for compliance. Refer to the current AS/NZS 3500 standards and the Building and Plumbing Commission (formerly the VBA) for authoritative requirements.