At least every twelve months, by a plumber holding the TMV endorsement, unless a documented risk assessment sets a shorter interval. NSW Health requires six-monthly testing in hospitals, and aged care, childcare and disability accommodation operators commonly adopt the same interval. The test confirms the outlet temperature, the fail-safe shut-off when cold water is lost, and the valve's response, and it services the strainers and seals. A monthly outlet temperature check with a calibrated thermometer is recommended practice between visits.
The intervals
| Interval | What happens | Who |
|---|---|---|
| Monthly (recommended practice) | Outlet temperature at each TMV outlet with a calibrated thermometer; anything above 50 degrees at a TMV outlet is investigated the same day. | Owner or staff |
| At least every 12 months | Field test and service under AS 4032.3: outlet temperature, fail-safe shut-off, response to cold supply loss, strainers and seals; a documented risk assessment can shorten the interval. | Plumber with the TMV endorsement |
| Six-monthly (hospitals) | NSW Health requires six-monthly testing in hospitals; aged care, childcare and disability settings commonly adopt it. | Plumber with the TMV endorsement |
| About five years | Replacement of the thermostat and seals, or of the valve, per the manufacturer. | Plumber with the TMV endorsement |
Who does it and what to keep
Only a plumber holding the TMV endorsement (a short accredited course on top of the licence) may test and service the valves. The record is a test and service report for each valve: its location and outlets, the temperature readings before and after, the fail-safe result, the parts replaced and the next test date, kept with the building's water safety records. In aged care and health settings the report is part of the water safety plan the accreditor reads.
The rule behind the interval
AS 4032.3 Water supply: Valves for the control of heated water supply temperatures, Part 3: Requirements for field-testing, maintenance or replacement of thermostatic mixing valves, tempering valves and end-of-line temperature-actuated devices, sets the twelve-month maximum and the test content. AS/NZS 3500.4 sets the 50 degree limit at outlets in the buildings that must have the valves (and 45 degrees in some care settings). NSW Health's water safety guidance sets the six-monthly hospital interval.
Common questions
Is a tempering valve the same as a TMV?
No. A tempering valve is a simpler, cheaper device with a wider temperature band, used where the 50 degree limit applies but the occupants are not vulnerable. A TMV holds temperature more tightly and shuts off on loss of cold water, which is why care settings require it. Both are field-tested under AS 4032.3.
Who can test a TMV?
A licensed plumber who holds the TMV endorsement. The monthly temperature check between visits can be done by staff with a calibrated thermometer.
Put it in the register
An interval only holds when the asset is listed with its tasks, its contractor and where the record lives. Standara's library carries this asset with the tasks above attached, so adding it to a site's register produces the year's schedule, the monthly to-do list and the completion record the auditor or insurer asks for. The fuller picture, with the neighbouring assets and the rule behind each interval, is in the Water systems testing schedule.
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