TMV Testing & Servicing on the Central Coast
Donza Plumbing tests, services, installs and replaces thermostatic mixing valves (TMVs) across the Central Coast, Lake Macquarie and Newcastle, from a base in Mannering Park. A TMV holds the water at the tap warm enough to wash with and not hot enough to scald. After a test you get a written report with the temperature set and the next service date.
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TMV work we do
- TMV testing & servicing
- Commissioning a new valve
- New TMV installation
- Repair & replacement, then retest
- Written report for the owner
- NDIS & accessible bathrooms
- Commercial outlets
- Backflow tested on the same visit
TMVs are a regular part of our hot water and compliance work, including NDIS and commercial outlets. Backflow devices are covered on the backflow prevention and testing page, and the indicative range for a TMV install or service is in the price guide.
Licence & cover
TMV commissioning and servicing is licensed plumbing work in NSW. NSW Fair Trading contractor licence 498220C covers plumbing, drainage and gas fitting, with accreditation for thermostatic mixing valves and backflow prevention. The business carries $20 million public liability cover (ABN 51 697 209 153).
NSW rules
Which sites need a TMV, and how often is it tested?
The requirement comes from NSW Health’s hospital water policy and Building Commission NSW’s advisory note on heated water temperatures. Field-testing and maintenance are set out in AS 4032.3 and the valve manufacturer’s instructions, so the interval depends on the type of facility.
- Hospitals and nursing homes
- Ablution outlets that patients can reach may only use an approved warm water system, usually a TMV. Each valve also gets a monthly temperature check from at least one outlet, with the reading recorded.
- Aged care, childcare, schools and disability facilities
- Hot water for personal hygiene must be delivered at no more than 45°C in the residential part of an aged care building, patient care areas, the parts of early childhood centres and schools that children use, and facilities designated for people with a disability. The device has to be a thermostatic mixing valve or a thermostatically controlled tap.
- New hot water services and heater replacements
- Everywhere else the limit is 50°C. A temperature control device is required on a new heated water service and whenever the water heater is replaced. It can be a TMV, a thermostatically controlled tap, a tempering valve or a water heater limited to 50°C.
The temperature ranges, the monthly hospital check and who may do the work are set out in TMV testing in NSW: who needs it and how often.
How it runs
What a TMV test covers
Hot water is stored at 60°C or more to control Legionella, which is hot enough to scald. The valve mixes in cold and holds a set warm temperature at the tap. The test proves it still does that, and that it shuts off when it should.
Step 1
Inspect and clean
The valve is opened up and its components are inspected and cleaned.
Step 2
Check the non-return valves
The non-return valves are checked, so hot and cold cannot cross over.
Step 3
Set the temperature
The mixed temperature is set at the outlet and the reading is recorded.
Step 4
Thermal shutdown test
The valve has to shut off the hot water if the cold supply fails.
Step 5
Write it up
The report lists the outlets served, the temperature range, any parts replaced and the next service date.
Which valve is which
TMV, tempering valve or backflow device?
The three get mixed up, and a site can have all of them. A TMV protects the person at the tap. A backflow device protects the drinking supply.
- Thermostatic mixing valve
- Blends stored hot water with cold and holds a set warm temperature at the outlet, with a thermal shut-off. It is tested and serviced, and the result is written up for the owner.
- Tempering valve
- Also a temperature control device, and one of those allowed where the limit is 50°C. At the 45°C sites a tempering valve is not on the permitted list.
- Backflow prevention device
- A different device with a different job: it protects the drinking supply, not the person at the tap. A testable one is tested every year and the result is lodged with the water authority.
Backflow testing explained covers the device on the water service. Strata, real-estate and commercial sites are on the commercial plumbing page.
Good to know
TMV testing: common questions
Is a TMV test report lodged with Central Coast Council or Hunter Water?
No. Unlike a backflow device, a TMV result is not lodged with the water authority. You receive a written commissioning or maintenance report covering the tests done, the temperature set and the next service date, and it stays with the owner.
What happens if a TMV fails its test?
If the valve will not hold temperature or will not shut down, it is repaired or replaced and then retested. That is licensed plumbing work, not an adjustment to make yourself. We quote the repair or the new valve before doing it.
Does an NDIS or accessible bathroom need a TMV?
In NSW, hot water for personal hygiene in any facility designated for use by people with a disability must be delivered at no more than 45°C, and the device has to be a thermostatic mixing valve or a thermostatically controlled tap. Whether a private home comes under that rule depends on the building, so we confirm it for the job. We set accessible bathrooms out and fit the valve as part of the renovation plumbing.
Can backflow testing and TMV servicing be done on the same visit?
Yes. Both are part of our regular compliance work, and they can be put on a schedule so nothing lapses. The backflow result is lodged with the water authority, and the TMV report stays with you.
How often does a TMV have to be tested?
It depends on the facility. Field-testing and maintenance are set out in AS 4032.3 and the valve manufacturer’s instructions. Hospital warm water systems also have a monthly temperature check on each valve. We confirm the interval for your site when we see the valve.
What does TMV servicing cost?
The indicative range for a TMV install or service is in our price guide. The job is priced before any work starts, and a repair or a replacement valve is quoted once we have seen what is installed.
Where we test and service TMVs
Across the Central Coast, Lake Macquarie and Newcastle, from a base in Mannering Park.
Every suburb we cover is listed under service areas.
Customer feedback
What customers say.
Josh did an incredible job for us, the way he conducts himself is outstanding. Polite, respectful and great workmanship Highly recommend him.
Very happy with the service and the jobs we have had done. Turns up on time pricing is great and time frame to book was good I would recommend
Professional with high attention to detail