Common commercial jobs
- Kitchen drains that keep blocking with grease, and grease trap repairs or upgrades.
- Backflow device testing, repairs and new devices: see backflow testing.
- Commercial hot water that cannot keep up, or temperature control in care settings.
- Toilets, urinals and basins in shared amenities.
- Low pressure on upper floors: see water pressure.
- Plumbing for a tenancy fit-out or a change of use.
- Planned maintenance so faults are found before opening hours, not during them.
What a commercial plumber will do
A commercial plumber will usually start with the site: where the isolation valves are, what devices are fitted, and what records exist. From there, the work is a mix of fixing faults and keeping the site's compliance items up to date, such as backflow tests and temperature control valves.
For food businesses, grease is the constant. A plumber clears blocked kitchen lines, repairs or replaces grease traps, and can tell you whether the trap is the right size for the kitchen it serves. Pumping out a trap on a schedule is often done by a liquid waste contractor. If your business has a trade waste agreement, check what it says about the trap and the records you must keep.
For fit-outs, a plumber works from the design to rough in and fit off sinks, amenities and equipment, and handles the paperwork for the work at the end.
What changes the job
Access is often the biggest factor: work outside trading hours, ceiling spaces, plant rooms and shared risers in multi-tenant buildings. The number and type of fixtures, the age of the building and whether drawings exist all matter. So does who is responsible: your lease decides whether the landlord or the tenant pays for a given repair, so check it before booking.
Hot water rules in care and education settings
The building code sets a lower delivery temperature of 45°C in four settings: the residential part of an aged care building, a patient care area in a health care building, the parts of early childhood centres and schools used by children, and any facility designated for use by people with a disability. To meet it, only a thermostatic mixing valve or a thermostatically controlled tap is allowed.
Elsewhere, hot water at fixtures used for personal hygiene is limited to 50°C. Stored hot water is kept at 60°C or more to control Legionella, so the delivery temperature is brought down by a valve or a temperature-controlled tap, never by turning the heater down.
Licences: check before work starts
In NSW, a contractor licence is required for plumbing whatever the value, and the state's Public Register shows conditions, suspensions, public warnings and penalty notices against a licence. In Western Australia, a licensed plumbing contractor must put the licence number in its advertising and on business documents such as quotes, invoices and receipts. In Tasmania, a person must not carry on business as a contractor unless they hold a contractor licence.
Some commercial work needs a particular licence class. In the ACT, for example, the classes include "Fire sprinkler fitter" and "Advanced sanitary drainer" alongside general plumbing classes. Ask which class covers your job, and check it on the register; see how to check a plumber's licence.
Victoria's gas rules and commercial buildings
The Victorian Premier's announcement on gas says there are no changes to end-of-life replacement rules for gas appliances in existing commercial buildings. New commercial buildings, other than industrial, manufacturing and agricultural buildings, are to be built all electric from 1 January 2027. Check the current rules before planning a new building.
What your staff can do
You can
- Scrape plates into the bin and use sink strainers so grease and food stay out of the drains.
- Know where the main isolation valve is and keep the route to it clear.
- Keep a log of faults, test reports and certificates in one place.
- Report slow drains and running toilets early, before they become a closure.
- In Queensland and Western Australia, a few small tasks are open to anyone; see what you can do yourself.
Leave to a licensed plumber
- Grease trap repairs, replacement and drain clearing.
- Backflow testing, servicing and new devices.
- Thermostatic mixing valves and temperature control.
- Fit-out plumbing and anything that needs a compliance certificate.
Questions to ask the plumber
- Which licence classes do you hold, and do they cover this work?
- Can you work outside our trading hours?
- Will you lodge the paperwork for this job and give us a copy?
- Can you test our backflow devices and service our mixing valves on the same visit?
- Do you carry public liability insurance for commercial sites?
What we would do
Use the same plumber each time so they learn your site: where the valves are, what devices are fitted, and when each test is due. A short planned visit outside trading hours usually costs less disruption than an emergency during service. For food businesses, deal with grease at the sink before it reaches the trap. And always check the licence class on the register before a fit-out starts. We would look for a plumber who does commercial work week in, week out and is used to working around open businesses.