Commercial Dishwasher Temperatures and Checks

A commercial dishwasher must both clean and sanitise. High-temperature machines sanitise with heat, typically washing around 60 degrees and delivering a final rinse near 82 to 85 degrees. Chemical (low-temperature) machines sanitise with a chlorine-based sanitiser at lower rinse temperatures. Whichever you run, you must verify it is working by checking gauges, rinse temperature or sanitiser dosing, and keeping simple records your local council inspector can see. Key takeaways: Cleaning removes visible soil; sanitising reduces micro-organisms to a safe level. A dishwasher must do both, in that order.. High-temperature machines rely on a hot final rinse (commonly around 82 to 85 degrees) to sanitise; chemical machines use a sanitiser dosed into a cooler rinse.. Verify the machine, not just trust it: check the wash and rinse gauges, test rinse temperature or sanitiser concentration, and confirm dishes come out clean and dry.. Keep a simple daily check record. Inspectors want evidence your sanitising step actually works, not just that a machine is present.. Descale, clean filters, replace worn wash and rinse arms, and service the machine so temperatures and dosing stay reliable.. High-temp vs chemical dishwashers at a glance: Feature, High-temperature machine, Chemical (low-temp) machine. Sanitising method — Hot final rinse (heat) — Chemical sanitiser in rinse. Typical wash tank temp — Around 60 degrees — Lower than high-temp. Final rinse — Commonly about 82 to 85 degrees — Cooler rinse with dosed sanitiser. What you verify — Rinse temperature reaches target — Sanitiser concentration on target. Main failure risk — Booster heater fails or scales up — Sanitiser empty, diluted or mis-dosed. Drying — Fast self-drying from heat — Slower; more air-dry time needed. Cleaning versus sanitising: why both matter Under the Australia New Zealand Food Standards Code, food contact equipment must be kept clean and, where it is used for potentially hazardous food, sanitised. These are two separate outcomes. Cleaning uses detergent, water and physical action to remove visible food, grease and grime. Sanitising then reduces bacteria, viruses and other micro-organisms on an already-clean surface to a level that will not make people sick. A dishwasher that only cleans, or only pushes hot water over greasy plates, is not delivering a sanitising step. Sanitising works reliably only on a clean surface, because soil shields micro-organisms from heat and chemicals. This is why scraping and pre-rinsing before loading matters, and why an overloaded or poorly maintained machine can leave items that look clean but are not sanitised. High-temperature (thermal) dishwashers High-temperature machines sanitise with heat. Water is heated in the machine and, critically, a booster heater lifts the final rinse water to a high temperature that both rinses detergent away and sanitises the load. As a widely used industry guide, the wash tank typically sits around 60 degrees and the final sanitising rinse is commonly in the range of about 82 to 85 degrees at the manifold. Because the surface temperature of the crockery, not just the water temperature, drives sanitising, items need to reach a high enough temperature for long enough. Signs a thermal machine is sanitising well include steam on opening, dishes hot to the touch, and rapid air-drying with no wiping. Confirm the exact target temperatures and cycle times against your machine's manufacturer specifications, as these vary by model. Wash tank temperature is commonly maintained around 60 degrees to loosen and remove soil.. The final rinse is the sanitising step and runs much hotter, commonly around 82 to 85 degrees.. A working booster heater is essential; if the booster fails, the machine cleans but may not sanitise.. Very hot rinse water helps items self-dry, reducing the risk of recontamination from cloths.. Chemical (low-temperature) dishwashers Chemical machines, sometimes called low-temperature machines, sanitise using a chemical sanitiser rather than heat. They wash and rinse at lower temperatures and inject a sanitiser, usually chlorine-based, into the final rinse at a controlled concentration. These machines are common where a booster heater or the electrical supply for high-temperature washing is not practical, and they cost less to run in energy. The trade-off is that sanitising depends entirely on the sanitiser being correctly dosed, at the right concentration and contact time, on a properly cleaned item. If the sanitiser drum runs empty, the dosing line blocks, or the product is diluted or expired, the machine stops sanitising even though it appears to run normally. Because dishes are not rinsed at high heat, they often need more time to air-dry. Sanitising relies on correct chemical dosing, not heat, so the sanitiser supply must never run empty.. Follow the sanitiser manufacturer's directions for concentration and contact time exactly.. Use test strips suited to your sanitiser to confirm the rinse concentration is on target.. Store, rotate and check sanitiser chemicals so you never dose with a diluted or expired product.. How to verify sanitising is actually happening Having a dishwasher is not proof of sanitising; verification is. For a high-temperature machine, check the built-in wash and rinse gauges each shift, and confirm the final rinse is reaching its target. Because in-built gauges can drift, periodically confirm the true rinse temperature. Options include a maximum-registering thermometer or temperature-sensitive label designed for dishwashers, or a calibrated waterproof probe used per the manufacturer's guidance. For a chemical machine, use test strips matched to the sanitiser to confirm the rinse concentration falls within the recommended range. For both types, inspect a sample of items from each cycle: they should be free of food, grease and film, and dry quickly. Any item that comes out soiled must be rewashed, not wiped and put away. High-temp: read the wash and rinse gauges every shift and periodically verify the true rinse temperature.. Chemical: use sanitiser test strips to confirm concentration in the final rinse.. Both: check that a sample of items is visibly clean, film-free and drying quickly.. Use thermometers and probes that are accurate and checked regularly (a common target is within about 1 degree).. Loading, running and unloading correctly Even a perfectly calibrated machine fails if it is used poorly. Scrape and, where needed, pre-rinse items so the wash water is not overwhelmed with soil. Load racks so water can reach every surface: do not nest bowls, stack plates flat, or overcrowd cutlery baskets. Let the machine complete its full cycle rather than opening it early, which can drop the rinse temperature or cut contact time. Change the wash tank water when it becomes heavily soiled, as dirty wash water reduces cleaning performance and can redeposit soil. Unload with clean hands onto a clean, sanitised surface, and let items air-dry rather than towelling them, which can reintroduce bacteria. Handle clean crockery and glassware by edges, bases and handles, not by food or lip contact surfaces. Maintenance that keeps temperatures and dosing reliable Dishwasher performance drifts over time unless it is maintained. Clean the machine's filters, strainers and wash tank daily so debris does not block spray jets or foul the water. Descale regularly, because scale build-up on heating elements and in booster heaters reduces their ability to reach and hold sanitising temperatures, especially in hard-water areas. Inspect wash and rinse arms and nozzles for blockages and wear so spray coverage stays even. For chemical machines, check dosing lines, pick-up tubes and the sanitiser supply so concentration stays consistent. Arrange servicing per the manufacturer's schedule, and have gauges and dosing verified during service. Keeping the machine in good order is not just about longevity; it is what keeps your sanitising step working every day. Checklist: Machine filled, heated and gauges in normal range before first load. Final rinse temperature verified (high-temp) or sanitiser concentration tested (chemical). Items scraped and pre-rinsed before loading; racks not overcrowded. Sample of washed items checked: clean, film-free and drying quickly. Detergent, rinse aid and sanitiser topped up before running out. Filters and strainers cleaned; heavily soiled wash water changed. Daily check recorded and any faults reported and actioned. Common mistakes: Assuming a running machine is sanitising without ever checking rinse temperature or sanitiser concentration. Letting the sanitiser drum run empty on a chemical machine so cycles clean but no longer sanitise. Overcrowding or nesting items so water cannot reach every surface. Opening the machine mid-cycle and cutting the rinse temperature or contact time. Towel-drying dishes instead of air-drying, reintroducing bacteria to sanitised surfaces. Ignoring scale build-up so the booster heater can no longer reach sanitising temperature.