Contents

1. Search intent & how to use this guide
2. Common symptoms in summer (and what they usually mean)
3. 10‑minute DIY triage (safe checks anyone can do)
4. Red‑line conditions—when to stop and call a licensed tech
5. Why fridges sweat or leak in humid weather (dew point, infiltration & anti‑sweat heaters)
6. Climate class 3 / 4 / 5—when the “fault” is really a spec mismatch
7. Compliance corner: FSANZ 5 °C rule, the 2‑hour/4‑hour rule, cooling times
8. Energy & cost: turning kWh/24 h into dollars (and how anti‑sweat control helps)
9. Real‑world case notes (Chatswood NSW · Perth WA · Brisbane QLD)
10. Prevention plan: weekly/monthly tasks that actually work
11. FAQ
12. Book your 15‑minute Ambient & Drainage Remote Check
13. Related categories & parts on KW Commercial Kitchen

Search intent & how to use this guide

Primary intent: information—operators want a trustworthy, step‑by‑step answer to “Why is my commercial fridge leaking water or fogging up?” and “How do I fix it safely?”.

Secondary intent: commercial investigation—choose the right commercial grade cabinet for a Professional Kitchen in Australia (e.g., climate class upgrade, door‑gasket replacement, or switching to a display model designed for higher ambient humidity).

Use the 10‑minute triage first. If you hit any red‑line condition, stop and book service. Then read climate class to ensure you own the right specification for your venue’s ambient conditions. Throughout, we reference official sources so your team can meet food‑safety expectations in Australia.

Common symptoms in summer (and what they usually mean)

In Australian summer conditions (for example, 30 °C with 55–75% RH indoors), we see three locations where issues show up most:

1. Glass‑door display fridges (including cake displays) — most prone to fogging/condensation on glass, and “sweating” frames, especially if anti‑sweat heaters are off or under‑controlled, or if indoor dew point is high.
2. Undercounter/workbench fridges — often external puddles from blocked defrost drains and poor ventilation when the cabinet is built‑in tightly under benches or near dishwashers and ice machines.
3. Upright storage fridges — more likely to show internal pooling after defrost cycles if the cabinet isn’t level or the drain pan is damaged; glass‑door versions can fog in humid stores.

Below is a field‑tested table mapping symptoms to likely causes, quick checks, safe fixes, and risks. It’s designed for a Commercial Kitchen team to action fast.

10‑minute DIY triage (safe checks anyone can do)

This sequence is safe for most operators. It respects food‑safety limits and avoids electrical work.

1. Power down safely and cordon off any wet floor. Wipe standing water so you can see fresh drips clearly.
2. Level check. Place a spirit level on the cabinet top. Shim feet until the bubble centres—front‑to‑back and side‑to‑side. A few millimetres off can cause condensate mis‑routing.
3. Drain clear. Locate the defrost drain in the cabinet liner near the evaporator. Warm water flush plus a soft brush or flexible nylon line will clear most blockages. Avoid metal wire that can pierce linings.
4. Pan & airflow. Inspect the condensate pan above the compressor. If warped, cracked or overflowing, replace it. Make sure condenser fans aren’t blowing directly across the pan edge (which can flick water).
5. Gasket test. Close a banknote in the door on all four sides. If it pulls out easily, the gasket is leaking. Order a replacement by model/serial, or speak with our team for a parts match.
6. Ambient & dew point reality check. If you can read indoor RH from your store A/C or a simple hygrometer, note it. Very humid afternoons push dew point upwards and make glass fogging far more likely (more on that below).
7. Restart & observe. After 30–60 minutes of operation, check for new drips and confirm set temperature is holding.

Tip: If the issue returns within 24–48 hours after a good drain clear and re‑level, the root cause is probably a failing component (fan, heater, drain valve) or a spec mismatch with your ambient conditions. Move to red‑line checks and climate class.

Two quick flows to choose the next step

Outside leak →




(1) Is cabinet level? — No → Level and recheck → (Resolved?)
Yes → (2) Drain clear? — No → Flush with warm water → Recheck
Yes → (3) Pan intact? — No → Replace pan
Yes → (4) Condenser airflow blowing across pan? — Yes → Redirect/baffle
No → (5) Call technician (pump/fan/heater)

Fogging →




(1) Indoor RH/Dew point high? — Yes → Dehumidify / increase A/C → Check anti‑sweat → Recheck
No → (2) Anti‑sweat heaters on? — No → Enable/repair → Recheck
Yes → (3) Gasket sealing? — No → Replace gasket
Yes → (4) Upgrade climate class / review case placement

Red‑line conditions—when to stop and call a licensed tech

• Temperature control failure: the fridge cannot maintain ≤ 5 °C for potentially hazardous food. Stop use for high‑risk items and follow FSANZ’s advice on time/temperature control and disposal.
• Repeated leaks within 48 hours after a proper drain clear and re‑level.
• Electrical issues: tripping breakers, burnt smells, damaged anti‑sweat wiring, or fan motors that won’t start.
• Severe icing around the evaporator or evidence of refrigerant issues.

For any red‑line, book a licensed refrigeration technician. If you’re in NSW/VIC/QLD/WA, our team can coordinate service and parts.

Why fridges sweat or leak in humid weather (dew point, infiltration & anti‑sweat heaters)

Condensation is physics, not bad luck. Moist air condenses into water when it contacts a surface colder than the air’s dew point. On sticky days, the dew point rises. Glass doors and cold mullions sit well below that dew point, so they fog or “sweat.” Anti‑sweat heaters warm the glass/frame just enough to stay above the dew point, keeping visibility clear in display applications. That’s why glass‑door fridges can look fine in winter yet fog up in a humid summer afternoon.

Door‑gasket leaks and hinge sag add a second problem: infiltration of warm, humid air into the cabinet. That extra moisture must be removed by the evaporator; during defrost, it becomes water that should drain away. If the drain is blocked or the cabinet is not level, water ends up on the floor.

Takeaway: if your glass is fogging only on high‑humidity days and anti‑sweat heat is off or minimal, it’s likely an ambient/dew‑point issue rather than a refrigeration failure. If doors fog even in dry weather, look first at gaskets and door alignment.

Climate class 3 / 4 / 5—when the “fault” is really a spec mismatch

Refrigerated display cabinets are tested at standard ambient conditions called climate classes. The most common are:

Therefore, if your store regularly sits near 30 °C with moderate humidity, a Class‑3 glass‑door case may fog even when it’s “working to spec.” Upgrading to a cabinet designed/tested for Class‑4 (or in extreme sites Class‑5) conditions, paired with realistic anti‑sweat control and dehumidification, is more reliable than endless call‑outs.

Compliance corner: FSANZ 5 °C rule, the 2‑hour/4‑hour rule, cooling times

In Australia, professional kitchens must keep potentially hazardous food either at 5 °C or colder, or 60 °C or hotter, whenever it’s received, stored, displayed or transported. When food is temporarily out of temperature control—for example, while re‑merchandising a display—the 2‑hour/4‑hour rule applies. Cooling cooked food has its own timing requirement.

• Cold holding: aim for ≤ 5 °C in refrigerated storage and display. If you use an alternative time/temperature method, you must be able to show it’s safe.
• Time as a control (2‑hour/4‑hour rule): up to 2 hours between 5–60 °C → use/sell or return to refrigeration; 2–4 hours → use/sell but do not return to refrigeration; 4+ hours → discard.
• Cooling cooked potentially hazardous food: cool from 60 °C to 21 °C within 2 hours, then from 21 °C to 5 °C within 4 hours.

Why this matters here: leaks and fogging can be early warning signs of temperature instability. If your cabinet can’t keep ≤ 5 °C, take immediate action: move stock to a safe unit, log times, and fix the cause. Failing to follow these rules can lead to product loss, regulatory action, and reputational damage.

Energy & cost: turning kWh/24 h into dollars (and how anti‑sweat control helps)

Commercial fridges and refrigerated display cabinets are regulated under Australia’s Equipment Energy Efficiency program. Many product classes use an Energy Efficiency Index (EEI) and are registered on the national database. While an Energy Rating Label isn’t always mandatory for every cabinet type, the registration and EEI framework are.

Quick cost check

To translate a spec sheet into running cost:

1. Find the cabinet’s energy use (kWh/24 h) on its data sheet or the Energy Rating registration.
2. Multiply by 365 to get kWh/year.
3. Multiply by your tariff (e.g., $0.28–0.40 per kWh in many commercial plans) for annual dollars.

Example: If a case uses 8.0 kWh/24 h and your tariff is $0.32/kWh → 8.0 × 365 × 0.32 ≈ $934/year. If anti‑sweat heaters run unnecessarily at full power, real‑world consumption can rise; controls that follow dew point can often reduce heater runtime while keeping glass clear. Always follow manufacturer guidance.

Real‑world case notes (Chatswood NSW · Perth WA · Brisbane QLD)

Prevention plan: weekly/monthly tasks that actually work

FAQ

Is foggy glass illegal?

No. Fogging itself isn’t a breach. However, if fogging points to temperature instability and potentially hazardous food warms above 5 °C, you must follow FSANZ time/temperature rules, record what happened, and discard food that exceeds safe limits.

Can I switch off anti‑sweat heaters to save energy?

Only if visibility and safety remain acceptable in your store’s humidity. Anti‑sweat heat keeps surfaces just above the dew point. In dry conditions, controls can reduce heater output. In humid conditions, turning heaters off leads to fogging and drips. Follow the manufacturer’s instructions or speak with a technician.

My seafood program likes near‑freezing temps. Is −5 °C in a fridge OK?

Be careful. Near‑freezing “superchill” practices for seafood sit around the initial freezing point of the product (often near −1 °C), sometimes 1–2 °C below, and are not typical fridge setpoints. For retail/service cabinets, follow equipment and food‑safety guidance to avoid partial freezing and texture damage. Always keep records that demonstrate safe control.

What’s the fastest way to stop water on the floor during service?

Contain the slip hazard, then check the drain and level first. If those are fine, inspect the pan and look for airflow blowing across it. Persistent leaks need a technician.

Do open displays always sweat more?

Open displays admit more ambient air by design, so on humid days the load is higher. Use models suited to your climate class and fit night blinds. If fogging persists, review ambient humidity and case placement away from steamy prep zones.

Book your 15‑minute Ambient & Drainage Remote Check

Most leaks and fogging are solvable without drama—if you follow the right sequence. We’ll help you confirm the cause and choose the lowest‑cost fix.

• Phone: 1300 001 366
• Contact form: Request a callback in a few hours
• WhatsApp: message us via the website chat (typical response time: a few hours)
• Service areas: on‑site installation in major cities, warehouse pickup, and Australia‑wide shipping

Related categories & parts on KW Commercial Kitchen

• Commercial Fridges (all) — upright, undercounter, glass‑door and more for Professional Kitchens.
• Cake Display Fridges — for premium merchandising with anti‑sweat considerations.
• Commercial Upright Fridges — storage workhorses for back‑of‑house.
• Open Display Fridges — choose Class‑4/5‑ready models with night blinds for hot stores.
• Spares for Fridges & Freezers — door gaskets, drain parts, pans and more.