Commercial warewashers fail quietly. A Hobart AM15 or LXe that looks clean can still be skipping its sanitizing rinse temperature — and that is a failed health inspection waiting to happen, plus glassware that never really gets clean. This guide covers the warewasher failures we see most on San Diego service calls, what your staff can verify before open, and when to call before a slow machine becomes a closed kitchen.
1. Final Rinse Not Hitting 180°F (High-Temp Machines)
What You’re Seeing
High-temp Hobart machines (AM and LXe series) sanitize with a 180°F final rinse driven by a built-in booster heater. When the booster element or its thermostat fails, the wash still runs but the rinse drops below sanitizing temperature — the machine is no longer sanitizing even though dishes look done. Low-temp machines are different: they sanitize chemically with a chlorine sanitizer at around 120°F, so their failure is usually an empty sanitizer jug or a dead chemical feed pump.
On-Site Check (Staff)
Read the machine’s built-in wash and rinse gauges through a full cycle: high-temp should show roughly 150°F wash and 180°F final rinse. Confirm with a min-registering thermometer or a heat-sensitive thermolabel on a plate. On a low-temp machine, check the sanitizer level and pull a chlorine test strip from the final rinse.
When to Call a Tech
Call us if: The rinse gauge will not climb to 180°F, the booster heater trips its breaker, or the chemical sanitizer is not being drawn in — a sanitizing failure is a same-day call, not a ‘next week’ repair.
2. Cloudy Glassware, Film and Spotting — Hard-Water Scale
What You’re Seeing
San Diego’s hard water leaves lime scale on jets, tank walls and the booster element, and leaves film or spots on glassware. Low rinse-aid, the wrong detergent concentration, or a clogged dispenser produce the same look. Left alone, scale on the heating element kills efficiency and eventually burns the element out.
On-Site Check (Staff)
Confirm detergent and rinse-aid reservoirs are full and the dispensers are dosing. Look inside the tank for chalky white buildup, and descale (delime) on schedule — see the maintenance section below. Wipe the door and gasket area where film collects.
When to Call a Tech
Call us if: You see heavy scale on the booster or heating element, the chemical dispenser is not metering correctly, or deliming no longer clears the film — a tech can descale the booster and verify dispenser draw.
3. Wash and Rinse Arms Not Spinning / Weak Spray
What You’re Seeing
Wash and rinse arms have to spin freely and spray through clear jets to clean. Food debris and scale clog the jets, and worn arm bearings stop them turning — the result is dishes that come out dirty no matter how many times you re-run them.
On-Site Check (Staff)
Remove the wash and rinse arms daily and rinse them out; clear each jet with a brush or pick. Empty and rinse the scrap screens. Spin each arm by hand — it should turn smoothly with no grinding.
When to Call a Tech
Call us if: An arm bearing is seized, the wash pump is weak or noisy, or you see a pump motor seal leaking — these are pump and bearing repairs, not a cleaning fix.
Down Equipment? Call Spark Appliance Repair
When commercial equipment goes down, every hour is lost service. Spark Appliance Repair is licensed and insured (California BHGS Registration #C 62399), EPA 608 Type I certified, and offers same-day service across San Diego County for calls received before noon, backed by a 90-day parts and labor warranty.
4. Won’t Drain or Slow to Fill
What You’re Seeing
A warewasher that will not drain (or drains slowly) usually has a stuck drain valve or a clogged drain line; one that will not fill has a fill solenoid or float-switch fault, or the water supply is throttled. Standing dirty water in the tank is both a sanitation and a downtime problem.
On-Site Check (Staff)
Clean the scrap screens and check the drain and overflow for debris. Confirm the water supply valve is fully open and the building has hot water. Power-cycle the machine at the disconnect.
When to Call a Tech
Call us if: The drain valve motor has failed, the fill solenoid is not energizing, or the float is stuck — the machine needs a valve or solenoid, not another screen cleaning.
5. Cycle Won’t Start — Door Switch, Contactor, Controls
What You’re Seeing
Hobart machines start the cycle from a door-activated switch and run the wash pump through a contactor. A failed door interlock, a chattering contactor, or a control fault will leave you with a machine that powers up but will not run a cycle.
On-Site Check (Staff)
Confirm the door is fully closed and latched, the disconnect and breaker are on, and note any indicator lights or error display. Power-cycle once — if the cycle still will not start, stop and call.
When to Call a Tech
Call us if: The door switch has failed, the contactor is chattering or welded, or the control board is faulting — these are electrical repairs for a licensed tech, not a reset.
6. Hobart Warewasher Maintenance Schedule
Most warewasher service calls trace back to skipped maintenance — scale and debris, not worn-out machines. A serviced Hobart runs 15–20 years; a neglected one burns a booster element or wash pump in 3–5. Build this into the closing routine:
Daily
- Clean scrap screens and remove/rinse the wash and rinse arms
- Wipe the door gasket and tank; drain and refill clean water
- Check detergent, rinse-aid and (low-temp) sanitizer levels
- Verify wash and rinse temperatures before service starts
Weekly
- Deep-clean the tank and inspect every spray jet
- Check rinse-aid draw and dispenser dosing
- Inspect door gaskets for tears or hardening
Monthly / Quarterly
- Delime (descale) the tank, jets and booster — sooner for high-volume bars in San Diego’s hard water
- Inspect the booster element and drain valve
- Have a tech verify sanitizing temperatures and chemical draw
Related Spark Pages
- Commercial Dishwasher Repair San Diego
- Commercial Appliance Repair San Diego
- Commercial Ice Machine Repair
- Residential Dishwasher Repair
- Dishwasher Not Cleaning Dishes? 7 Reasons Why
Frequently Asked Questions
Why would a commercial warewasher suddenly stop sanitizing?
What temperature does a commercial dishwasher need to sanitize?
How often should a Hobart warewasher be delimed?
Do you offer same-day commercial dishwasher repair in San Diego?
Which commercial dishwashers do you service?
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