When a Hobart dishwasher stops heating or draining, the health inspector problem shows up fast: high-temperature machines have to hit their final rinse temperature to sanitize. This guide walks through the four complaints we hear most on Hobart door-type, undercounter, and conveyor machines, and what to check for each.
Safety first: dish machines combine water, high voltage, and hot surfaces. Turn off power at the disconnect and let the machine cool before opening panels. Booster heaters run very hot.
1. Not Heating, or Rinse Temperature Too Low
High-temperature machines generally need wash water in the 150–160°F range and a final rinse of at least 180°F at the manifold. Check the data plate for your machine’s exact requirements. If the rinse thermometer reads low:
- Low water level: tank heaters are interlocked so they won’t energize without enough water. A stuck float or a dirty level probe can shut the heat off even when the tank looks full.
- Booster heater: check that the booster is powered and its breaker hasn’t tripped. Scale buildup on the booster element is a slow killer in hard-water areas.
- Heating element: a failed tank or booster element. With power locked out, test for continuity.
- Thermostat or temperature probe: a drifting control can cut heat early.
- Incoming water temperature: boosters are sized to raise water a set amount. If the building’s hot water supply has dropped, the booster can’t catch up.
- Rinse thermometer: confirm with a second thermometer before replacing parts. A bad gauge is a cheap fix.
2. Not Filling, or Filling Slowly
- Water supply: make sure the supply valve is fully open.
- Inlet strainer: a clogged line strainer is the most common cause of a slow fill. Clean it.
- Fill solenoid valve: if you hear the valve energize but get no water, or hear nothing at all, the solenoid coil or valve has likely failed. A valve that won’t close causes overfilling and water running to the drain.
- Water pressure: rinse performance depends on flow pressure. Low building pressure causes weak rinsing as well as slow fills; many machines need a pressure regulator set to the manufacturer’s specification.
3. Not Draining
- Scrap screens and baskets: clean them first. They clog with food debris every shift.
- Drain hose or line: look for kinks, crushed sections, and grease buildup.
- Drain valve or pump: gravity-drain machines use a drain valve; pumped-drain machines use a drain pump. A pump that hums but doesn’t move water is usually blocked or failed.
4. Dishes Coming Out Dirty or Spotted
- Wash and rinse arms: pull them, flush the nozzles, and make sure they spin freely. A single clogged nozzle leaves a dirty stripe.
- Lime scale: scale on the arms, heaters, and tank reduces both cleaning and heating. Delime on the schedule your water hardness demands.
- Chemicals: confirm the detergent and rinse aid are feeding. Empty or kinked chemical lines are common.
- Water temperature: low wash temperature leaves grease behind. See section 1.
Hobart Dishwasher Parts in Stock
- Hobart 01-3PB020 water solenoid valve
- Hobart 00-328994 rinse probe assembly
- Hobart 00-328696-0000 rinse thermometer
- Hobart 00-122345-0000 heater assembly, 200–230V
- Hobart 00-478220-0000 heater, 208V
- Hobart 00-292856-00002 drain hose, 5/8"
Heaters and solenoids differ by model and voltage, so confirm against your machine’s parts list before ordering.
Not sure which part fits your unit? Parts vary by model, serial range, voltage, and gas type. Send your model number, serial number, and the symptom to our parts desk and we’ll confirm the right part before you order.
Frequently Asked Questions
What temperature does a Hobart high-temp dishwasher need?
Typically a wash temperature in the 150–160°F range and a final rinse of at least 180°F. Your machine’s data plate and your local health code are the final word.
Why won’t my dishwasher heat even though the tank is full?
Heaters are interlocked with the water level control. A stuck float or dirty level probe can tell the machine the tank is low, so the heat stays off.
How often should a commercial dishwasher be delimed?
It depends on water hardness and volume. In hard-water areas it can be weekly. Visible white scale on the arms or tank means it’s overdue.
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