Hobart CL Series Booster Heater Scaling — Miami Water Profile

The Hobart CLeN, CLPS, and CLB conveyor dishwashers use either a built-in booster heater or an external booster, depending on configuration. The built-in booster is integrated with the final rinse manifold — 36 kW electric typically for the CLeN, sized to raise incoming supply water from 140°F to 180°F at the conveyor speed and water flow rate.

The booster element sits inside a stainless tank with a thermostat sensing the tank water temperature and a contactor cycling the element on demand. The element heats the water; the thermostat cuts off at setpoint. In Miami water (220 to 260 ppm hardness), calcium deposits steadily on the element over 12 to 24 months of service. Scale is thermally insulating — a scaled element at the same wattage delivers less heat to the water.

Stage one (year 1 to 2): final rinse hits 180°F at steady state but takes longer to recover after a heavy conveyor run. The booster is working harder than design but still meeting spec.

Stage two (year 2 to 3): final rinse meets 180°F at idle but drops to 172 to 178°F during heavy conveyor running. Health inspection on a busy day catches the low reading; same inspection at idle reads normal. This is the dangerous stage because the operator may not detect the problem in daily verification if the verification doesn't happen under load.

Stage three (year 3+): final rinse can't reach 180°F even at idle. The element is failing or the scale is heavy enough to fully insulate the heating surface. The unit either gets descaled, the element gets replaced, or the booster gets upgraded.

Descaling flushes calcium from the element and the tank. Lock-and-tag the unit, drain the booster tank, fill with Hobart Stera-Sheen at full strength, recirculate via the booster pump for the spec dwell time (typically 30 to 60 minutes), drain, rinse with potable water, refill, return to service.

Cost: $180 to $280 in labor plus chemical (Stera-Sheen is $42 a gallon, typically 1 to 2 gallons per booster). Effectiveness on a year-2 element: 85 to 95 percent of original capacity restored. Effectiveness on a year-3+ heavily-scaled element: 50 to 70 percent. If descaling brings the booster within spec, schedule subsequent descalings every 12 months on Miami water.

When descaling doesn't recover the booster to spec, the element is replaced. Hobart CLeN booster element: $180 to $260 OEM, 1 to 2 hours of labor plus the descaling of the tank during the replacement. Total: $400 to $620.

After replacement, the booster is functionally new. Service intervals reset. With water treatment upstream (next section), the new element's service life can match the original 5 to 8 year design life. Without water treatment, the new element will scale on the same timeline and be back in this situation in 18 to 30 months.

For chronic-scaling situations, an external booster (typically a 30-gallon or larger storage-tank gas booster from PVI, Lochinvar, or similar) replaces the built-in unit. The external booster has a larger water mass, longer dwell time, and is sized for higher demand than the integrated booster. Gas-fired models also have a different cost-of-operation profile than electric.

Install cost: $3,800 to $6,200 depending on gas availability and plumbing complexity. The external booster outlasts multiple Hobart internal boosters and is easier to service in place. For high-volume conveyor installations (hotel banquet kitchens, country club banquet, large institutional kitchens), the upgrade pays back in 4 to 7 years on reduced repair cost and reduced downtime.

All three options above are temporary without addressing the water. A water softener or RO system upstream of the booster removes the hardness driving the scale. Softener install: $1,400 to $2,800 with annual salt cost of $200 to $400. RO install: $1,800 to $3,400 with annual cartridge cost of $200 to $400.

With water treatment, booster service intervals stretch to the design spec (5 to 8 year element life, annual descaling instead of semi-annual). Without, the same descaling/replacement cycle repeats. For high-volume operators, water treatment pays back in 2 to 3 years on reduced repair cost alone.

Low-volume kitchen (under 200 racks per day, CLeN running 4 hours): annual descaling, accept the 5 to 7 year booster lifespan, replace element when needed. No water treatment investment needed.

Medium-volume kitchen (200 to 500 racks per day, running 8 to 10 hours): semi-annual descaling plus water softener install. Element replacement at 6 to 8 years.

High-volume kitchen (500+ racks per day, running 12+ hours): water softener or RO plus quarterly booster maintenance. Consider external booster upgrade if integrated booster is in original install and approaching 5 years.

Each booster service gets documented: pre-service final rinse temperature reading at idle and under load, descaling procedure performed, post-service readings, next-due interval. The log goes to the kitchen manager and stays in our dispatch system.

DBPR inspections in Florida verify final rinse temperature with a max-registering thermometer. A documented preventive maintenance schedule plus current temperature readings answers the inspection question without further inquiry.

Berne Commercial Repair services Hobart CLeN, CLPS, CLB, AM, and FT series warewashing equipment across Miami-Dade, Broward, and Palm Beach. Booster service, descaling, element replacement, external booster upgrades, water treatment coordination. $89 commercial service call — free if you approve the repair. Call (754) 345-4515 or request through our commercial dishwasher repair page.

For residential premium dishwashers and combi-ovens that scale in South Florida water (Miele G7000, Wolf CSO, Thermador), Berne's premium residential team covers descaling on the home side.