Dishwasher Washing Cooler Every Year, White Scale Wrapped Around the Heater? NL-DHH-6 Heater Scale and Power Decay Test Bench, Six Stations (dishwasher test equipment)

Dishwashers a year or two old start washing poorly, finish with the dishes barely warm, dry badly and leave an oily film with white water marks, and when the heater is pulled out it is wrapped in a layer of white scale thick enough to scrape off. In hard water areas this happens within six months. Calcium and magnesium salts deposit on the sheath, the layer adds thermal resistance, the delivered heating power is absorbed by the scale, the water never reaches its setpoint and the detergent stops working. The line checks one heat-up time on a new unit; power decay, insulation resistance and whether boil-dry protection still trips after scaling are all unknown before shipment.

What the NL-DHH-6 heater scale and power decay test bench measures

• Six stations in parallel circulating water at a set hardness over the heater, building the scale layer round by round, with heating power, heat-up rate and time-to-setpoint re-measured at intervals and the power decay curve plotted (the heater branch of our dishwasher test equipment)
• Scale thickness against thermal resistance: the same heater lot compared across hardness levels to quantify how water quality eats heat-up capability
• Boil-dry and low-water protection with a drained sump, logging trip time, reset behaviour and sheath temperature rise
• Insulation resistance and withstand voltage in the scaled and damp state, screening out seals that let moisture in
• Closed-loop wash and rinse temperature accuracy and band width, judging heater and controller matching
• Barcode and batch binding, with raw data exported per unit for heater lot comparison

Applicable standards

GB 4706.1 (household appliances – general safety), GB 4706.25 (dishwashers – particular requirements), IEC 60335-2-5 (dishwashers – particular requirements), GB/T 20290 (electric dishwashers – methods for measuring performance) and GB/T 2828 sampling; criteria can follow the customer’s standard and the rated water temperature and heating power.

Stations and throughput

Six stations running 24/7 turn the manual routine of boiling hard water, cutting a heater open and timing a thermometer into one automated cycle, with power decay and heat-up rate rechecked round by round — so incoming heaters and end-of-line dishwashers can both be sampled batch by batch, stopping lukewarm washes and oily films before shipment.

Manufacturer

Guangdong Endurance Electronic Equipment Co., Ltd. — a non-standard testing equipment manufacturer of dishwasher heater scale and power decay benches, dishwasher test equipment, washing machine test equipment, pump test bench and pump performance test systems and level sensor life test machines.

Keywords: pump test bench, pump performance test, level sensor life test, dishwasher test equipment, washing machine test equipment.