Bissell HS-20 Manuel D’Utilisation

Poor ultimate

Contaminated pump fluid

Examine and clean pump;

pressure

replace fluid.

Low heat input

Check voltage. Check for 
continuity, burned-out element,
poor thermal contact.

Inadequate cooling water flow

Check water pressure. Check 
tubing for obstructions and 
backpressure.

Excessive or too cold cooling water

Check temperature. Adjust flow.

High forepressure

Check for leak in foreline, poor
mechanical pump performance,
breakdown of mechanical 
pump fluid.

Water in quick-cool coil

Check and remove cause.

Low heat input

Check heaters.

Low fluid level

Add fluid.

Malfunctioning pump assembly.

Check and repair or 

Improperly located jets. Damaged

replace.

jet system.

Inlet pressure surges

Incorrect heater input

Check and correct.

Fluid outgassing

Condition fluid by operating the
pump for a few hours.

Leak in system ahead of pump inlet

Check and correct.

High chamber

Forepressure too high

Check for leak in foreline, poor 

contamination

mechanical pump performance,

breakdown of pump fluid, and 
incorrect valve operation.

Prolonged operation at high

Review procedures.

throughput at pressure above10

-3

Torr

Improper system operation and

Review procedures.

air release procedures

Pump will not start

Safety circuits and/or protective

Check utilities, flow devices

prevent contactor from 

switches, interlocks. Check

staying closed

thermostat operation.