Install Instructions
installation &
operating instructions
Astro 2, 3-speed
circulator models
7
fault possible cause remedy
Pump stopped,
no power
Power supply interrupted
• Check the power supply. Attach external power control
if necessary.
Fuse tripped or circuit breaker opened
• Repair short-circuited wire. Repair loose contact.
• Check for the properly rated fuse.
• Check pump motor and lead.
Pump stopped, power
supply present
Thermal switch has actuated
• Reduce ambient temperature.
• Clean blocked or slow rotating pumps.
Pump does not start
• Open air vent screw and unlock shaft. Clean pump.
• Increase speed/set point.
• Replace pump.
Noises in system, ther-
mostatic valves/pipes
Pump output too high
• Reduce speed level.
• Open bypass/valve.
• Install circuit balancing valves to adjust fl ow.
• Check pump selection/system. Adjust pump. Check
system /gauges.
• Replace pump.
Noisy pump Air in pump
• Open bleed screw and vent pump. Vent and top up
system with water.
• Check expansion tank.
• Install air separator.
Cavitation sounds
• Increase inlet pressure.
• Reduce temperature.
• Throttle back pump.
• Reduce speed.
Resonance noises
• Use sound insulation material between the pump
and surface to reduce resonance noise. Install
expansion joints. Install fi xture to change system’s
natural frequency.
• Adjusts pump speed.
• Replace pump/motor.
Knocking from foreign bodies in the
pump/or on valve
• Clean impeller.
• Adjust valve pressure. Adjust valve spring.
• Turn valve around if installed incorrectly.
• Replace pump.