Johnson Controls AS Trouble shooting chart, The pump does not prime, No flow, Insufficient flow

14.0 Trouble shooting chart

The pump does not prime

•Air has entered the suction piping; check the seals on the fittings and tighten them sufficiently.

•Suction pipe not submerged in liquid.

•Clearances between impeller/cover and impeller/body have increased. Check and correct.

•No liquid in the pump. Introduce liquid.

•Reduce loss of suction head; reduce the suction height.

•Formation of air pockets; eliminate and if necessary fit a valve on discharge.

No flow

•Pump not primed; (see point 8 and previous point).

•Pump turning in wrong direction.

•Suction port obstructed.

•On-off valves closed.

Insufficient flow

•Increased system back pressure on discharge side; increase piping diameter.

•Air entering mechanical seal; check its condition.

•Viscosity of fluid greater than that specified in the order. Contact manufacturer.

•Clearances between impeller/cover and impeller/body have increased. Check and correct.

Loss of head

•Back pressure on discharge side has fallen; throttle the suction pipe.

•Clearances between impeller/cover and impeller/body have increased. Check and correct.

Increase in absorbed power

•Flow rate is lower than required.

•Pump is turning at higher speed.

•The impeller does not turn freely. Check it.

•Viscosity and/or specific weight are higher than stated.

•Bearings are not in good condition.

Increase in absorbed current

•The power required has increased (see previous point).

•Main voltage value has fallen.

•There is a fault in the electrical system.

IM-AS/02.00 GB (0412) 27