Troubleshooting

(This section applies to MD1 pumps produced after 1/5/2026. For MD1 pumps produced before this date, go to the MD1 Legacy Help Center pages.)

Common Issues 

Air is entering the pump.  Check suction lines to make sure all connections are tight. Check the level of the chemical tank.  Remove obstructions and clean strainers.  

Pump is not accurate.  Check and clean ball checks.  Clean the strainer and check for obstructions in suction lines, discharge lines, and injectors.  Check discharge and ensure some back-pressure (15 psi or more) is present.  

The Display reads “FvS”.     The flow Verification System has triggered.  Solution flow may not be present in the system. Check signal from the flow sensor.  If no flow sensor is connected, disable FVS function to prevent false triggering.   

The Display reads “SIG” or “SBY.” This indicates that the pump is ready and waiting for a remote signal from the PLC or other control system. This is normal. If the pump is not connected to a remote signal circuit, disable this function. 

Solution/chemical is leaking from the top or bottom fittings/connectors.  Check to ensure o-rings are present and seated properly. Check tubing connections and tighten as necessary. Check to make sure ball checks are installed properly. Ensure the pump is not overpressurized.  

Electricals 

The MD1 will not power up. Check power source or try a different power source.  Check to ensure the power cable is properly inserted in the bottom receptacle of the pump.  

The Remote Start/Stop is turning on/off or chattering. Check the integrity of the M12 cables and their proper connection to the pump. Check that all signal cables are shielded and properly grounded. Ensure signal wiring is not located or run next to high-voltage power or equipment generating EMI. Ensure the power wiring to the pump is clean and conditioned.  

The 4-20mA signal is dropping or incorrect.  Check M12 cables integrity and proper connection to pump. Ensure 4-20mA signal is powered via 15-24VDC. Check that all signal cables are shielded and properly grounded. Ensure signal wiring is not located or run next to high voltage power or equipment generating EMI.  Ensure power wiring to the pump is clean/conditioned.  

The Display reads “E04” or other error code.  See the below chart and contact the factory for assistance.  Some error codes are corrected with a current Firmware Update.  See System section for details on firmware updates.