NEWDOSE Metering Pump Indicator Light Not On? Checking Power and the Control Board

When a customer calls to say "the light on the pump is out," our first question is always: which light? On a NEWDOSE metering pump, the answer depends on whether the power light is dead, or the power light is on and the working light just isn't flashing. The first usually means a supply or control board problem. The second often means nothing is broken at all; the pump simply isn't in run mode.

Know the Lights on the Panel

Every solenoid NEWDOSE metering pump in the DFD, DP, DM and DC series has two indicator lights. Power is the supply indicator and should light as soon as the pump is energized. Ω is the working status indicator: when the pump runs, the red light flashes at the stroke rate, so faster flashing means faster dosing.

On the DP and DM versions of the NEWDOSE metering pump, the panel adds an A/M manual/auto key and an ADJ function key, and the letters on the display also tell you the state:

• DP shows H for manual and P for external pulse control. In standby the green light flashes, and it stops flashing once Start/Stop puts the pump into run;
• On the small DP-LM models, watch the decimal point at the bottom right of the display: showing means stopped, gone means running;
• DM shows something like 120F when stopped in manual, and 000A in auto mode, where a flashing A means stopped and a steady A means running.

Mechanical diaphragm pumps are motor driven and have no such panel, so what follows applies mainly to solenoid pumps.

Power Light Off: Why a NEWDOSE Metering Pump Shows No Light

The troubleshooting table in the manual lists four causes for "pump cannot display or start". We suggest checking them in this order:

1. Wiring fault: check that the circuit breaker is on and the plug is secure. The manual calls for a breaker between pump and supply, and a tripped breaker is both the most common and the easiest fix;
2. Wrong voltage: compare against the nameplate. The standard supply is 220V 50Hz, and in the model code A means 230V and B means 115V. The wrong voltage can damage the pump outright or even start a fire;
3. Blown fuse on the control board: replace the fuse;
4. Failed control board: replace the board.

The first two can be confirmed at the terminals with a multimeter. The last two mean opening the housing. The manual states that internal inspection and repair of a NEWDOSE metering pump may only be done by factory-authorized staff, and damage from unauthorized opening is not covered by warranty. On site, confirm the incoming supply is good; if it is and the light is still off, call the factory.

Why a NEWDOSE metering pump blows fuses

Common triggers are unstable supply, the wrong voltage and miswired signal cables. The manual stresses that reversing signal polarity can destroy the board or the whole pump. Pulse voltage into a DP must not exceed 24V, and the DM current input takes 0/4–20 mA only; getting either wrong can also damage the board. If a new fuse blows again, something else is wrong, so don't keep swapping fuses.

Power Light On, Working Light Not Flashing

Plenty of people who ask why their NEWDOSE metering pump light is off turn out to have a perfectly good power light; it's the working light that isn't flashing. Before you call for service, check these:

The pump hasn't been started

With a NEWDOSE metering pump powered up, the Power light glows, but you still need to press Start/Stop before the pump begins working. After a power cut, check whether the pump is sitting in standby and needs Start/Stop pressed again.

It's in auto mode with no signal

In pulse mode, a DP strokes according to incoming pulses. If the water meter isn't turning and no pulses arrive, the pump doesn't move and the working light won't flash. In auto mode, a DM stops when the incoming current is below the set start current. Check the signal source and wiring, not the pump.

Also note that a DP can only switch between manual and auto while stopped. Some people press A/M while it's running, get no response, and conclude the panel is faulty.

The remote control input is active

Some models have a remote control input that takes a dry-contact signal, configurable as normally open or normally closed. If a level switch, timer or control panel is wired in and its contact state holds the NEWDOSE metering pump in stop, the panel looks as if nothing is working. Disconnect the remote signal and try manual operation.

NEWDOSE Metering Pump Diagnosis: When to Send It Back

For a failed control board or solenoid, the manual's remedy is a replacement board or a factory return. Garbled display, no response from any key, or a completely dark panel with good incoming voltage usually fall into this group. Warranty is one year, and damage from misuse isn't covered, so a second look at the terminal numbers during wiring saves a lot of trouble.

Ambient temperature should stay between 0 and 40 ℃, out of direct sunlight. The NEWDOSE metering pump is rated IP55, so ordinary splashes are fine, but standing water or direct hosing during washdown is hard on the board.

Conclusion

When a NEWDOSE metering pump indicator light is off, split the problem in two. If the power light is dark, check the breaker and wiring, nameplate voltage, fuse and board in that order. If the power light is on but the working light isn't flashing, check whether the pump was started, whether it's in auto mode waiting for a signal, and whether the remote input is holding it in stop. The manual's maintenance section also lists checking the panel lights, so add it to routine rounds and small problems surface early.

FAQ

The pump is running but the red light doesn't flash. Is that normal?

No. Per the manual, the red light flashes at the stroke rate while the pump runs. If the pump is clicking but the light stays dark, the indicator or control board may be faulty; contact the factory.

My NEWDOSE metering pump stopped after a power cut. Why?

Check that the power light is on, then whether the pump is in standby, and press Start/Stop. In auto mode, also confirm the external signal has come back.

Can I change the fuse myself?

The fuse is inside the pump, so it means opening the housing. The manual requires internal repairs by factory-authorized staff, so contact the factory to avoid affecting the warranty.

What should I have ready when reporting a NEWDOSE metering pump fault?

Model, nameplate voltage, control mode, a photo of the wiring, what the display shows, and what was done just before the fault appeared. The more complete the information, the faster the diagnosis.

A mechanical pump has no lights. How do I tell if it has power?

Watch whether the motor turns and the pushrod moves. If it has an electric stroke actuator or a VFD motor, check the supply and signal to each separately.

If you're unsure of the model or how to describe the fault, send us a photo of the panel through our contact page and we'll work through it with you.