HYDROSET PM821 user manual
Hardware A3.3 · software 4.0 — the full text, searchable.
The HYDROSET PM821 user manual covers installation, commissioning, the fifteen settings parameters F1 to F15, the eight fault codes and the technical specifications. The full text is reproduced on this page so it can be searched without downloading the file.
What does a water pump controller do?
A water pump controller is an electronic controller that starts and stops the pump according to water pressure. HYDROSET PM821 starts the pump when the pressure drops and stops it when the pressure reaches the set value. It protects the pump at the same time: if there is no water, if the pump current rises too high, or if the sensor fails, the unit stops the pump and shows a fault code.
- Holds the water pressure steady.
- Ramps the pump up and down softly so the pump lasts longer.
- Stops the pump if the water runs out, and retries on its own.
- Works both with and without a pressure vessel.
- Suits buildings, shops and gardens.
Model selection guide
| Pump current | Pump power | Model | Typical use |
|---|---|---|---|
| up to 8 A | up to 1.5 kW | PM821-8 | 1–4 floors, homes and shops |
| 8 – 16 A | up to 3 kW | PM821-16 | 5–10 floors, booster sets |
| up to 25 A | up to 4 hp | PM821-25 | Residential, commercial and agricultural |
The current on the pump nameplate decides the model, nothing else.
Settings parameters F1 to F15
HYDROSET PM821 has fifteen adjustable parameters, reached with the Confirm key. The table below gives the lowest and highest permitted value for each parameter and the value the unit leaves the factory with.
| Parameter | Min | Max | Unit | PM821-8 | PM821-16 |
|---|---|---|---|---|---|
| F1 — Pump stop pressure | 0.1 | value of F13 | bar | 3.0 | 3.0 |
| F2 — Pump start pressure | 0.1 | value of F1 | bar | 1.5 | 1.5 |
| F3 — Maximum pump current | 1.0 | 8 or 16 | A | 7.5 | 10.0 |
| F4 — Minimum pump current | 0 | value of F3 | A | 1.0 | 1.0 |
| F5 — Dry-run detection time | 0 | 600 | s | 20 | 20 |
| F6 — Retry interval | 0 | 600 | min | 20 | 20 |
| F7 — Start delay | 0 | 600 | s | 0 | 0 |
| F8 — Stop delay | 0 | 600 | s | 0 | 0 |
| F9 — Display brightness | 0 | 7 | — | 7 | 7 |
| F10 — Dry-run pressure threshold | 0 | value of F1 | bar | 1.0 | 1.0 |
| F11 — Soft-start time | 0.1 | 600 | s | 0.2 | 0.2 |
| F12 — Soft-stop time | 0.1 | 600 | s | 0.2 | 0.2 |
| F13 — Sensor full-scale pressure | 1 | 100 | bar | 20 | 20 |
| F14 — Pressure sensor calibration | 0 | 2000 | — | — | — |
| F15 — Pressure sensor offset | 0 | 1 | command | 1 | 1 |
F14 is calibrated individually for each unit at the factory and may differ from one unit to the next. Write it down and do not change it.
Faults and how to clear them
To clear a fault, press the Cancel key on the main screen.
E1 — Over current
The pump current has risen above the limit set in F3.
- Compare F3 with the current on the pump nameplate.
- Make sure the pump is not more powerful than the model rating.
- Clear the fault and start the pump again.
- If it returns, contact your dealer.
E2 — Load missing
The unit sees no pump current at all.
- Check the cable between the unit and the pump, and its terminals.
- Check the pump capacitor.
- Check the pump temperature; the thermal switch inside may have cut the current. Let it cool.
- Clear the fault, and contact your dealer if it returns.
E3 — Dry running
Water is not reaching the pump; the unit detected it from the drop in current.
- Make sure water reaches the pump inlet.
- Open the pump inlet valve fully.
- Bleed the pump.
- If there is water and the fault keeps returning, reduce F4 slightly.
This fault clears by itself once the water returns; the unit retries every F6 minutes.
If the output drives a contactor, the pump current does not pass through the unit. Set F4 to 0 so E3 is ignored and detect dry running by pressure (F10).
E4 — Low pressure
The pressure does not build up; the unit detected dry running from the pressure.
- Make sure water reaches the pump inlet.
- Check F10; it must be lower than the normal working pressure.
- Check where the sensor is fitted; it must sit after the check valve.
- Check the bypass valve — it may look closed but still leak.
This fault clears by itself once the water returns; the unit retries every F6 minutes.
E5 — Cycling error
This code is printed on the enclosure, but the manual for hardware A3.3 / software 4.0 does not document its cause or remedy.
E6 — Pressure sensor
The pressure sensor cable is broken or the sensor itself has failed.
- Check the green light on the back of the sensor. If it is off, the sensor or its cable is faulty.
- Inspect the sensor cable along its length.
- If the problem remains, replace the sensor.
E7 — Temperature sensor
The unit's internal temperature sensor has failed.
- Clear the fault. If it returns, the unit needs service; contact your dealer.
E8 — Over temperature
The temperature inside the unit has risen too high.
- Wait a few minutes for the unit to cool.
- Improve ventilation and keep it out of direct sunlight.
- If it returns, compare the pump power with the model rating.
This fault clears by itself once the unit has cooled.
Technical specifications
| Property | PM821-8 | PM821-16 | Unit |
|---|---|---|---|
| Maximum pump current | 8 | 16 | A |
| Maximum pump power | 1.5 | 3 | kW |
| Peak starting current | 10 | 30 | A |
| Supplied sensor pressure range | 0 – 20 | 0 – 20 | bar |
| Pressure sensor thread | G1/4 | G1/4 | female |
| Input voltage | 180 – 240 | 180 – 240 | V |
| Output voltage | — | — | equal to input |
| Unit's own consumption | < 5 | < 5 | W |
| Operating temperature | -15 – 55 | -15 – 55 | °C |
| Weight, boxed | 650 | 650 | g |
These figures come from the HYDROSET PM821 user manual (hardware A3.3, software 4.0). The manual covers PM821-8 and PM821-16 only, so no column is shown for PM821-25.
Warranty and after-sales service
- 2-year warranty — free replacement or repair for any defect in parts or manufacture.
- 5 years of after-sales service — parts, repair and technical support after the warranty period.
Warranty terms
- The warranty starts on the date of purchase. The invoice or the unit's serial label is the reference.
- The unit must have been installed and used according to this manual.
- In case of a defect in parts or manufacture, the unit is replaced or repaired free of charge.
What voids the warranty
- Opening or repairing the unit outside an authorised dealer
- Physical damage, impact, or water entering the unit
- Connection outside the 180 to 240 V range, or damage from lightning
- A defaced serial label
Other names for this device: smart pump controller · automatic pump switch · pump protector · electronic pressure switch · pressure controller
Last updated: