FAQ
TL;DR: For Vaillant VC186/3-5 with VPAR-5, a Wilo-based service rotor/motor swap works; paid PLN 250, and “It is a four-speed pump.” [Elektroda, Qdlaty78, post #17718532]
Why it matters: This FAQ helps EcoTEC Plus owners fix noisy/jamming VPAR‑5 pumps and pick proven, compatible replacements.
Quick Facts
- Confirmed fit: WILO RS 25/60r motor-rotor worked in a VC186/3-5 EcoTEC Plus. [Elektroda, Qdlaty78, post #17721054]
- Typical cost: ~PLN 250 for a Wilo service motor/rotor; reuse the original Vaillant connector. [Elektroda, Qdlaty78, post #17718532]
- Wiring/stages: EcoTEC Pro = 3-wire, single-stage; EcoTEC Plus = 5-wire, two-stage switched by the board. [Elektroda, kz61, post #17712985]
- Mounting note: Grundfos has different screw spacing and Allen size; Wilo aligns better as a drop-in. [Elektroda, BrodowskiG, post #17710830]
- Budget stopgap (3‑wire only): Omnigena Omis 25‑60, 100 W, ~PLN 90 suggested as a temporary fix. [Elektroda, BUCKS, post #17713017]
What rotor/motor actually fits a Vaillant VPAR‑5 in a VC186/3‑5 EcoTEC Plus?
A user confirmed installing a WILO RS 25/60r motor‑rotor in this boiler. That shows the VPAR‑5 is Wilo‑compatible here. Match RS 25/60r when sourcing parts. This solves noise and jamming from a worn rotor. [Elektroda, Qdlaty78, post #17721054]
How much does the Wilo service motor/rotor cost, and what wiring change is needed?
One owner bought a complete rotor with Wilo coil for about PLN 250 from Hydroit. Move the original Vaillant connector onto the Wilo motor. Then the controller selects two speeds from the four-speed motor. This preserves the boiler’s staged control. [Elektroda, Qdlaty78, post #17718532]
Can I swap in a Grundfos instead of Wilo?
Avoid that for this application. Grundfos units have different screw spacing and a different Allen size, so they won’t align. “Buy a regular electronic wilo and you'll be fine.” Use Wilo to simplify mounting and service. [Elektroda, BrodowskiG, post #17710830]
What do 3‑wire vs 5‑wire pumps mean on Vaillant EcoTEC?
EcoTEC Pro uses a single‑stage pump with a 3‑wire cable. EcoTEC Plus uses a two‑stage pump with a 5‑wire cable. The Plus model’s control board switches stages electrically. Plan replacements according to your wiring and staging. [Elektroda, kz61, post #17712985]
What do the extra two wires on a 5‑wire VPAR‑5 actually do?
They carry board control for two fixed pump stages. The boiler selects the active gear via the menu. This keeps factory behavior and hydraulic balance. Preserve these control leads during any motor swap. [Elektroda, BUCKS, post #17713577]
How do I swap in the Wilo service motor and keep Vaillant control?
- Isolate power, drain if needed, and remove the VPAR‑5 motor‑rotor assembly.
- Move the original Vaillant connector harness onto the Wilo motor.
- Fit the Wilo motor, restore seals, and verify two speeds via the controller. [Elektroda, Qdlaty78, post #17718532]
My VPAR‑5 is noisy and sometimes jams—what’s the likely cause?
Impeller axial runout can reach about 5 mm. That creates loud operation and can jam the rotor. Replace the rotor or motor assembly to fix it. Inspect components for wear during removal. [Elektroda, Qdlaty78, post #17154455]
Can I run a standard 230 V pump and set speed manually instead?
Some setups support a conventional pump with a mechanical speed switch. Confirm the boiler does not throw control errors afterward. Older models allowed manual selection on the pump. Newer Plus boards expect stage control from the PCB. [Elektroda, BUCKS, post #17713577]
Will the boiler menu let me pick the pump speed?
On two-stage Plus models, the main board handles stage selection via the menu. Older units used manual switches on the pump body. The menu determines which of the two gears runs. Check menu behavior after a motor swap. [Elektroda, BUCKS, post #17713577]
Where can I buy a compatible service motor for VPAR‑5?
Hydroit listed a “silnik serwisowy do pompy Vaillant VPAR5 Wilo.” Availability can change, so confirm stock before ordering. Users reported contacting the store for details. Verify compatibility against your pump model. [Elektroda, phonex, post #17710806]
Should I leave the second gear disconnected during testing?
If unsure about control voltages, measure them first. Leave the second stage disconnected initially. Reconnect after validating correct signals. This reduces miswiring risk during commissioning. [Elektroda, BrodowskiG, post #17718550]
What happens if I skip boiler maintenance for years?
A nine‑year gap led to a failed main heat exchanger and a noisy, jamming pump. The owner linked this to skipped maintenance. Address pump wear promptly once noise appears. Replace worn rotors before damage escalates. [Elektroda, Qdlaty78, post #17154455]
Is Vaillant the manufacturer of the VPAR‑5 pump?
In this case, the installed motor matched a Wilo RS 25/60r. That indicates a Wilo‑based unit inside this Vaillant boiler. Source Wilo service parts when replacing the motor‑rotor. Confirm markings before purchase. [Elektroda, Qdlaty78, post #17721054]
Does the EcoTEC Plus use stage switching rather than variable modulation?
Yes. The Plus variant uses electric stage switching from the main board. It selects between two fixed pump stages. Choose replacements that accept stage inputs to keep control working. [Elektroda, kz61, post #17712985]
Is there a cheap temporary pump option for non‑regulated setups?
Yes. One user suggested the Omnigena Omis 25‑60 (100 W) for about PLN 90. Use it on simple 230 V, 3‑wire systems. Treat it as a stopgap near end‑of‑life. [Elektroda, BUCKS, post #17713017]
It is a four-speed pump, from which the original connection is removed and the one from the boiler pump is inserted. Two gears are then in operation, selected by the controller. T.
