Taco 00-VR3 pump head assembly
Part: 00-VR3 head
Use for red 6-flash module faults or seized motors after the hydronic loop is filled and bled.
$120-$320
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Taco Variable Speed Pump Fault Codes — Quick Reference
Taco Comfort Solutions manufactures variable-speed ECM circulators including the 00-VR3, 007-VR, and VT2218 series. These pumps use LED status indicators and, on advanced models, a pushbutton-activated fault display. The Taco 00-VR3 is one of the most widely installed variable-speed circulators in North American hydronic heating systems.
| LED / Display | Model | Meaning | Quick Fix |
|---|---|---|---|
| Green solid | 00-VR3, 007-VR | Normal operation | None |
| Green flashing | 00-VR3 | Auto-adapt / performance mode active | Normal |
| Red solid | All VR series | Pump fault | Check power, blockage, temperature |
| Red 1 flash | 00-VR3 | Rotor blocked / locked | Manual rotation; bleed air |
| Red 2 flashes | 00-VR3 | Overvoltage | Check supply voltage |
| Red 3 flashes | 00-VR3 | Undervoltage | Check supply voltage |
| Red 4 flashes | 00-VR3 | Overtemperature | Check system temperature; check load |
| Red 5 flashes | 00-VR3 | Dry running detected | Fill and prime system |
| Red 6 flashes | 00-VR3 | Internal module fault | Replace pump or head assembly |
| Amber solid | 00-VR3 | Reduced-mode operation | System constraint — check valves/flow |
Most Common Faults
Red 1 Flash — Blocked Rotor
After sitting idle (seasonal shutdown, new system filling, or extended power outage), the 00-VR3’s impeller can seize due to mineral deposits or debris. Taco provides a manual bleed/priming procedure:
- Turn off power to the pump
- Locate the center bleed plug on the motor face — it has a slot for a flathead screwdriver
- Insert the screwdriver and rotate the shaft clockwise — it should move with some resistance
- Once freely spinning, reinsert the bleed plug
- Restore power — the pump should start
If the shaft is completely immovable (not just stiff), the motor has seized and the pump head assembly requires replacement.
Red 5 Flash — Dry Running
Dry running protection is active. The pump detects it is running without liquid surrounding the rotor. Check:
- All isolation valves in the circuit are open
- The system expansion tank is properly pressurized (residential systems: 12–15 PSI cold fill)
- Air has been bled from the system
- The pump body itself is submerged in liquid (pumps should have water in the casing before startup)
Red 4 Flash — Overtemperature
The pump motor temperature exceeded its protection limit. Taco 00-VR3 is rated for systems up to 210°F (99°C). In domestic hot water recirculation applications with abnormally hot water heater temperatures, this fault can occur. Also check for flow restriction — partially closed balancing valves can force the motor to work harder.
Amber LED — Reduced Mode
The amber solid LED on the 00-VR3 indicates the pump has entered reduced mode, where it runs at a lower speed than optimal. This often happens when the system pressure differential is very low (indicating low flow). Check for closed zone valves, air-locked circuits, or improperly set balancing valves.
00-VR3 Operating Modes
The Taco 00-VR3 has four operating modes selectable via the front button:
| Mode | Description |
|---|---|
| Auto-Adapt | Learns the system and adjusts automatically (recommended) |
| Delta-P (proportional) | Adjusts head pressure proportionally to flow |
| Delta-P (constant) | Maintains constant pressure differential |
| Fixed Speed | Three fixed speed settings (manual override) |
Need Replacement Parts?
Before ordering, match the commercial equipment part to the model number, electrical rating, and failure symptom. Check current prices on Amazon - prices and availability change frequently.
Most 00-VR3 faults are resolved by ensuring the system is properly filled and the pump is in Auto-Adapt mode.
When to Call a Pro
Red 6 flash (internal module fault) and any fault that persists after system has been properly filled and bled indicates the pump head assembly needs replacement. Taco offers the VR3 head assembly as a separate part — it replaces the motor/electronics while retaining the installed valve body.