Description
The Grundfos 59896123 (UP 15-18 BUC5) is a Circulator Pump — Single Speed. Single-speed circulator for domestic heating systems. Maintenance-free permanently lubricated bearings. Nominal performance: 5.06US gpm at 8.803ft. Rated 115V, 1-Phase, 60 Hz. Applications include Residential hot water recirculation.
Genuine Grundfos Part
OEM component engineered and manufactured to Grundfos specifications. Maintains pump performance and warranty coverage.
Full Traceability
Genuine Grundfos parts carry manufacturer traceability from production through delivery. No counterfeit risk.
Authorized Source
PumpStop is an authorized Grundfos distributor. All parts are genuine — not aftermarket, not surplus.
Confirm Compatibility
Always verify part number against your pump model number and serial number before ordering. Contact PumpStop for parts identification assistance.
Technical Support Available
PumpStop technical team can identify correct parts from pump nameplate data, serial number, or model code. Call (781) 281-8905 or chat.
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Parts availability varies. Contact PumpStop to confirm stock, lead time, and pricing before placing an order.
| Model Number | 59896123 |
| Product Series | UP |
| Series Description | Circulator Pump — Single Speed |
| Voltage | 115V |
| Phase | 1-Phase |
| Frequency | 60 Hz |
| Motor Protection | Contact |
| Insulation Class | F |
| Nominal Flow | 5.06US gpm |
| Nominal Head | 8.803ft |
| Max Operating Pressure | 145.04psi |
| Max Fluid Temperature | 230°F |
| Max Ambient Temperature | 104°F |
| Nominal Pipe Bore | 1/2" SWEAT |
| Pipe Pressure Rating | PN 10 |
| Pipe Standard | 1/2" SWEAT |
| Impeller Material | Composite |
| Housing Material | Bronze |
| Approvals / Certifications | UL, CSA |
| Electrical | Verify supply voltage, phase, and frequency match nameplate before installation: 115V, 1-Phase, 60 Hz. |
| Temperature limits | Do not exceed max fluid temperature 230°F or max ambient temperature 104°F. Exceeding limits damages seals and motor insulation. |
| Dry running | Do not run dry. UP pumps use the pumped fluid to lubricate the shaft seal. Dry running destroys the seal within seconds. Install dry-run protection on all automatic installations. |
| Maintenance | Refer to the Grundfos Installation and Operating Manual (IOM) for correct installation, commissioning, and maintenance. Contact PumpStop for documentation. |
- Approvals
- UL, CSA
- Built-in motor protection
- CONTACT
- Capacitor size - run
- 10 µF/180 V
- Connection
- PN 10
- Current in speed 3
- 0.74 A
- Density
- 61.35 lb/ft³
- Frequency
- 60 Hz
- Gross weight
- 5.37 lb
- Housing
- Bronze
- Impeller
- Composite
- Insulation
- F
- Insulation class (IEC 85)
- F
- Length
- 5.31 in
- Liquid max temp
- 230°F
- Liquid temperature range
- 35.6 .. 230 °F
- Max flow
- 14.5 US gpm
- Max. power input
- 85 W
- Maximum ambient temperature
- 104 °F
- Maximum head
- 14.44 ft
- Maximum operating pressure
- 145.04 psi
- n rpm
- F
- Net weight
- 4.85 lb
- Number of poles
- 2
- Phase
- 1
- Pipe connection
- 1/2" Sweat
- Pressure rating for connection
- PN 10
- Pump housing
- Bronze
- Pumped liquid
- Water
- Rated flow
- 5.06 US gpm
- Rated head
- 8.803 ft
- Rated voltage
- 1 x 115 V
- Return valve
- Product name:UP 15-18 BUC5
- Selected liquid temperature
- 140 °F
- Terminal box position
- 9H
- Thermal protec
- Impedance protected
- Type of connection
- Smooth pipe
Dimensional Drawing
UPS, 3-SPEED TECHNOLOGY (Product brochure)
DBS, GRUNDFOS RESIDENTIAL BUILDINGS (Product brochure)
Get It All with Grundfos Plumbing, ONE PARTNER ALL the PUMPS (Product brochure)
UP Series circulators® (Installation and operating instructions)
Dielectric Isolation Valve (Installation and operating instructions)