The ALPHA Series includes all ECM‑based hydronic and domestic hot‑water circulators. These pumps use permanent‑magnet motors, advanced control modes, and optimized performance curves to reduce energy use and improve system stability.
Included families: ALPHA 15‑58, ALPHA1 26‑99, ALPHA2 26‑99, ALPHA HWR, ALPHA Comfort System
Series Purpose
High‑efficiency ECM circulators for heating and domestic hot‑water recirculation, with internal or external control modes depending on model.
Shared Construction
- ECM permanent‑magnet motor
- Canned‑rotor design
- Water‑lubricated bearings
- Horizontal shaft
- Cast‑iron or potable‑approved stainless/bronze housings
- AUTOADAPT on most models
- Glycol compatibility up to 50%
ALPHA 15‑58 — ECM for Small/Medium Heating
Hydraulics: 19 ft head • 13.6 GPM
Control Modes:
- Constant pressure
- Proportional pressure
- Constant speed
- Constant flow
- AUTOADAPT
- Bluetooth (Grundfos GO)
Applications: Zone valves, TRVs, boiler pumps, indirect tanks
Not for: Potable water, large circuits
ALPHA1 26‑99 — ECM with 0–10 V External Control
Hydraulics: 42 ft head • 26 GPM
Control: External 0–10 VDC only
Behavior: Runs at full speed if signal absent
Applications: Boiler‑controlled systems, BMS integration
Not for: Standalone use, potable water, AUTOADAPT systems
ALPHA2 26‑99 — ECM for Large Heating Circuits
Hydraulics: 42 ft head • 26 GPM
Control Modes: Constant pressure • Proportional pressure • AUTOADAPT
Materials: Cast iron or stainless SU (potable)
Applications: TRVs, large zone‑valve manifolds, primary loops
Not for: Constant‑flow applications, Bluetooth control
ALPHA HWR — DHW Recirculation (Return Line)
Purpose: Domestic hot‑water recirculation with a dedicated return line.
Control Modes: Temperature • Timer • AUTOADAPT • Vacation • Disinfection
Materials: Stainless/bronze, potable‑approved
Applications: Residential DHW recirculation
Not for: Hydronic heating, tankless systems without flow review
ALPHA Comfort System — DHW Recirculation Without a Return Line
Purpose: Retrofit DHW recirculation using a bypass valve under the sink.
Control Modes: Temperature • Timer • AUTOADAPT • Vacation • Disinfection
Applications: Homes without return lines
Not for: Multi‑branch plumbing, heating systems
Best‑Fit Summary
- ALPHA 15‑58: Small/medium heating
- ALPHA1 26‑99: Boiler/BMS‑controlled systems
- ALPHA2 26‑99: Large heating circuits
- ALPHA HWR: DHW with return line
- ALPHA CS: DHW without return line
