Grundfos Alpha 15-55 HWR-D

Energy Efficient Circulation Pump

Develco has in close co-operation with Grundfos developed the Alpha 15-55 HWR-D system for American households. The energy-efficient Alpha circulation pump communicates wirelessly via Bluetooth with a temperature sensor and up to 10 push buttons. Develco has developed mechanics, electronics and embedded software for both temperature sensor, push buttons and repeater.

Due to changes in Californian legislation Grundfos needed to develop a water circulation pump system that only circulates hot water upon user request via push button. Legislation precisely dictates when the hot water is allowed to circulate based on live data of absolute temperature, temperature increase and time. These strict requirements demanded development of a temperature sensor with high precision, low thermal response time and fast communication. To minimize maintenance, an adaptive communication scheme has been used, because it reduces power consumption ensuring a battery life-time of more than 10 years on a single lithium AA battery. Wireless communication always raises the question: Is the range sufficient? This issue has been addressed in the HWR-D system by simultaneously developing a discreet repeater that can be placed in problematic locations without installation or configuration.

With Alpha 15-55 HWR-D Grundfos has developed a sustainable pump that saves thousands of liters of water and reduces energy consumption in private households in the USA. The user interface on the pump is simple and intuitive, and the system is “self-healing”, so it is easy to install and requires no maintenance,” says Develco’s Project Manager Erik Refsgaard. “Develco has been responsible for the entire development process including radio and security approvals for use in the USA and worked closely together with Grundfos NPI department to put the system’s components into production,” continues Erik Refsgaard.

Grundfos Alpha 15-55 HWR-D


  • Bluetooth Low Energy BLE 4.2
  • Meets California Energy Commission Title 24
  • Temperature sensor with a battery life-time of +10 years and a fast response time with BLE
  • Temperatur sensor precision of +/- 0,1⁰F with a very short time constant achieved by a unique mechanical design
  • Radio and safety approvals for use in the USA


“Develco has played a major role from the very beginning in the development of the HWR-D system for the USA right from elaboration of requirements specification to development of interface on the pump, temperature sensor, push button and repeater and handing over to production at Grundfos. I would like to give a great cadeau to Develco’s project management and the good spirit in the co-operation. Develco’s development team has been very proactive, serious and constructive in solving small issues during the development. Develco has taken responsibility throughout the development process and contributed significantly so that Alpha 15-55 HWR-D functions and has been introduced in the American market,” explains Jakob Fly Hansen, Project Manager in Product Development at Grundfos.