Grundfos - AQUASTAT KIT 3/4" CLIP 85-105F Thermostatic Control (85F-105F)

The Grundfos Aquastat Kit 3/4" Clip-On Thermostatic Control (MPN 595444) is a temperature-controlled accessory designed for Grundfos UP Series single-speed hot water recirculation pumps. This clip-on aquastat mounts directly to 3/4-inch copper piping (7/8-inch outside diameter) and automatically starts the circulator when pipe temperature drops to approximately 85°F and stops it at approximately 105°F. By operating the pump only when needed, it reduces energy consumption, minimizes heat loss, and extends pump life. Ideal for residential domestic hot water recirculation systems, the kit installs quickly without cutting into the plumbing system.

Cross References

1. Grundfos — 595444
2. Grundfos — 00595444
3. Grundfos — AQS34 (distributor designation for the same 3/4" aquastat kit)

Usage

The Grundfos Aquastat Kit is installed by clipping directly onto the hot water return pipe of a domestic hot water recirculation system. It senses the pipe surface temperature and automatically controls a compatible Grundfos UP circulator. The control closes its contacts and starts the pump when the pipe temperature falls to approximately 85°F, then opens the circuit and stops the pump once the temperature reaches approximately 105°F. This automatic operation reduces unnecessary pump run time, saves energy, and helps maintain fast hot water delivery throughout the plumbing system.