Always check your specific furnace model serial to confirm the parts compatibility before installation

and MGB series boiler sizes

it prevents thermal overload and maintains the integrity of the refrigeration cycle

The internal design eliminates close-fitting sliding parts in the water passages

An 11/32" nut driver or socket is the standard size for these external hex drives

Grundfos 595916 Pump 321894-706 Always check your specific furnaceThe Grundfos 595916 (Model UP15 10SU7P TLC) is a heavy duty, stainless steel hot water recirculating pump designed specifically for retrofit applications in residential systems lacking a dedicated return line. This 115V single phase circulator utilizes the existing cold water line to loop thermal energy back to the water heater, ensuring instant hot water delivery at the furthest fixture. As a veteran grade recirculation system, it features a 1 25 HP