The Grundfos Pumps Corp. Mixi-Mizer radiant floor heating pump improves control and energy use in primary/secondary piping configurations. The Mixi-Mizer injection pump proportions and injects water in exact quantities from the primary loop to the secondary loop. The Mixi-Mizer features an integrated pump and indoor/outdoor controller, boiler and system/concrete slab protection from controlled water temperature, a spring check valve and warm weather shut down.