Pros, Join Our TradeMaster Program!
The 166 series HydroMixer provides a fixed temperature flow to low temperature secondary heating circuits (such as floor radiant panels), complete with onboard three-speed or variable-speed pump, thermostatic three-way mixing valve with built-in temperature sensor, check valve, supply and return temperature gauges, secondary circuit shut-off ball valves and pre-formed insulation shell. Versions are available with either the three-speed Grundfos UPS 15-58 pump or the variable-speed Alpha 25-55U pump.

The unit can be ordered with supply flow and pump on the right or left side, and the unit is field reversible to accommodate changing installation requirements. The adjustable differential pressure by-pass valve, code 519600 and wall bracket code 165001 are optional. The unit comes with male union connections which require separately purchased, 1" sweat or NPT, top outlet and bottom inlet fitting kits.

Thermostatic fixed temperature mixing unit with insulation. Grundfos UPS 15-58 three speed pump. Grundfos Alpha 25-55U pump. Temperature gauges. Shut-off ball valves. Male union connections (select top and bottom fitting sets below).
  • Max working pressure: 145 psi.
  • Adjustable range: 80 - 125°F.
  • Power supply: 115 V 50/60 Hz.
Hide Description
Connection Size:


Max Pressure (PSI):


Power Supply:


Temperature Range (F):

80°F to 125°F




Grundfos 15-58 3-Speed Pump


Product Review

Product Q&A

Add-on Item

This item is cost-prohibitive to ship on its own but is available to ship with orders over $200.

Why don't we show the price of this item?

We try to always offer you the lowest prices possible, but some manufacturers require that we only show these low prices once you take further action.

To see the price, simply add the item to your cart or sign in.