H2O Pitless Unit Installation Guide

About the H2O Unit

PCM Galvanized Steel | Professional Installation

Complete Well Control. Right at the Well.

The Merrill H2O unit brings pump controls, piping connections, and an optional pressure tank into one compact system. Less wiring, faster installation, and easier maintenance—all with weather-protected controls and convenient top access.

Faster Installation. Easier Service. At Well Control.

Merrill H2O PCM galvanized steel pitless unit showing the internal pressure tank
H2O Unit (PCM Model)
VFD mounted on the H2O pitless unit control mounting plate
VFD Mounting Plate

Before You Start

Installation Application

Confirm casing size and bury depth. Verify the H2O unit has the correct well casing connection.

Components Used

Pitless unit, piping and pump; surge tank and transducer; pull strap; watertight cap. Have lifting equipment and electrical materials ready.

Preparation

Inspect and lubricate the pitless adapter O-ring, slides and tank connection before seating the unit.

Three-Step Installation

  1. Install Pitless Unit and Pump

    Installer connecting the H2O pitless unit to the well casing
    • Install the pitless unit on the well casing.
    • Connect the pump as you normally would.
    • Lubricate the pitless adapter, including the O-ring and slides.

  2. Lower Tank and Transducer

    Installers lowering the surge tank and transducer with the pull strap
    • Lower the surge tank and transducer with the pull strap.
    • The tank nut should engage the connecting nipple when properly aligned and lubricated.

  3. Complete Wiring and Install Cap

    H2O watertight cap and aluminum VFD mounting plate
    • Complete all required wiring.
    • Mount the VFD to the aluminum plate using the included screws.
    • Install the watertight cap.

Installation Complete

  • Wiring complete
  • VFD setup
  • Watertight cap installed