Put Well
Control On Top.
The H2O Pitless Control Unit brings controls, tank, and service access together at the well for faster installs and easier service.
Installation
Service Access
Callbacks
“As far as I'm aware, all of the guys (contractors) that I talked with that installed them (H2O Control Pitless Units), 9 times out of 10, they like them.”
See Inside the H2O
A closer look at the internal components, controls, and service-ready design.
Internal Assembly
See how the main components are organized inside the unit.
Integrated Controls
Controls are positioned for easier access and service. Pressure switch options available.
Control Mounting Plate
Key control components are mounted together in one organized location.
Why Contractors Choose the H2O
Three simple reasons it makes the job easier.
Less
Installation Work
Key components and connections are already brought together in one unit.
Easier
Service
The internal assembly lifts from the top for quicker access.
Fewer
Callbacks
A cleaner, more organized setup means fewer potential problem points.
Model & Specifications
See options by casing size, bury depth, discharge size, tank size and casing material.
| Casing | Bury Depth | Discharge | Tank | Material |
|---|---|---|---|---|
| 4" | 3'–7' | 1", 1-1/4", 2" | No Tank / 2.1 / 4.5 / 6 Gal | Steel or PVC |
| 5" | Multiple | Multiple | Multiple | Steel or PVC |
| 6" | Multiple | Multiple | Multiple | Steel or PVC |
| 8" | Multiple | Multiple | Multiple | Steel or PVC |
Find the H2O unit that matches your casing and job requirements.
Available in multiple bury depths, discharge sizes and tank configurations.
How the H2O Works
Three steps that simplify installation and service.
Controls
at the Well
Pump control mounts at the top of the unit.
Pull Up
to Service
Internal assembly lifts out from the top for easier maintenance.
Everything
in One Place
Pressure tank and key connections are built into the system.
Full Access at the well. Installs Faster. Easier to Service.
Built for Smarter Well Control
The H2O Pitless Unit is engineered with features that make installation faster, operation smarter, and service easier.
Universal
Control
Mounting Plate
Mounts the pump control at the top of the well.
Internal
Pressure Tank
Keeps the tank protected inside the unit.
Built-In
Service
Pull Strap
Makes the internal assembly easier to remove.
Connections
Already
Included
Tappings for the transducer, relief valve and gauge reduce field work.
Built In. Protected. Ready to Service.
Common Questions
What Is an H2O Pitless Control Unit?
The Merrill H2O Pitless Control Unit combines your well controls, pressure tank and pump connection into one compact unit located at the top of the well.
- One unit
- Easier installation
- Easier service access
What Makes the H2O Different?
Traditional well systems have components in multiple locations. The Merrill H2O simplifies the system by bringing everything together at the well.
- Controls located at the well
- Fewer field connections
- No extra wiring run to the house
- Top-access design for easier service
One unit means less installation work and simpler maintenance.
Are In-Well Pressure Tanks and Controls a Good Idea?
Yes—when properly designed. An at-the-well system saves indoor space and keeps the pressure tank, pump controls and plumbing connections in one central location.
Is a Small Pressure Tank Enough?
It can be when paired with a constant-pressure or VFD well system. Tank size should always match the pump and control manufacturer’s recommendations.
Can the H2O Pitless Control Unit Freeze?
No, when installed correctly. The pitless adapter or discharge should be buried below the local frost line to protect against freezing.
Will the Pressure Tank Provide Water During a Power Outage?
Only a small amount. A pressure tank can supply limited stored water and is not intended to serve as a backup water source.
Can Water Sit Too Long in the Pressure Tank?
Yes, in low-usage systems. Proper sizing and regular water use help keep water circulating.
Should Well Pressure Drop When No Water Is Being Used?
No. A pressure drop with no water use may indicate a leak, faulty check valve or another system issue.
Bring the Well System Together at the Well.
Shop Merrill Pitless Units →The Merrill H2O combines the pressure tank, well controls and key plumbing connections into one compact at-the-well system designed for easier installation and simpler future service.