Levalarms® Low Water Cut-Out and Level Switch Applications

Float Models see Levalarm® Gold


Our Tri-Magnet Mechanism provides the most secure switch action with zero effect from heat or vibration. Levalarm® Gold is the most dependable level switch for your boiler application.

Additional Options:

  1. Retropak Assembly with a probe and separate relay control to convert an existing Levalam from a float actuated device to a probe actuated device. This option uses the existing Levalarm body and piping.
  2. Change from EA100D to EA101D, EA100S to EA101S, and EA100SW to EA101SW, along with a relay control to replace an existing unit from a float actuated unit to a probe type actuation. This option uses the existing piping connections.


Retropak Cap Assembly for EA100 Levalarms®


EA-101D & EA-101S: Dual Fuctions on Boilers and Tanks

Recommended Control For Power Plants and Processing Facilities.  Pressures up to 1800 PSI (124 Bar)

Pressure rating determined by probe selection (T probes = 450 PSI (30 Bar), V Probes = 1000 PSI (69 Bar), Z Probes = 1800 PSI (124 Bar))

compact design, versatile operation


levelarm ea101


Series EA-101 models provide reliable and instant response.  Probes respond to the rise and fall of water at predetermined points, to actuate a variety of controls.  Each Levalarm monitors up to 3-inch level variation.  Multiple units, in series, extend the monitoring range.  Use almost anywhere on boiler water applications.


One Probe/One Relay: High Alarm – Low Alarm – Fuel Cut-Out (Low Alarm & Fuel Cut-Out At Same Level).

Two Probes/One Relay: On And Off Pump Control Within 3-Inch Level Variation.

Two Probes/Two Relays: Dual Fuel Cut-Out (Low Alarm & Fuel Cut-Out On Different Levels).

Clark-Reliance Relays Improve Reliability, Offer Installation Ease and Economy

  • Each relay module is independently fuse protected.
  • Plug-in relays are removed by hand, no tools required.
  • Relays supply low voltage (12 VAC) to Probes.
  • Relays enhance sensitivity for extremely low water-conductivity applications, to 1 MicroMho.
  • Relays improve switch contact reliability for low load applications such as computer interface, recorders.
  • Relays use integral LED indicators to verify status.
  • Relays will retrofit existing system installations.

relay levalarm

Interwiring Diagram, Control Unit Relay

Typical Relay, Single Level Service

Direct Mode Operation (Standard)  When water level rises to Terminal 3 Probe, water completes circuit.  Circuit signals Relay to change state of load contacts, activating Alarm or other equipment, while illuminating integral LED.  Relay is energized until water drops below Probe to break circuit, turning off Alarm and LED.

Inverse Mode Operation (Optional) Upon powering Supply Terminals 1 and 2, Relay energizes (LED on).  When water rises to Terminal 3 Probe, Probe signals Relay to de-energize (LED off).  Relay remains de-energized until water drops below Probe.  Even during momentary power failures, Relay remains in “safe” mode in Low Level applications.  Specify inverse mode, when required.

Example Interwiring of Single Relay Control
Unit with Optional Vibratory (350N) and Holding Switch (HS-1) For Low Level Service

example interwiring


Fuel Cut-Out Probe Bypass

modle Hs1

During probe column or Levalarm blow-down, the Holding Switch provides a bypass around the fuel cut-out relay.  This simple switch maintains relay circuit continuity momentarily, while being held in the bypass position during blowdown.  The Holding Switch also provides an indicator light to verify that the fuel cut-out relay is functioning properly.  The switch can be installed to operate with probe-type Levalarms on boilers.  Also available without indicator light (Model HSO).

Audible, Visual Alarms

visual alarms

Audible or visual alarms are available for all Levalarm applications.  The vibratory horn has a decibel rating of 100 DB at 10ft. and comes in standard model (350N) or weatherproof model (350W).  Visual alarms come in Normal/Danger and High/Normal/Low models.  Specify supply voltage, when ordering.

(*) Add “W” suffix to model for socket-weld connections



Brochure: EA100 Gold

Drawings: Levalarm® Gold Drawings

EA101S Levalarm

EA101D Levelarm

IOM: EA100 Gold Installation, Operation and Maintenance Instruction Manual

EA101D and EA101S Levalarm Installation, Operation and Maintenance Instruction Manual