Provide Operating Control with Automatic Limit Protection for Pressure Systems up to 300 PSI

Models have Snap-Acting Switching to Open or Close a Circuit on Pressure Rise

Have Adjustable Differentials

Ground Screw Terminal

15 Foot Lead Length is Used to Control Floor Temperatures of In-Floor Radiant Heating Application

Two-wire polarity-insensitive non-programmable network communicating thermostat

User buttons feature liquid crystal display as well as outdoor, indoor and floor temperature displays

Floor temperature sensing with minimum and maximum limits (when used with optional AQ12C20 Slab/Floor Sensor (sold separately))

Selectable temporary and permanent backlight

The PA404A is a Pressure Actuated High Limit, Safety Control for Steam Heating Boilers

It Breaks an Electrical Circuit to Shut Down the Burner if Steam Pressure Rises Above a Safe Level

The PA404B is Used with Suspension-Type Unit Heaters to Make the Fan Circuit When a Pressure Rise Indicates the Presence of Steam

Each Model Contains an SPST Micro Switch Snap Acting Switch

Sensitive Pressure-Actuated Diaphragm Expands or Contracts with Pressure Variations, Moving a Lever Mechanism Which Operates the Snap Switch

A Screw on Top of the Case Allows Set Point Adjustment without Removing the Cover

Differential is Adjusted by Means of a Dial Located Inside the Case

Simplify the wiring process

Easy to follow PC board and secure screw terminal layout eliminates problems caused by incorrect wiring

External indicator lights confirm operation sequence and diagnostic feedback

The unit includes two built-in 40 Volt Amp transformers, Extra fuses provided

This 3-Wire Thermostat Offers System Set-Up Capabilities with Simple, Easy-To-Use Menus

There is a Reduced Operating Mode which May be Used for Nighttime and Vacation Periods

With the Optional Floor Sensor this Thermostat Can Regulate Either the Floor or the Room Temperature or Both in that Case the Floor Sensor is Used as a Temperature Limiter, Either High or Low Limit

Thermostat May Also be Used to Control Relays and Other Low Voltage Controls

This Thermostat Uses Silent Operation Electronic Triac Output

Straight configurations can be installed onto radiators or within the system, for branch or main venting functions (multiple vents may be required for this type of installation)

Durable chrome-plated finish is both decorative and functional

all configurations are plated and are more resistant to moisture staining than unplated vents

Straight configurations can be installed onto radiators or within the system, for branch or main venting functions (multiple vents may be required for this type of installation)

Durable chrome-plated finish is both decorative and functional

all configurations are plated and are more resistant to moisture staining than unplated vents

Angle configurations are typically Installed at the top of a steam radiator, for the purpose of venting trapped air by means of steam displacement

Durable chrome-plated finish is both decorative and functional

all configurations are plated and are more resistant to moisture staining than unplated vents

The adjustable T-90A is capable of slow, medium or fast venting, to accommodate extreme variations in room temperatures, such as colder rooms with radiators located farthest from the boiler, to hotter rooms with radiators located closest to the boiler

No Clog Vent

Dirt and Debris Resistant

360 Degree Adjustable Collar Ring for Installation Flexibility

Stainless Steel Concentrator Which Eliminates Gurgling Noise

Bronze Body for Rigid Construction

Guarantees Fast Start up with Automatic Venting

Micro-Bubble Concentrator has Three Times the Impact Area of Other Products

Helps Prevent Corrosion of System Components

Improves System Efficiency

Made in USA

No Clog Vent

Dirt and Debris Resistant

360 Degree Adjustable Collar Ring for Installation Flexibility

Stainless Steel Concentrator Which Eliminates Gurgling Noise

Bronze Body for Rigid Construction

Guarantees Fast Start up with Automatic Venting

Micro-Bubble Concentrator has Three Times the Impact Area of Other Products

Helps Prevent Corrosion of System Components

Improves System Efficiency

Made in USA

No Clog Vent

Dirt and Debris Resistant

360 Degree Adjustable Collar Ring for Installation Flexibility

Stainless Steel Concentrator Which Eliminates Gurgling Noise

No Clog Vent

Dirt and Debris Resistant

360 Degree Adjustable Collar Ring for Installation Flexibility

Stainless Steel Concentrator Which Eliminates Gurgling Noise

Bronze Body for Rigid Construction

Guarantees Fast Start up with Automatic Venting

Micro-Bubble Concentrator has Three Times the Impact Area of Other Products

Helps Prevent Corrosion of System Components

Improves System Efficiency

Made in USA

No Clog Vent

Dirt and Debris Resistant

360 Degree Adjustable Collar Ring for Installation Flexibility

Stainless Steel Concentrator Which Eliminates Gurgling Noise

Bronze Body for Rigid Construction

Guarantees Fast Start up with Automatic Venting

Micro-Bubble Concentrator has Three Times the Impact Area of Other Products

Helps Prevent Corrosion of System Components

Improves System Efficiency

Made in USA

No Clog Vent

Dirt and Debris Resistant

360 Degree Adjustable Collar Ring for Installation Flexibility

Stainless Steel Concentrator Which Eliminates Gurgling Noise

Bronze Body for Rigid Construction

Guarantees Fast Start up with Automatic Venting

Micro-Bubble Concentrator has Three Times the Impact Area of Other Products

Helps Prevent Corrosion of System Components

Improves System Efficiency

Made in USA

Directional Flow Arrow for Correct Installation

Honeywell AP400 Series Air Purgers Provide Air and Water Separation in Hydronic Heating Systems, Improving Efficiency and Reducing Noise

Solidly Constructed of Cast Iron

The Air Purgers Feature Tappings for Expansion Tank and Auto Air Vent Mounting

Directional Flow Arrow for Correct Installation

Directional Flow Arrow for Correct Installation

Front Diagnostic Lights

Switchable Priority

Built-In Priority Protection

Simplified Wiring

Premium Sealed Relays

Compact Design

Fuse Protected

100 Percent Factory Tested

Isolated End Switch

Contractor Friendly PC Board Layout

Universal Thermostat Compatibility

24 Volt Power Output for Hard Wired Thermostats

Field Replaceable Transformer

Add-On Power Control Plug

Built-In Post Purge and Pump Exercise Functions

Switchable Primary Circulator Output

Two Boiler Contacts, Utilizes Full Functionality of Mod-Con Boilers

Expandable to 20 Zoning Panels

Interface with EXP Zone Valve Controls

UL Approved

Made in USA

Front Diagnostic Lights

Switchable Priority

Built-In Priority Protection

Simplified Wiring

Premium Sealed Relays

Compact Design

Fuse Protected

100 Percent Factory Tested

Isolated End Switch

Contractor Friendly PC Board Layout

Universal Thermostat Compatibility

24 Volt Power Output for Hard Wired Thermostats

Field Replaceable Transformer

UL Approved

Made in USA