• Radiant Heating
• Hydronic Space Heating
• Snow Melting
Firing Mode
Models 42 & 66 – Single-stage firing
Models 90-180 – 2-stage firing
Non-Condensing
Operates at 105 °F return water temperature
without condensing – perfect for the low-
temperature needs of radiant floor and snow
melting systems
Built-In Pump and Bypass
Offers maximum application flexibility
Honeywell IID Ignition
Standard S8600 IID eliminates off-cycle fuel
consumption; Standing pilot available on Models
90-180
“Spark-To-Hood” Pilot
Eliminates erratic pilot ignition and lockout
Motorized Vent Damper
Prevents heat loss during off-cycles
Non-Ferrous Waterways Option
All bronze pump and fittings and glass-lined
headers eliminate boiler oxygen permeation
problems associated with non-barrier radiant
tubing
Outstanding Warranty
One-year parts and service warranty against
defects
RESIDENTIALS
Inputs from
42,000
thru
180,000
BTUH
