Thermal Solutions has designed the Evolution® high efficiency copper-finned boilers to meet the needs of today's commercial heating requirements.

The Evolution takes the very best of existing copper-finned boiler technology to the next level by incorporating a list of design features not found in competitors' products. Real-life serviceability, innovative heat exchanger design, clean and efficient advanced combustion, and unique timesaving controls are all combined in a compact, quick-connect package with efficiencies of up to 87%. The Evolution is truly a step above the rest.

Real-Life Serviceability
The Evolution is adaptable to virtually any installation. Rear connection ports and complete front and rear access to the unit's components and controls simplify side-by-side modular applications. When venting is a concern, the Evolution offers sealed (direct vent) and power vent options so the need to construct a costly chimney is eliminated. In addition, the easy setup and even easier maintenance make Evolution boilers ideal for either retrofit or new construction projects.

Innovative Heat Exchanger Design
Central to the Evolution's highly efficient operation is the design of its copper-tube heat exchanger. Not only does it efficiently maintain heat transfer, but the innovative gasketless header allows easy inspection, cleaning and individual tube replacement. The combustion chamber is also completely enclosed in a stainless steel compartment and features collection/evaporation components to effectively handle cold-start condensate. Combining these features, the Evolution offers state-of-the-art heat transfer properties while effectively dealing with start-up condensate.

Clean and Efficient Advanced Combustion
Designed to operate at up to 87% thermal efficiency with NOx ratings less than 10 ppm, the Evolution's noiseless ceramic radiant burner runs at minimal excess air levels creating highly efficient, trouble-free operation. The rugged, industrial-cast-aluminum blower and fan wheel are equipped with a replaceable combustion air filter (99% efficient to one micron) to create excellent combustion characteristics and even air distribution. There's no need for tricky pressurized compartments...the Evolution can even be operated with its jacket panels removed for easy inspection or maintenance.

Unique Timesaving Controls
Instead of using a series of relays, the Evolution utilizes state-of-the-art microprocessor flame safeguard controls to provide extensive diagnostic information including first-out fault annunciation using an LED diagnostic display. The proven spark-to-pilot ignition system ensures that the pilot is lit before allowing the main gas valve to open. The optional display unit, as shown at the left, can be easily incorporated to provide additional operational information and history.
Unit of Measure


MBH Input

N/A 1000 MBtu/hour

Elect. 1-Phase

N/A 120 208 230

Elect. 3-Phase

N/A 208 230 460


N/A No


N/A Yes


Dimensional Drawing for Evolution - High Efficiency Hot Water Boilers - On/Off and Modulating, Indoor, Storage Tanks/Skid

Ratings and Dimensional Data

Input: BTUH

N/A 1,000,000 Btu/hr

Output: BTUH

N/A 819,000 Btu/hr

Sq. Ft. per BHP

N/A 7.2 ft²

Width: "A"

N/A 28.25 in717.55 mm

Depth: "C"

N/A 30.25 in768.35 mm

Height: "B"

N/A 65.188 in1655.76 mm

Gas Connection: NPT

N/A 1-1/2 in

Water Connections: NPT

N/A 3 in

Air Inlet Connection

N/A 6 in152.4 mm

Vent Connection

N/A 6 in152.4 mm

Shipping Weight

N/A 1185 Pound

Ratings & Capacities


N/A 24.5 hp240 kW


N/A Natural Gas Propane

Input - High Fire

N/A 1,000,000 Btu/hr

Output - High Fire

N/A 819,000 Btu/hr

Inlet Gas Pressure (NG)

N/A 5 PSI Max. 7" W.C. Min.

Inlet Gas Pressure (LP)

N/A 2 PSI Max. 7" W.C. Min.

Operating Weight

N/A 1322 lb600 kg

Electrical Supply Options

Electrical Supply Options (Modulating)

N/A 120v/1ph/60hz - 7.5 Amps 208v/1ph/60hz - 6.6 Amps 208v/3ph/60hz - 6.0 Amps 230v/1ph/60hz - 6.4 Amps 230v/3ph/60hz - 6.0 Amps 460v/3ph/60hz - 3.0 Amps

ASME Design Data

ASME Design Data

N/A Max. 160 PSIG & 250ºF

Trim & Controls

Trim & Controls

N/A Blower Motor, 1-1/2 HP Combustion Air Switch Flame Safeguard High Temperature Limit High/Low Gas Press Switches LWCO Flow Switch Modulating Gas Valve Operating Control Pilot Gas Regulator Pilot Gas Valve Pilot/Leak Test Cocks Pressure & Temperature Gauge Relief Valve VFD

Double Block & Bleed (D.B.& B.) Gas Train Option

Double Block & Bleed (D.B.& B.) Gas Train Option

N/A (1) Motorized & (1) Solenoid Gas Valves N.O. Vent Valve

D.B.& B. W/ P.O.C. Gas Train Option

IRI W/ P.O.C. Gas Train Option

N/A (2) Motorized Gas Valves with proof of closure switches Flame Safeguard that recognizes proof of closure valves N.O. Vent Valve

Firing Modes

N/A Evolution boilers are available in Full Modulation. Full modulation is achieved using a VFD and an air-fuel ratio modulating control valve. The control valve is actuated by an air signal from the fan - as the fan varies so does the gas valve. It is truly a linkage-less system and allows for safe fuel-air combustion. The full modulation uses a digital operating controller for infinitely proportional firing. Full modulation is available in models 500-3000 MBH input.

The Evolution boiler is available as a single or multi phase electric input, both 50 and 60 hertz. With no requirement for step-down transformers, the Evolution package comes complete and ready for single point electrical connection.

Evolution® Outdoor Model

N/A A specially designed, fully UL-approved outdoor jacket enclosure allows outdoor placement and all-weather operation.

In a response to industry demand, the Evolution outdoor unit enters the scene with the same robust design as the superior indoor model. The Evolution outdoor boiler is also designed to operate with NOx ratings as low as 10 ppm. Manufactured in five sizes from 500,000 to 2,000,000 BTU, the outdoor unit is available in on/off and full modulation firing modes. It is also available in both single and three-phase voltages. The outdoor model occupies the same footprint as the indoor unit, and its specially designed, fully UL-approved outdoor jacket enclosure allows outdoor placement and all-weather operation with lockable panel.

Evolution High Efficiency Domestic Hot Water Heating

N/A Get advanced Evolution high-efficiency heating technology in a factory-assembled Packaged Water Heater System. Available in direct and indirect designs, each comes complete with storage tank, pump, and controls to serve as your single-source solution for domestic water heating needs.



  • Efficiencies up to 87%
  • Ultra-low NOx levels below 10 ppm; meets or exceeds the most stringent emission requirements in the United States
  • CO less than 50 ppm
  • Quiet operation (<50 dBA)
  • Maintenance-free ceramic radiant burner design
  • Gasketless header design; minimizes the potential for leaks
  • High quality copper-finned tubes extruded from solid copper piping; wall thickness is the best in the industry at 0.072"
  • Copper tubes are individually accessible for cleaning or inspection and replaceable to eliminate the need for whole heat exchanger replacement
  • Standard UL/FM/CSD-1 gas train; optional DB&B or IRI with POC gas train
  • Single-point electrical hook-up for all voltage options (120-208-230/1/60 and 208-230-480/3/60)
  • Multiple relief valve settings (30, 50, 60, 75, 100, 125 and 150 psig)
  • Gas pressures range from 4" wc up to 5 psig
  • Electric spark-to-pilot-ignition system
  • Aluminum non-sparking fan assembly
  • Inlet air filter 99% efficient to 1 micron
  • Non-proprietary parts
  • Jacket design lends itself to complete access to all components for easy serviceability
  • Quick-connect compact package; maximum footprint is 6 sq/ft
  • Sealed combustion or room air ready
  • Reduced stack sizes - multiple venting options: sealed, direct and conventional
  • Factory fire-test on every unit 



cUL US, {H} Listed