Series 4FH

Series 4FH

The Series 4FH matches burner to boiler, providing a fuel efficient low-maintenance package. It takes maximum advantage of long-term energy and maintenance efficiencies.

The Versatile Boiler
The Burnham Commercial 4FH forced-draft steel firebox generator is a consistent sales leader in the heating industry, for reasons that make solid sense.

Design Firetube
Heat Exchanger 3 Pass
Standard Design Pressure 15 psi
Standard Design Pressure 30 psi/60 psi
Burner Customer Preference
Fuel Gas/Oil/Propane
Venting Forced Draft
Heating Surface- Sq Ft 5.0
Low Pressure Water Coil Yes
DOE/AHRI Status Certified


  • Compact, Efficient Three-Pass Firebox Design
  • No Tall or Costly Stack Required
  • Forced-Draft Firing with Oil (No. 2,4,5 or 6), Gas, or Combination Gas/Oil
  • 15 PSI Steam, 30 or 60 PSI Water
  • Ample Firebox Assures Non-Critical Combustion, High Efficiency


  • Forced-Draft Firing with Oil (No. 2,4,5 or 6), Gas, or Combination Gas Oil
  • High Efficiency Three-Pass Design
  • Available for 15 PSI Steam and 30 or 60 PSI Water*
  • Factory Assembled
  • Ideal for Modular Applications When in a TightIinstallation Area
  • Easy to Clean and Maintain—Requiring No Special Tools, Materials or Skills
  • ASME Code Construction

4FH Saves on Installation
It is a compact boiler that fits where other designs of similar capacity cannot. Available for 15 PSI steam and 30 or 60 PSI water*, the 4FH can serve perfectly as the heart of almost any system. As it is forced-draft fired, no tall, expensive stack is required. And because it is a factory-assembled, packaged unit, expensive jobsite time and labor are reduced.

*60 PSI water boiler available in sizes 4FH-63 through 4FH-993.

4FH Saves in Operation
The furnace surrounds the flame with highly efficient waterbacked primary heat-absorbing surfaces. This large combustion chamber is easy to fire, accommodating many forced-draft burners without flame impingement or other critical firing problems. Forced-draft firing makes the 4FH inherently more efficient than boilers using outmoded atmospheric burners, and gives you a feature that atmospheric units cannot offer: the option of burning gas or oil. A dual-fired burner allows you to burn the more economical fuel or the most readily available fuel at the flip of a switch, and affords you leverage in negotiating fuel prices.

The 4FH is an economical heat source, whether used singly or in multiples. In fact, 4FHs with modulating burners may be sequenced to operate in a step-fired system more cost effectively than a large number of residential-sized boilers when ongoing maintenance costs are considered.

4FH Saves on Maintenance
The 4FH is easy to clean and maintain, requiring no special tools, materials, or skills. Opening the front flue door allows firetubes to be brushed out quickly unlike the watertubes used in some boilers, which can be virtually impossible to clean. There are no elaborate or expensive proprietary seals required to reclose the doors as with some boilers. And, as the 4FH is a wetback boiler, there is no delicate or expensive rear refractory to maintain as with some dryback boilers. You can be confident that your 4FH will perform efficiently and dependably, year after year.


Boiler: Three-pass boiler constructed and stamped in accordance with ASME Section IV of the ASME Code for 15-psig steam or 30- psig water on any size boiler or 60-psig water on sizes 4FW63 through 4FW993. They are the sealed forced draft firing design with skid base and floor insulation. The flue outlet is a top outlet on sizes 4F63 through 4F345 and a rear outlet on sizes 4F450 and larger. Optional outlets are available on all sizes. The boiler comes complete with a gas tight front flue cleanout door, rear observation port on sizes 4F63 through 4F345, or rear access door and observation port on sizes 4F450 and larger and lifting lugs on sizes 4F127 and larger. Optional access doors and lift lugs are available for all sizes.

Jacket: Rectangular type 1” fiberglass insulated jacket on sizes 4F63 through 4F345, 2” fiberglass insulated rectangular jacket on sizes 4F450 through 4F675 and 2” fiberglass wrap around jacket on sizes 4F827 and larger.

Steam Trim: The following trim is shop mounted and wired: MM157 combination pump control and LWCO with alarm contacts and quick opening blowoff valves, probe type manual reset auxiliary LWCO, L404F operating pressuretrol, L4079B manual reset high limit pressuretrol and appropriate firing rate control when required.

The following trim is shipped loose for field mounting: 4” steam pressure gauge (on models 4FL63 through 4F675), 6” steam pressure gauge (on models 4F827 and larger), ASME side outlet safety valve(s) and gauge glass set.

Water Trim: The following trim is shop mounted and wired: Probe type LWCO (on 30-psig models 4FW63 through 4FW675) or MM 63M manual reset LWCO with quick opening blowoff valve (on 30-psig models 4FW827 and larger) or probe type LWCO (on 60-psi models 4FW63 through 4FW675) or MM 150M manual reset LWCO with quick opening blowoff valve (on all 60-psi boilers on models 4FW827 and larger) L4006A operating aquastat, L4006E manual reset high limit aquastat and appropriate firing rate control when required.

The following trims are shipped loose for field mounting: 31/2” theraltimeter (on models 4FW63 through 4FW675) or 5” thermometer and 6” pressure/altitude gauge (on models 4FW827 and larger) and loose ASME side outlet relief valve(s).

Burner (mounted & wired): Burners available for gas, #2 oil, #4 oil, #5 oil, #6 oil, and combination gas/#2 oil, gas/#4 oil, gas/#5 oil, and gas/#6 oil. Refer to burner data sheets for details of burner equipment.