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Fröling P4 Automatic Wood Pellet Boiler

High Efficiency EPA Certified Commercial Pellet Boiler

The P4 automatic wood pellet boilr by Fröling is EPA Certified!p4 wood pellet boiler

The award-winning Fröling P4 automatic wood pellet boiler is one of the world’s most advanced wood pellet boilers with lambda control. The best in class Fröling P4 wood pellet boiler has an award-winning, 10-year track record in the United States. Fröling P4 wood pellet boilers provide a convenient, safe and environmentally responsible way to heat space and hot water with wood pellets. P4 owners are assured of unusually high heating efficiency, low heating costs, and use of an abundant, locally available, renewable fuel. With its ingenious, fully automated operation, this wood pellet boiler is amazingly easy to use. The P4 wood pellet boiler provides the convenience of gas or oil central heat with lower fuel bills. The boiler is covered by a 5-year limited warranty.

Available Models

• Fröling P4 Wood Pellet Boiler 48/60- 163,780-200,000 Btu/hr
• Fröling P4 Wood Pellet Boiler 80/100- 273,000-341,000 Btu/hr

New Hampshire State Rebates (NH Public Utilities Commission)


• A rebate payment of 40% of the system and installation cost, up to a maximum of $10,000.
Minimum three-ton capacity for pellet fuel storage.
Must be a resident of New Hampshire and their primary residence.

Link to Program Details


A rebate payment of 30% of the system and installation cost, up to a maximum of $50,000.
Minimum three-ton capacity for pellet fuel storage.
• An additional rebate payment of 30% for the installation of a thermal storage tank, up to a maximum of $5,000.

Link to Program Details

Vermont Rebate Program (Efficiency Vermont and Vermont Renewable Energy Resource Center)

Efficiency Vermont

• $3,000 cashback after purchase.
• Rebates are for new, high-efficiency wood pellet boilers and furnaces that are installed as primary central heating systems.
• Replacement of natural gas-fired heating systems is not eligible.
• Systems must be classified as indoor systems and installed inside.
• Systems must be wood pellet only.
• Systems must have at least one-week fuel-storage and automated on/off and fuel feed.


Commercial buildings over 5000 sq. ft. may be eligible for funding of up to $1.25 per sq. ft. Please contact Renewable Energy Vermont for more details.

Link to Program Details

Vermont Renewable Energy Resource Center

$3,000 per installed pellet boiler.
Fuel storage capacity such that the system may continuously operate for a period of at least 14 days under peak load conditions.
Automated fuel feed from a bulk storage container/area to the burn chamber in an integrated path.
Automated on/off fuel feed control based on a demand for heat.
Bulk fuel storage container systems must be able to receive automated bulk delivery of pellets.
Customers are eligible for a $500 Pellet Storage Upgrade Adder for pellet storage systems that have at least 20 days of storage under peak load conditions.
Residential and commercial installations qualify.

Link to Program Details

Massachusetts (Massachusetts Clean Energy Center)

• Mass save HEAT Loan - 0% for 7 years; up to $25,000.
Alternative Energy Credits - The amount varies.

Link to Program Details

Massachusetts Renewable Energy Credits

New York (New York State Energy Research and Development Administration)

Residential Small Commercial Pellet Boiler Incentives

Incentives are 45% of installed costs based on system size:

Boiler Size (kW) Boiler Size (Btu/hr) Maximum Incentive
> 25 86,000 $10,000
35 120,000 $16,000
50 171,000 $23,000
88 300,000 $36,000

• An additional $5,000 for documented recycling (removal and destruction) of old outdoor or indoor wood boiler, or $2,500 for recycling a whole house wood furnace is also available.
• Incentives are available on a first-come, first-served basis.
• You may qualify for a Green Jobs - Green New York Smart Energy Loan to help pay for eligible project costs.
• Pellets must be stored outside of the building as outlined in the Program Manual.
• System Performance Requirements:

System Measures Levels
Thermal Efficiency 85%
Particulate Emissions less than 0.080 lb/mmBtu
Carbon Monoxide (CO) Emissions less than 270 ppm at 7% O2

Link to Program Details

Large Commercial Pellet Boiler Incentives

• Base award of 40% (up to $200,000 for units with output over 88kW (300,000 BTU/H).
• The incentive is for 45% of installed costs, with a cap of $270,000 for tandem pellet boilers with output over 300 MBtu/h (88kW).

System Type Incentive Maximum Incentive per Facility
Pellet Boiler
Output over 300 MBtu/hr (88kW)
40% of Total Installed Cost $200,000
Tandem Pellet Boilers
Output over 300 Mbtu/hr (88kW)
45% of Total Installed Cost $270,000

Link to Program Details

Advanced Cord Wood Boiler Incentives

Incentives are available for advanced cordwood boiler heating systems with full thermal storage for installations in the residential and small commercial sectors.
The installation must include full thermal storage as outlined in the Program Manual.
Total up to $10,000, calculated as 25% installed cost up to $5,000 per unit.
$5,000 for documented recycling (removal and destruction) of old outdoor or indoor wood boiler.
$2,500 for recycling whole house wood furnace.
Up to $5,000 per installed unit is available for customers with existing oil heat or propane.
Incentives are available on a first-come, first-served basis, and will only be reserved for customers once an application has been approved by NYSERDA

Link to Program Details

Maine (Efficiency Maine)

• 33% up to $3,000 towards equipment and installation.
• Eligible 1 to 4 unit residential buildings serving as a principal residence for occupants, new or retrofit.
• The system must include a bulk fill system that would provide continuous heat without human intervention for 2 weeks (estimated at 1 ton • pellet capacity) or has a minimum 500-pound capacity fill bin and a permanently installed back-up heating system (propane, oil, natural gas) that automatically switches fuel sources and provides continuous central heat to the home using the same thermostatic control and heating distribution system as the pellet boiler if the biomass heating system runs out of pellets.
P4 pellet boiler Cross Section

Commercial Ready

The Fröling P4 automatic wood pellet boiler with its fully automated operation can replace or supplement an oil or gas boiler in larger homes and commercial, industrial, or institutional buildings. Two sizes with Btu/hr. ranges between 163,780-341,000 with the capability to cascade up to four boilers together. Self-cleaning features and large removable ash bins mean low maintenance. The Fröling P4 100 wood pellet boiler is uniquely sized at 340,000 Btu/hr.  From single boiler installations to four boilers in a cascade, the P4 100 has a proven track record as an economical, durable, high-efficiency performer.  Please visit our blog to see many examples of commercial/institutional P4 wood pellet boiler installations in the United States.

The Fröling P4 Model 80/100 is ASME certified. ASME logo

Fröling P4 Information Video

Learn More - Downloadable Brochures

P4 Wood Pellet Boiler Brochure

Fröling P4 Brochure - file size 3 Mb

P4 Wood Pellet Boiler Planning Guide

Pellet Planning Guide - file size 4 Mb

P4 Wood Pellet Boiler Plumbing Schematics

Plumbing Guide - file size 2 Mb

P4 Wood Pellet Boiler Advanced Features

P4 Advantages - file size 861 Kb

Are you stoked

Are You Stoked? - file size 91 Kb

Learn More - Videos

p4 pellet boiler fan

Speed Regulated Draft Fan and Lambda Control

A speed regulated fan combined with oxygen and temperature based exhaust sensors allow Fröling wood pellet boilers to modulate output while remaining clean and efficient. The boiler can react to changing pellet fuel (harder/softer, more/less pitch, small/large pellets) while still remaining clean. The use of oxygen control is less common, but it is the best way to ensure the cleanest burn possible. Standard large touch screens enable internet connectivity and the ability to view multiple functions at a single glance. Fröling controls track fuel use, maintenance, and the function of all electric components.

p4 pellet boiler touch screen
p4 pellet boiler combustion

Automatic Ignition

All Fröling P4 Wood Pellet boilers have automatic ignition using a hot air gun that ignites the fuel quickly and effectively.

p4 pellet boiler ignition

Easy to Clean

Fröling wood pellet boilers self-clean the combustion grate and heat exchanger so that combustion is safe, clean, and controlled while extracting as much heat as is possible from your valuable fuel. The innovative three-pass design allows complete combustion, ensuring low emissions. Ash is collected automatically into two large ash containers, which can be emptied easily. Our average boiler owner only empties the ash box 3-5 times per year depending on the amount of fuel used.

p4 pellet boiler heat exchanger
p4 pellet boiler pellet feed

Industry Leading Safety Concepts

P4 wood pellet boilers are inherently safe due to combustion zones being surrounded by water. Because regular use never requires access to combustion zones there is no possibility for embers or fire to escape. Fröling takes the safety concept to new levels by not only using hollow drop tubes to deliver fuel, but they also add industry-leading double safety gates to isolate fuel storage from the combustion zone. It is impossible for both gates to be open during normal operation. The ingenious mechanical design coupled with advanced software ensures during self-testing that all components are ready before ignition is allowed.

p4 pellet boiler slide valve
froling connect
froling connect


Fröling Connect software allows free remote monitoring and control from web enabled devices. You can read and modify the main status information and settings easily and conveniently on-line. It is also possible to store historic operating information and receive warnings such as when the ash box is full. It allows the owner of the heating system to enable additional users, for example a family member, neighbor, or service technician. Once the boiler is connected to the internet, the system can be accessed 24/7 from everywhere using a smartphone, tablet, or PC with web browser.

froling connect

Pellet Storage Integration-several options available

  1. Universal System - one or three suction probes uniformly provide complete emptying of the storage room.
  2. Suction Screw System - ideal for rectangular rooms with front end removal.
  3. Bag Silo - pre-manufactured, flexible, simple and easy to assemble.
  4. External Silo -  ideal for commercial or for use when there is inadequate interior space.
  5. The Cube - a cost-effective solution for small fuel requirements.

Optional Pellet Deduster

Project Summaries

Here are two working P4 Wood Pellet Boiler Project Summaries. For more project summary examples on pellet, wood chip, and cordwood boilers please click here.

Tarm Biomass Project Summary 2
Tarm Biomass Project Summary 1

Quality, Safety, and Performance

The Froling P4 Wood Pellet boiler has won many international quality awards in Europe and the USA.


The Blue Angel

Plus X Award-International


Innovation Award at Bois Energie-France

New Product of the Show Award-Ireland

P4 Pellet Boiler Features

• EPA Certified
• Safety Tested and Listed
• For Commercial Use
• Fully Automatic
• Bulk Fuel Ready

• Fully Factory Assembled
• Pneumatic Pellet Feed
• Lambda Controlled for Optimal Combustion
• Dual Safety Gates
• Cascade Control Available for Multiple Boilers

• Automatic Heat Exchange Cleaning
• Integrated Storage Tank Control
• Includes Solar Thermal Control
• Exhaust Temperatures Under 350 F
• Ash Boxes with Auger for Long Ash Removal Times

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