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Fröling P4
Automatic High Efficiency Residential/Commercial Wood Pellet Boiler

  • Fully Automatic-automatic filling, automatic lighting, automatic cleaning.
  • Super high efficiency 92% in European tests.
  • Uses wood pellets in bulk or from bag.
  • Includes solar thermal controls for easy integration.
  • Used with or without thermal storage (storage encouraged).
  • Stand alone boiler or add on to an existing system.
  • Cascade control system for systems requiring multiple boilers.
  • True 3 pass heat exchanger and automatic heat exchange cleaning provide maximum efficiency.
  • Integrated storage tank control.
  • Unique in industry dual safety gates.
  • Industrial quality construction.
  • Only remove ash every 300-500 hours of operation.Boiler Live Button


The award winning Fröling P4 Automatic Pellet Boiler. One of the world's most sophisticated pellet boilers and the only one in North America with Lambda control. The P4 provides the convenience of gas or oil central heat with annual fuel bills of ½ the cost!

The Fröling P4 Fully Automatic Pellet Boiler has the following features:

  • 85-87% overall efficiency
  • automatic ignition
  • automatic self-cleaning sliding grate in combustion area
  • super insulated and soundproofed for heat retention and quiet operation
  • built-in automatic fuel feed
  • virtually self-cleaning
  • programmable Lamdatronic control system
  • speed-regulated induced fan
  • 3-pass heat exchanger guarantees the highest possible ash seperation and efficiency
  • scalable-up to four (4) boilers can be cascaded together.


P4 Pellet
Component Unit 8 15 20 25 32 38 48 60 80 100
Rated Heat Output Btu/Hr 35,800 50,800 68,200 85,300 109,00 129,650 163,780 200,000 273,000  341,000
Heating Efficiency Range 10,500
Electrical Connection 240V / 60Hz fused 15A
Electrical Consumption W 96 123 110 110 110 110 120 120  120  120
Boiler Weight lbs 772 772 948 948 1168 1168 1676 1676  2425  2425
Water Contents Gals 18.5 18.5 21 21 33 33 45 45 74  74
Maximum boiler temperature setting F 176 176 176 176 176 176 176 176  190 190
Minimum boiler temperature setting 104 104 104 104 104 104 104 104  104 104
Boiler Test Pressure Psi 65 65 65 65 65 65 65 65  65  65
Permitted Fuel Wood Pellets 1/4" Diameter

P4 Advantages

Fröling P4 The Most Advanced Pellet Boiler Available


• The Fröling P4 pellet boiler is Lambda controlled, which means that it can adjust to differences in pellet density, moisture content, and pitch content to always burn cleanly.

• The Fröling P4 has one of the most advanced controllers. It has the ability to monitor all boiler functions and control buffer tanks, solar hot water, heating zones, stand-by boiler, and up to 4 cascaded P4 pellet boilers.

 • b_129_186_16777215_0___images_stories_migrated_productimages_3pass.jpgA true 3-pass heat exchanger for greater ash separation and efficiency. Some competitors state that they have a 3-pass design, but don’t have it. European tests show the P4 as being about 2-3% more efficient than the next closest US competitor.

• Direct connection to radiant floor or other low temperature applications is possible without return water temperature lift due to advanced design of the pressure vessel.

• Two-zone heat exchanger is one of Fröling’s numerous patents and pushes its efficiency to one of the highest in the industry.

b_200_144_16777215_0___images_stories_migrated_productimages_dropfeed.jpg• The Fröling P4 has a drop-feed combustion design. This provides the highest degree of safety. The combustion can be completely extinguished rapidly when necessary. Re-starts take place with a controlled fresh fuel bed.

• The Fröling P4 has a very robust grate and turbulator cleaning system.

• Precise control of the fuel feed rate means overall improved efficiency.



• Ash drawer design is efficient and mechanically simple, making break-down or unplanned service unlikely.

• Easy to maintain. Major components do not have to be removed to perform an annual maintenance.

b_250_122_16777215_0___images_stories_migrated_productimages_picture1.jpg• The Fröling P4 has two fuel safety gates. One or the other is always closed making it nearly impossible for hot embers to reach the fuel supply.

• The Fröling P4 performs a self-test  before each start and has automatic diagnostics to guarantee safe starting and safe operation. Everything from adequate combustion air to the presence of fire is confirmed.


• The Fröling P4 needs only one combustion blower. Some boilers have a combustion and an induction blower.

• The combustion blower is regulated by the boiler's controller to ensure the exact air quantity for optimum combustion.

• The Fröling P4 can be operated with sealed combustion, perfect for air tight buildings. The temperature of the incoming air is raised with an integrated pre-heating system, increasing the efficiency of the system.


b_165_163_16777215_0___images_stories_plugandplay.jpg• The compact design of the Fröling P4 comes fully assembled for easy set-up.

• If needed, the larger components can be easily removed for easier movement and positioning.


• Integrated vacuum system allows easy connection to bulk storage.b_200_164_16777215_0___images_stories_migrated_productimages_picture5.jpg

• Tarm Biomass and Fröling offer pellet storage options for nearly all possibilities from textile silos, to 3 auger systems.

• Pneumatic pick-ups are non-powered and operateflawlessly.


b_150_94_16777215_0___images_stories_migrated_productimages_picture30.jpg•The boiler system can be easily controlled from your living room with the room console. It is extremely easy to view all important values and status messages.

• With Fröling’s Visualization Software (which is installed on a computer or laptop), the boiler system can be monitored and adjusted via an Ethernet connection.



• At Tarm Biomass, we understand the benefits of integrating thermal storage with a pellet boiler. The Fröling P4 boiler control includes advanced buffer tank management. A pellet boiler operated with thermal storage will operate more efficiently and last longer.

• We have one of the best warranties in the market which includes a 20 year pro-rated warranty on the pressure vessel.


P4 Brochure 422 Kb file size

Product Datasheet 1.16 Mb file size

Plumbing Schematics 3.81 Mb file size

Pellet Planning Document 7.62 Mb file size

P4 Pellet Boiler Cascade Control 426 Kb file size

P4 Certificate of Efficiency 204 Kb file size


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P4 Pellet Boiler Accessories

P4 Pellet Boiler Suction Discharge Units

P4 Pellet Boiler Suction Silo Units

P4 Pellet Boiler Silo Discharge Units

Thermal Storage

NH Rebate Program

New Hampshire Residential Bulk-Fed Wood Pellet Boiler Rebate Program

Great News! The successful rebate progarm from last year is back. The program offers rebates of 30% of the system and installation cost, or $6,000, whichever is less, for New Hampshire residents who invest in high-efficiency (80% or greater), bulk-fuel fed indoor wood pellet central heating boilers that become operational, serving designed intent and installer-certified on or after May 1, 2012.

Pre-approval (step 1) is required to reserve your place in the funding queue. Once the boiler has been installed the applicant must submit the (step 2) application to receive the rebate.

This is a great opportunity to install a Fröling P4 Pellet Boiler in your home! For more information on the program please click here.

New Hampshire Rebate Program Faq Section

1. What kind of wood pellet-fueled systems are eligible for a rebate?
Bulk-fuel fed wood pellet central boilers and furnaces that meet certain storage, automation, emissions, and other technical specifications are eligible for a rebate under this program. All technical requirements for eligible systems are detailed in Step 1 of the application form.
What is the amount of the rebate?
The rebate amount is 30% of the system cost and installation, up to a maximum of $6,000, whichever is less.

2. How do I apply for a wood pellet rebate?
To apply for a rebate, you must first complete the Step 1 application form. A hard copy of the application, signed and notarized, must be submitted to the Commission. It is recommended that you work with a qualified installer in completing your application.
After you receive Step 1 pre-approval from the Commission, you will need to document that your installation is complete, meets the specifications outlined in the Terms and Conditions in Step 1, and is operational. The Step 2 application form outlines the information required in order for you to claim your rebate.

3. If I receive a rebate from this program, am I eligible to also receive other rebates?
You may be eligible for other rebates that apply to wood pellet heating systems. The New Hampshire Office of Energy and Planning provides additional information on federal, state, and local renewable energy resources. You may also visit and click on the state of New Hampshire for a full list of other available incentive and rebate programs.

4. If I receive a rebate, are there any tax implications?
If you receive a rebate from the Commission, you will receive an IRS Form 1099. The rebate may or may not be treated as taxable income by the IRS. This does not constitute tax advice, however, and you will need to consult your tax preparer for advice on federal tax treatment.

5. How long will it take the Commission to process my rebate application?
Depending on the initial amount of applications that the Commission receives, and the completeness of the application, it should take approximately two to four weeks for staff to process your applications.

6. I have installed a central heating system that utilizes wood pellets, but I don’t have a bulk-fed system. Will the rebate cover the costs to upgrade my system?
No, the rebate will only cover systems installed after April 14, 2010. Modifications to existing systems are not eligible to receive funding under this program.

7. How can I determine if a wood pellet heating system is right for me?
New Hampshire residents have the benefit of living in a heavily forested state, thus providing a local resource option for the production of wood pellet fuel. Wood pellet fuel is produced locally, and with established forest management, can provide a long-term solution to home heating needs without using fossil fuel-fired systems. There are many factors to consider, however, in making the decision to install a bulk-fuel fed capable wood pellet central heating system. These factors may include, naming only a few, upfront costs, ongoing fuel costs, maintenance requirements, or fuel delivery features. To learn more about wood pellet heating, the National Renewable Energy Laboratory website and the Department of Energy’s Energy Savers website both provide a good starting place to better inform your energy investment decision


4 Britton Lane, P.O. Box 285, Lyme, NH 03768 · Tel 800.782.9927