Class 5 wood-fired boiler with 7 Flamme Verte stars

Class 5 wood-fired boiler with 7 Flamme Verte stars


Very high performance wood boilers
Power ratings of 15, 20, 25, 30 and 40kW
Efficiency greater than 91%.
Class 5 according to NF EN 303-5
Complies with 7* Flamme Verte requirements
Installation with or without accumulator tank depending on the case

Table of Contents

GFI: combining environmental protection and performance
GFI: comfortable functionning
Models and accessories


GFI: combining environmental protection and performance

PERGE: a reference on wood boilers the market

With more than 70,000 homes heated with wood boilers since 1974, PERGE is a real reference on the French wood boiler market.

 PERGE GFI wood boilers meet the requirements of the EN 303-5 class 5 standard and the 7-star Flamme Verte standard, with useful yields of over 90%. Their installation with one or more buffer tanks, combined with climate control, gives them an unequalled level of performance in terms of efficiency, autonomy and heating comfort.

High efficiency, energy savings and environmental protection

The quality of the combustion is constantly analysed by an oxygen sensor (lambda sensor). This allows the flow rate and distribution of primary and secondary air to be continuously adjusted. The combustion efficiency of the boiler is thus optimised during the entire combustion process. In addition, the controlled combustion hygiene ensures low emissions of pollutants, regardless of the type of wood burned, and helps to protect our environment.


GFI: Comfortable functionning

Easy to load

PERGE GFI boilers have an oblique loading door at the top which gives full access to the firebox and allows easy loading of the entire volume of the combustion chamber.

The 15 and 20 kW models use 35 cm logs.

The 25, 30 and 40 kW models use 50 cm logs.

With a hydro-accumulator tank for more autonomy

The installation of PERGE GFI boilers with a buffer tank and a recycling kit allows the surplus energy to be stored during combustion and released on demand. In the off-season, when heating demand is low, the buffer tank provides maximum benefit, allowing for a significant autonomy of one day or more.

The large volume of the shop allows a 1,000 litre tank to be heated to 90° in a single load of wood with a 20 kW boiler.

With a small buffer volume, no recycling kit

The PERGE GFI boilers are equipped with an anti-corrosion protection device, so that a recycling kit is not required. In addition, the control system allows the boiler to be operated at lower outputs during the off-season, or even to install a smaller buffer tank, which means financial savings and space saving.

Fire holding

PERGE GFI boilers are equipped with a mechanical low fuel level detection device. When this is detected, the boiler switches from a combustion phase to a fire-holding phase, and remains for several hours waiting for refuelling. After this, a relighting is necessary.


Models and accessories


GFI 15  15 kW
GFI 20 20 kW
GFI 25  25 kW
GFI 30

30 kW

GFI 40  40 kW

- Combustion control by oxygen sensor with action on the flow rate and distribution of primary and secondary air. (lambda sensor)
- Refractory ceramic post-combustion furnace.
- Factory fitted quench coil (allowing operation with a closed expansion vessel under nitrogen pressure).
- Factory fitted combustion control with touch screen control.
- Additional climate control can be fitted to control up to 2 heating circuits and domestic hot water, as well as solar heating or a boiler backup.
- Other equipment: heating tool, factory fitted reinforced insulation jackets
- Flue diameter: 150 mm.
- Maximum log length: 35 to 50 cm (depending on model)

Price examples

GFI 20

GFI 20

Very high performance wood boiler with a power of 20 kW
Class 5 boiler according to EN303-5 standard
Delivered with factory fitted quench coil.
Price excluding taxes
8.350 € HT

Why choose wood ?

An energy that is contributing in the fight against global warming

Wood combustion does not contribute to CO2 emissions as it is a balanced process with CO2 absorption during wood growth.

An energy that is contributing to our independance

Forest covers a large area in our countries making wood the first renewable energy resource as an alternative to fossil fuels.

An underused energy resource

Only about 60% of the biological growth of the forest is used by the different players of the forestry and wood sector. The remaining 40% represents a tremendous reserves of energy.

An energy that is creating jobs

By definition, the production of wood energy is a proximity production. It greatly helps local jobs.

Manufacturer requirements

  • Chimney installations and Ventilation should conform to requirements of the Building Regulations and any approved local laws and all subsequent standards referred to.
  • A flue draught of 15 Pa is required when running at rated output.
    Additional flue pull shall require a draught stabiliser to be fitted to prevent over-firing.
  • Any pressurised system must have a sufficiently sized expansion vessel and a suitable PRV. In addition the integral anti-boiling quench coil must be connected to a suitable mechanisal safety valve.
  • Accumulator tank with a suitable capacity and recycling kit are compulsory.

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