You have an existing oil boiler and want to switch to pellet. You have two paths: a pellet burner that replaces the existing oil burner, or a complete pellet boiler that replaces the entire existing boiler. The two options are not equivalent, in cost or in performance.
The pellet burner: what it is
A pellet burner is a standalone combustion unit that replaces the oil burner. The boiler stays the same, only the combustion mechanism changes. The burner draws pellets from a nearby silo through an auger, burns them, and heat is transferred to the boiler’s water via the existing combustion chamber.
Installation requirements
- Existing boiler in good condition (refractory lining, flue channels, water pipes)
- Space for a pellet silo near the boiler (or a remote silo with a longer feed auger)
- Electrical supply for the burner and auger
- Chimney adjustment if needed (pellet flue gas is cooler)
The complete pellet boiler: what it is
A full unit designed for pellet from the ground up. Combustion chamber, flue chamber, heat exchanger, burner, pellet tank, all integrated or adjacent. AXINAR’s PelIT and PelletWork series range from 20kW to 150kW.
Characteristics
- Combustion chamber optimized for the lower pellet flame temperature
- Multiple flue-gas paths for higher efficiency
- Automatic cleaning
- Integrated control system with temperature sensors
Comparison
| Pellet Burner | Pellet Boiler | |
|---|---|---|
| Required infrastructure | Existing boiler | New installation |
| Installation time | 1 to 2 days | 2 to 4 days |
| Combustion efficiency | Good (85 to 92%) | High (90 to 95%) |
| Optimal output temperature | Limited by the existing boiler | Optimized for pellet |
| Power range | 20 to 150 kW | 20 to 150 kW |
| Service life | 10 to 15 years for the burner, depends on the boiler | 15 to 25 years for the whole system |
When to choose a pellet burner
- The existing boiler is up to 10 to 15 years old and in good shape
- You want to minimize initial investment
- Boiler room space doesn’t allow full boiler replacement (e.g. tight access, size)
- You have a medium-size home (100 to 200 sqm)
- You want a quick oil-to-pellet switch this season
When to choose a complete pellet boiler
- The existing boiler is old (20+ years), corroded, or has low efficiency
- You’re expanding heating (added floor, larger area)
- You want a long-term solution with maximum efficiency
- You have a commercial space (>150 sqm) where a 5 to 8% efficiency gap translates to real savings
- You want full control (lambda sensor, auto cleaning, electronic management)
Retrofit pitfalls with a burner
The boiler must be suitable
Older cast-iron oil boilers had refractory material in the combustion chamber. Modern condensing oil boilers are not suitable for pellet, because the combustion chamber is designed for a liquid fuel and creates “thirsty” spots in a pellet flame.
The chimney needs a check
Pellet produces flue gas at lower temperatures than oil (~150°C vs 200 to 250°C). If the chimney is oversized or uninsulated, condensation forms, and over time creates buildup inside the flue.
The auger must be sized correctly
For a silo-to-burner distance > 2m an intermediate auger is needed. Wrong length or angle equals blockage or intermittent feed, and the flame goes out.
AXINAR offers both solutions: Apoplim (AP20/30/45) and Tsovea (TS75/95/120/150) analog pellet burners, plus complete PelIT and PelletWork burner-boiler systems.
- Pellet burners 20 to 150 kW with auto cleaning
- Pellet boilers with multiple flue-gas paths
- Conical pellet silos 310L and 1500L
- Full technical support for selection and installation
Request a quote for your home
Tell us: the area you need to heat, the type of existing boiler (if any), and the boiler room space. We reply with a burner or boiler proposal based on what actually makes sense.
See also: Boiler power per square meter guide, Pellet burner for 120 sqm: retrofit an existing boiler.
