Indoor Pellet Boilers

An indoor wood pellet boiler is an automatic central heating boiler that burns compressed wood pellets to heat water for hydronic systems. An auger feeds pellets from a hopper into the burn chamber on demand, and the boiler transfers that heat into water for radiant floors, fan coils, domestic hot water support, workshops, farms, and building heat.

The indoor part matters because the boiler is planned as mechanical-room equipment with venting, piping, pumps, controls, protection valves, and thermal storage. It is selected as a complete hydronic system, not as a room heater, and its automatic fuel feed makes it closer to a gas or oil boiler in day-to-day use than to a hand-fired appliance.

MBTEK indoor pellet boiler systems are built around hydronic heat distribution and automatic pellet feed. ATLAS is the compact, appliance-style boiler for homes and light commercial spaces, Phoenix adds a large built-in hopper with self-cleaning support and app-ready control, Pellet Duo delivers higher output with multi-fuel flexibility, and Pellet Duo Industrial scales up to commercial and industrial heating loads.

A complete system can include a buffer tank, boiler protection valve, circulator pumps, controls, radiant floor loops, fan coils, air handlers, and an indirect tank for domestic hot water. The product picker and sizing tables above keep those boiler links close to the top so buyers can move from research to model selection quickly.

A pellet boiler runs on renewable wood pellets instead of natural gas, oil, or propane, which can lower fuel cost and carbon footprint where pellets are readily available. MBTEK pellet boilers operate at up to 96% efficiency depending on the model, with automatic fuel and airflow modulation that keeps day-to-day use close to a conventional fossil-fuel boiler.

The tradeoffs are pellet storage and fuel handling: pellets need dry storage and periodic restocking, and ash must be managed. In return you get a high-efficiency, automatic boiler that can replace or supplement an oil or propane system on the same hydronic loop.

A correctly sized pellet boiler can heat an entire house and support domestic hot water. The boiler ties into the hydronic system, and an indirect tank uses boiler heat to produce domestic hot water alongside space heating.

A buffer tank is often part of a whole-house plan because it stores heat, smooths out demand, and reduces boiler cycling. Large hoppers on Phoenix and Pellet Duo models give several days of autonomy between refills, which keeps a whole-house system practical to run.