When sourcing wholesale pellet stove water heaters, prioritize the Total Heat Output (kW) and the Water Heat Output ratio. Ensure the unit has a high-efficiency rating (at least 85%+) to reduce fuel consumption. Key components should include a high-grade stainless steel or cast iron heat exchanger, an integrated expansion tank, and a high-pressure circulation pump. Additionally, verify the hopper capacity to ensure it meets the end-user's autonomy requirements (typically 24-48 hours of continuous operation).