If you’re heating your home with traditional fuels and looking to reduce costs or increase energy independence, integrating an Indoor Wood boiler like the Wood Gun™ into your existing system can be a game-changer. A properly installed wood gasification boiler can burn efficiently, reduce emissions, and deliver consistent heat—even when tied into older systems.
In this guide, we’ll walk you through the key considerations and best practices for connecting a wood boiler to your current hydronic (hot water) heating setup.
Why Integrate a Wood Boiler?
An Indoor wood boiler uses renewable wood fuel to produce heat for your home’s heating system and domestic hot water. When integrated correctly with an existing system, it can:
- Reduce heating bills
- Lower reliance on fossil fuels
- Provide backup or supplementary heat
- Stay warmer for less.
The Wood Gun™ Super E110, for example, is a gasification wood boiler designed for maximum efficiency and clean combustion. It’s ideal for homeowners who want serious performance without sacrificing sustainability.
Planning Your Wood Boiler Integration
1. Choose a Parallel or Series Configuration
The most common method is parallel piping, which allows your wood boiler to operate alongside an existing oil or gas boiler. This way, either system can heat your home independently, depending on the conditions.
🔁 Parallel Piping Configuration
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Flow Path: Water flows through either the wood boiler or the backup boiler independently.
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Operation: Allows for independent or simultaneous operation of both boilers.
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Efficiency: Reduces unnecessary heat loss; each boiler operates only when needed.
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Maintenance: Easier to isolate and service individual boilers without affecting the entire system.
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Flexibility: Ideal for systems requiring backup heating or staged operation.
🔗 Series Piping Configuration
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Flow Path: Water flows sequentially through the wood boiler and then the backup boiler.
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Operation: Both boilers are active in the heating loop; the backup boiler receives pre-heated water from the wood boiler.
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Efficiency: Can lead to heat loss if one boiler is idle; less efficient during partial load conditions.
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Maintenance: Servicing one boiler may require shutting down the entire system.
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Simplicity: Simpler piping layout; suitable for systems where both boilers operate together consistently.
Choosing the Right Configuration:
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Parallel: Best for systems needing flexibility, independent operation, and easier maintenance.
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Series: Suitable for simpler systems where both boilers operate together, and installation simplicity is a priority.
The Wood Gun manual recommends parallel installations for maximum flexibility and reliability.
2. Ensure Proper Pressurization and Circulation
Your indoor wood boiler must be pressurized correctly (typically 12–18 psi) to operate safely and efficiently. This helps prevent corrosion and eliminates oxygen infiltration into the system.
It’s also important to size your circulator pumps properly. Because wood boilers operate best with a 20-degree temperature drop in the water leaving the boiler compared to the water returning, every 10 gpm is equal to 100,000 BTU/hr. You will need to know your home’s heat load. The easiest way is to look at the rating of your existing heating system. If it is 200,000 BTU/hr, then you will need a pump capable of pumping 20 gpm through the boiler.
The Wood Gun SE110 can control its circulator/zone pump via an onboard relay. Always connect the pump to run only when the water temperature is above a set threshold.
3. Add an Expansion Tank and Mixing Valve
To protect your system from pressure fluctuations and condensation issues:
- Install an expansion tank to handle pressure changes.
- Use a mixing valve to keep return water temperatures above 160°F. This reduces the risk of condensation. Condensation can lead to corrosion and/or reduced efficiency.
4. Consider the Space Requirements
Before tying in an indoor wood boiler, make sure your chosen installation area meets space and safety code requirements.
🔥 Clearances to Combustibles (Minimum):
- Front: 24 inches (48 inches recommended for access)
- Rear: 6 inches (30 inches recommended)
- Left: 6 inches (50 inches with backup system)
- Right: 6 inches (24 inches recommended)
- Top: 6 inches
- Stovepipe: 18 inches
- Floor: Non-combustible surface only (e.g., concrete, tile, brick)
📏 Minimum Room Size for Wood Gun™ SE110:
- 11 feet (front to back)
- 6 feet wide (10 feet if a backup system is included)
- 6 feet ceiling height minimum
Also, leave extra space for loading wood, ash removal, and maintenance. Adequate clearance ensures fire safety and improves long-term usability.
5. Consider Thermal Storage
Adding a thermal storage tank can significantly improve system efficiency and reduce cycling. It allows excess heat from your wood boiler to be stored and used later when demand rises. This also minimizes the need for constant firing, especially in shoulder seasons.
Pro Tips for a Smooth Wood Boiler Installation
- 🔥 Use seasoned wood (19–28% moisture) to ensure efficient combustion and reduce creosote buildup.
- 🧯 Seal all flue pipe joints with high-temp silicone—positive flue pressure requires airtight seals.
- 🛑 Never connect your wood boiler to a chimney serving another appliance.
- 🛠️ Install a CO detector and smoke detector in the boiler room.
- 📜 Follow all local building codes and hire a qualified installer when needed.
Final Thoughts
An indoor wood boiler like the Wood Gun™ SE110 offers homeowners a powerful, efficient way to take control of heating costs while using renewable fuel. Tying it into your existing system isn’t just feasible—it can transform how you heat your home for years to come.
Just make sure to follow proper installation practices and always prioritize safety and efficiency.
Need help integrating a wood boiler into your system?
Reach out to a certified installer or contact Alternate Heating Systems for expert support and guidance.