Designed for bathtubs and small containers up to ~40 gallons
Limited production run, small batch availability
Not everyone needs to heat 200+ gallons of water.
The Micro Woodfire Coil Kit is purpose-built for small-volume bathing; ideal for household bathtubs, whiskey barrels, ice baths, and compact off-grid setups where simplicity and space matter.
This kit uses a fire-powered, pump-free thermosiphon system to circulate and heat water naturally, without electricity or moving parts. It’s optimized for lower water volumes and shorter heat cycles, making it a great fit for real-world low volume bathtub use.
Performance
Rated for small-volume bathing applications (up to ~40 gallons)
Typical heat times: ~1.5–2.5 hours, depending on fire intensity and starting water temperature
(Larger volumes can be heated with proper insulation, but heat times increase significantly. For larger tubs or faster heating, we recommend stepping up to a higher-output kit such as the Backcountry. Remember to always use a lid on your bath while heating for more efficient heat times).
Best for
Standard household bathtubs
Soaker tubs and small outdoor baths
Cut down or small whiskey barrel baths
Small off-grid water heating setups
Not intended for
Most stock tanks and high volume livestock tubs
Large soaking tubs or high-volume systems
Limited drop
This is a limited-run release, produced in a small batch.
Once this run sells through, it may not be restocked.
Note: Due to thermal expansion, smaller coils may relax outward slightly when hot. This is normal and does not affect performance or durability.
Pre-sale details
Ships in approximately 3-4 weeks
Units are already built and awaiting transport
Fire-powered. No pumps. No electricity. No gas.
Just water, steel, and heat.
Built for small baths.
Designed for bathtubs and small containers up to ~40 gallons
Limited production run, small batch availability
Not everyone needs to heat 200+ gallons of water.
The Micro Woodfire Coil Kit is purpose-built for small-volume bathing; ideal for household bathtubs, whiskey barrels, ice baths, and compact off-grid setups where simplicity and space matter.
This kit uses a fire-powered, pump-free thermosiphon system to circulate and heat water naturally, without electricity or moving parts. It’s optimized for lower water volumes and shorter heat cycles, making it a great fit for real-world low volume bathtub use.
Performance
Rated for small-volume bathing applications (up to ~40 gallons)
Typical heat times: ~1.5–2.5 hours, depending on fire intensity and starting water temperature
(Larger volumes can be heated with proper insulation, but heat times increase significantly. For larger tubs or faster heating, we recommend stepping up to a higher-output kit such as the Backcountry. Remember to always use a lid on your bath while heating for more efficient heat times).
Best for
Standard household bathtubs
Soaker tubs and small outdoor baths
Cut down or small whiskey barrel baths
Small off-grid water heating setups
Not intended for
Most stock tanks and high volume livestock tubs
Large soaking tubs or high-volume systems
Limited drop
This is a limited-run release, produced in a small batch.
Once this run sells through, it may not be restocked.
Note: Due to thermal expansion, smaller coils may relax outward slightly when hot. This is normal and does not affect performance or durability.
Pre-sale details
Ships in approximately 3-4 weeks
Units are already built and awaiting transport
Fire-powered. No pumps. No electricity. No gas.
Just water, steel, and heat.
Built for small baths.