The GARN WHS (Wood Heating System) Product Line:







Download Brochure

Download Cut Sheet

Download Cut Sheet

Download Cut Sheet

Dimension Sheet

Dimension Sheet

Dimension Sheet

Dimension Sheet

Maximum Heat Output †180,000 btuh250,000 btuh325,000 btuh700,000 btuh
BTU’s of storage (120 F to 195 F)630,000 btus920,000 btus1,170,000 btus2,050,000 btus
Tested Efficiency (LHV)80.0% *80.0% *88.4% *85.0%
Particulate Emissions output – PM2.50.190 lbms/mmbtu0.131 lbs/mmbtu0.088 lbs/mmbtuNot Tested
Particulate Emissions rate – PM2.52.31 gr/hr2.87 gr/hr1.65 gr/hrNot Tested
Nominal gallons of storage980 gallons1,420 gallons1,830 gallons3,200 gallons
Weight – Empty2,200 lbs.3,140 lbs.3,570 lbs.7,500 lbs.
Weight – Filled10,370 lbs.15,000 lbs.18,830 lbs.34,500 lbs
Recommended wood length16″ to 24″24″ to 32″24″ to 32″24″ to 42″
Recommended wood diameter3″ to 10″3″ to 10″3″ to 10″4″ to 12″
Combustion chamber length36″40″40″50″
Combustion chamber diameter23″25″25″40″
Combustion chamber volume110 gallons130 gallons130 gallons250 gallons
NPT supply flange1-1/2″ (18 gpm MAX)2″ (25 gpm MAX)2″ (33 gpm MAX)3″ (70 gpm MAX)
MPT return pipe1″1-1/2″1-1/2″2-1/2″
Draft inducer motor1/2 HP1/2 HP3/4 HP3/4 HP
Electrical requirements115 VAC 15 amp115 VAC 15 amp115 VAC 15 amp115 VAC 15 amp
Flue diam. (2100°F Class A)6″6″6″10″
Air intake diam. (single wall)
– Includes screened intake hood


†Maximum heat output is based on reloading once every 3 hours with 24 inch long split white oak, with 20% moisture content. Output rate is fuel dependent and will vary with wood type, moisture content, size and reloading frequency. GARN® WHS units are certified safe to burn cord or slab wood, densified wood briquettes and air dried corn on the cob.

*Tested to ASTM-E2618

GARN WHS Manuals:

The GARN WHS/ETS Off-Peak Electric Heating Product Line:

Did you know that you can turn your GARN WHS into a complete electric heating system for less money than buying an electric boiler?  The GARN Unit’s thermal storage makes it an ideal piece of heating equipment to use your utility’s Off-Peak Electric Heating programs.  Take advantage of low-cost, discounted electric rates that cost less than heating with fuel oil or propane.

Controller and Sequencer Small


Read about the benefits of heating with Off Peak Electricity:

GARN® Electric Heating Package Literature

Learn how to install the GARN Electric Heating Package by downloading the manual:

GARN® Electric Heating Package Owners Manual

Subscribe To GARNews

Join our monthly mailing list to receive the latest news and updates from our team.

You have Successfully Subscribed!