The Hardy heater firebox is constructed of 14 and 16 gauge 304 stainless steel for the best heat transfer possible. The heat transfer efficiency is three times better with 16 gauge 304 stainless steel than with 3/8" carbon steel. The all stainless steel firebox also resist rusting and burnout that occurs on standard carbon steel. The insulated all stainless steel firebox door and ash door holds the heat and resist burnout and corrosion. The firebox comes standard with thick heavy cast iron grates to make weekly ash removal simple and fast.
The use of chemicals inside the water tank is not necessary because of the corrosion resistance of 304 stainless steel. Since hot water evaporates, Hardy invented a condenser stack located on the rear of the heater that condenses the steam and returns it to the water tank. The water tank is vented to the atmosphere to eliminate the safety hazards common with a pressurized boiler.
Standard features on Hardy heaters are an adjustable aquastat, combustion blower for damper control, 4 GPM at 20 feet of head stainless steel circulator pump with on/off control relay, and automatic water level controls. The Hardy provides hot water for hot air duct systems, water baseboard, radiant floor heat, unit heaters and other existing hydronic systems.
The outside cover is constructed of 24 gauge 304 stainless steel to give you years of maintenance-free service. The stainless steel cover will not fade, needs no painting and does not require any weather protection. The primary Hardy design goal is to give years of good service and make it easy to maintain.