I had Firelight come out for an unusual reason: to determine if the masonry monstrosity in the center of my home was an original thermal mass heating system, and IF SO, to check the chimney to determine if it is safe to use the firebox in the basement. I found the company to be very professional, all the way from first contact, several calls to schedule, and through to to arrival. The tech was on time and followed instructions to call 5-minutes out so I could corral my protective German Shepherd. The tech was impressively knowledgeable about ancient heating systems, and did a thorough inspection of the masonry and mortar on all three floors and gave me wise advice, which I very much appreciated. I was surprised the tech knew about thermal mass heating that was common in the 1800's to about the mid 1920's. I think he enjoyed getting an unusual service call. Nothing was broken, I just needed confirmation of my suspicion, a chimney/mortar inspection, and advice on safety. I had them do a full inspection on this...monstrosity. Note there is NO FIREPLACE--there has never been one, but there IS a firebox and clean out in the BASEMENT! SEE PHOTOS and descriptions for details. Turns out--this thing IS an original heating system from 1920. Thermal Mass. It was used by building a small hot fire in the basement firebox, load some coal, and let it go. The heat is captured in the brick and held like a battery, released over time. The main floor section is a SOLID MASS OF BRICK. There was never a fireplace there. When the fire burns down, the warm bricks give off heat on the main floor for 8-10 more hours. Thermal Mass Heating. --Rightly, I was advised it's not a good idea to use it, but in case of an emergency... I could. It will still work as intended and the chimney is safe for occasional emergency use. --Later, in the 1940's, someone tied into the flue on the main floor for a wood stove, then in the 1960's that was closed off when natural gas was installed, along with cast iron baseboards--heated by a gas boiler. Hydronic heat via cast iron baseboards is the Best Heat Ever. No blowing air. Just Warm, Penetrating Deep Warmth. Hydronic Radiant Heat heats OBJECTS, not air. THANK YOU FUSE!!! read more