Thanks for the lead-in JJ. Hello Joyce: First, does your "boiler" produce hot water or steam? If it's a steamer, you will have to replace it with a steam-producing boiler. If it's a hot water system with temperatures up to 180 degrees F, I can help you. Please look at the name-plate and find out the Btu's it produces (or consumes), and is it gas? Our Tankless units are very low mass (up to heat very quickly), so we recommend that they be connected to a heating system (load) using a buffer tank, preferably an "Ergomax" tank-type heat exchanger. I can send you information. Please e-mail me with what you have. If I can't help you, I'll help you locate a reputable pro' close to where you live. My number is 1 (800) 851 9891. Thanks Jay, keep up the good work fella's (and Ladies). For safety's sake, please have your gas appliances serviced before winter hits. Best regards to all, Brian in Swampland. Hi Henry.