September 21, , Wow, time goes by fast. I’ve an indoor boiler with a 9 gallon water jacket and have it plumbed to pump the hot water through three baseboard heating zones with each pump controlled by its own zone thermostat. For the first 10 years, this wood boiler took the place of an oil boiler, unless I was gone and couldn’t keep the wood fire going. The last 25 years the oil boiler was replaced with a gas boiler for backup. Usually only put the system in this mode if needing very little night-time heat and just build one small fire in the evening. Last winter, the gas boiler ran only one weekend out of the entire winter.