Burnham: boiler retrofit: modern condensing heat in a system built for another era

Swapping an atmospheric boiler for a condensing model is rarely plug-and-play. Condensing boilers need sealed venting and a condensate drain, they need cool return water to actually condense, and they modulate against outdoor and system conditions. A retrofit scopes and executes those adaptations so the new boiler operates the way its design assumes.

Retrofit projects range from a wall-hung condensing boiler with dedicated venting dropped into a clean basement space, to rewiring zone controls, adding return-temperature protection for high-temperature emitters, rerouting flues and rethinking combustion air in a tight mechanical room. Each is assessed on site and performed under the gas and heating permits the work requires.