Heating InstallationMilford, MAResidential

Steam Boiler Replacement

Project Overview

Emergency boiler failures are among the most urgent calls we receive, especially during Massachusetts winters. When a family calls at night with no heat and temperatures in the single digits, every hour matters. This Milford duplex replacement tested our ability to respond fast without cutting corners.

Steam boiler replacements are more complex than standard forced-air furnace swaps. The near-boiler piping must be precisely configured for proper steam distribution, and the system must be carefully pressure-tested to ensure no leaks. Our team's experience with older New England homes — many of which still run on steam — allowed us to execute this replacement quickly and correctly.

The new Weil-McLain ECO 155 is among the most efficient steam boilers on the market, with an AFUE rating of 87.2%. The outdoor reset control adjusts boiler firing based on outside temperature, so the system uses only as much energy as needed. The homeowner reported noticeably lower gas bills starting the very first month.

The Challenge

A 30-year-old steam boiler catastrophically failed on a 10°F night in a two-family Milford duplex. The boiler's heat exchanger had cracked, causing water to leak onto the basement floor. Both units in the duplex — one occupied by an elderly couple in their 80s and the other by a young family with an infant — were left without heat in dangerous cold. The homeowner called three HVAC companies before reaching Mass HVAC; all others quoted 5–7 day wait times due to the winter emergency backlog. Indoor temperatures had already dropped to 48°F and were falling.

Our Solution

Our emergency response team arrived within 2 hours of the call. We immediately set up two portable propane heaters to stabilize indoor temperatures and prevent pipe freezing — critical in a duplex with separate plumbing runs. The next morning, our crew removed the failed boiler and began installing a new Weil-McLain ECO 155 high-efficiency steam boiler. Despite the complexity of a steam system (which requires precise piping pitch, proper near-boiler piping, and careful pressure testing), we completed the full installation in 48 hours. We replaced the aging pressure relief valve, installed a new low-water cutoff for safety, and added a digital boiler control with outdoor reset capability. Both units had full heat restored before the next cold snap.