Commercial Boilers & Steam

By testing it, not by looking at it. A trap failed closed gives you a terminal unit that stays cool while everything around it heats, because condensate has nowhere to go. A trap failed open gives you the opposite signature: an unusually hot return line, banging, a receiver venting steam, and neighbouring spaces that overheat while a far one starves. We check temperature across the trap and listen to it under load, then tag each one so the repair list is a document rather than an opinion.

Because condensate is leaving and not coming back. Usual sources: buried or concealed return piping that has corroded through, traps blowing steam into the return until it flashes off at the vent, a receiver or feed unit overflowing to drain, or a relief valve seeping. It matters more than it sounds. Every gallon of makeup brings dissolved oxygen into a steel vessel, and oxygen pitting is what ends most commercial boilers well before the burner does. Logging the meter for a week is the first thing we ask a building to do.

Capacity and boiler type; whether the new plant is a single vessel or modular units that can fit through the door in pieces; the state of the near-boiler piping and header, which we rebuild rather than reuse; venting, because a condensing plant will not go up the old masonry chimney; gas service and electrical capacity; rigging the old sections out of a room that was built around them; and permits and inspection. Demolition and rigging are frequently the biggest surprise on a job like this, which is why we scope them on the survey rather than later.

Sometimes, and it is a bigger project than it sounds. Converting means the distribution and every terminal unit changes, not just the boiler — one-pipe radiation cannot carry water, and the piping was never sized for it. It is worth studying when the building is being gutted anyway, when the radiation is being replaced, or when the goal is a condensing plant that needs low return temperatures to do any good. In an occupied building with sound steam piping, fixing the venting and the traps usually buys more comfort for far less disruption than a conversion would.

Wet steam is water being carried out of the boiler with the steam, and it comes from the near-boiler piping being wrong, the water line being too high, the water being dirty or oily after a repair, or the boiler being fired harder than its steam chest can keep up with. Banging is that water meeting steam somewhere it should not — a main that has lost its pitch, a missing or blocked drip leg, or condensate sitting in a run. Both are fixable, and both are piping work rather than boiler work.

Annually at minimum, before the heating season, with combustion set by analyser and every safety device tested. Steam plants also want a mid-season check on water level, blowdown and the feed unit. Boilers running through the summer for domestic hot water are on their own schedule. Buildings with a jurisdictional boiler inspection also need the plant presented in a state that will pass, and we schedule around that.

The straightforward answer is to do the work in summer, and that is what we push for on every occupied residential building. Where a replacement has to happen in the cold, the options are temporary boilers connected at the header, phasing a modular plant so one boiler carries the building while the next is set, or keeping the existing vessel in service until the new one is piped and proven. All three cost more than doing it in July.

Yes — oil burners, gas conversions and dual-fuel burners with the changeover controls and the tank-side equipment that comes with them. Converting an older oil plant to gas is common in this footprint and worth costing properly, because the burner is the cheap part and the venting, gas service and controls are not.