A boiler at year fifteen in an old downtown building: repair it, replace it, or retire it
We see a handful of boilers in St. Augustine, nearly all of them in buildings old enough to have radiators. At fifteen years, every one of them reaches the same fork.
The fifteen-year fork for the few boilers in town
A boiler that reaches fifteen years in St. Augustine has usually done it in a building that predates the Bridge of Lions: a Flagler-era inn, a converted house in the Abbott Tract, a commercial building near the Cathedral Basilica with radiators under the windows. The residential subdivisions have none. So the fork at fifteen years is not really about the boiler; it is about the building and what the next owner, the preservation board and the guests will expect from it.
Three paths: repair what is there and plan for another five years, replace the boiler and keep the radiators, or retire the hydronic system in favor of heat pumps that also cool. We quote all three when the building allows it.
Does hydronic heat fit a climate with four frosts?
Barely. Winter lows average between 47 and 51, with four or five frosts in a typical year, and the heating season is measured in weeks. A boiler sits idle from March into December while the real comfort problem, nine months of mid-70s dew points, goes untouched because a boiler does nothing for cooling or humidity.
What hydronic heat does offer, in the right building, is radiant warmth without moving air, which old plaster rooms with high ceilings hold well, and a system that can stay invisible from the street in a National Register district where exterior equipment is restricted.
What a boiler does well here, and what it never will
Well: quiet, draft-free heat on a cold January week; no ductwork in walls that were never meant to be opened; compatibility with the radiators a historic building already has and may be required to keep.
Never: cooling, dehumidification, or air filtration. Any building with a boiler still needs a separate answer for the other nine months, and for the pollen the oaks drop in March.
Against the alternative: a heat pump that also handles August
Set a replacement boiler beside a set of ductless heat pumps for the same building and the comparison is lopsided on paper. The heat pumps heat the few cold weeks for a fraction of the gas, cool from March to November, and dehumidify the whole time. Where the comparison tilts back toward the boiler is preservation: wall heads and outdoor units have to pass review in the historic districts, and some owners would rather keep the radiators and add cooling discreetly than lose the character.
The middle path, keeping the boiler as a backup and letting heat pumps do the mild-day heating, is the one we end up recommending most often.
What moves the price on a boiler job
- Venting. A condensing boiler can vent through a wall in plastic pipe; a conventional one needs a chimney in good order, and old coquina chimneys are not.
- Gas supply. Whether Peoples Gas is already at the building, and whether the existing line is sized for the new unit.
- The loop. The condition of decades-old radiators, valves and piping, and whether the system needs flushing and treatment before a new boiler goes on it.
- Water. Well water in the rural west county needs testing; city water does not.
- Access. Boilers in historic basements and closets rarely come out the way they went in.
We quote the whole job, not just the box, so there is no surprise about the chimney after the boiler is on the truck.
For the handful of radiator houses
Our inn near the Plaza still has cast-iron radiators. Will Cook's work on the boiler behind them?
Yes. We service hydronic systems, and we can replace a boiler that feeds existing radiators or in-floor loops. Which replacement boiler lines Cook’s carries for that work: [[CONFIRM WITH JERRY]]. We will say plainly if the building would be better served by heat pumps.
What happens inside a boiler that sits cold from March until December?
Oxygen in standing water corrodes the inside of the heat exchanger and the fittings, pump seals dry out, and sediment settles. The first firing in December is when the leaks show. A pre-season check in November catches them when they are small.
Does hard Floridan aquifer water shorten a boiler's life?
It can, through scale, in systems that are often topped off with fresh water. City of St. Augustine water is treated and softer than well water, but a closed loop with proper treatment and few make-up events is the real protection. Buildings on wells out toward Elkton need the water tested first.
Could we keep the radiators but add cooling?
Yes, and it is the most common path we recommend: leave the hydronic heat in place for the preservation look and the few cold weeks, and add ductless heat pumps for the nine months of cooling. The heat pumps also cover mild heating days so the boiler fires less.
Have one of the few boilers in St. Johns County?
Call. We'll tell you honestly whether it is worth another decade.