In the Colorado Springs market, replacing a standard-efficiency gas boiler typically runs $6,000 to $10,000 installed. A high-efficiency condensing boiler typically runs $9,000 to $16,000, and a combi boiler that handles both heat and domestic hot water typically runs $8,000 to $14,000.
Those are typical market ranges for our area, not a quote. Before you use them, though, there is a question worth settling first, because boilers are the one piece of home mechanical equipment most often replaced when it did not need to be.
A boiler is a fairly simple appliance surrounded by a lot of small parts, and it is almost always one of the small parts. The usual suspects:
Cast iron boilers commonly run thirty to fifty years. A well-maintained one heating a house evenly at thirty-five years old is not a replacement candidate simply because a salesperson pointed at its efficiency rating. Run that math honestly: moving from an older 80 percent unit to a 95 percent unit cuts roughly fifteen percent off the heating portion of your gas bill, and against a five-figure installed cost, the payback period is long. Efficiency alone rarely justifies replacing equipment that works.
Replace it when the reasons are structural: a cracked block or section, a leaking heat exchanger, repeated failures across different systems, parts that are no longer manufactured, an unsafe combustion or venting condition that cannot be corrected, or a genuine capacity mismatch with the house.
Typical market ranges for our area:
| Job | Typical Colorado Springs market range |
|---|---|
| Circulator pump replacement (repair) | $400–$900 |
| Expansion tank replacement (repair) | $300–$700 |
| Zone valve or zone control repair | $400–$1,200 |
| Standard-efficiency gas boiler, installed | $6,000–$10,000 |
| Combi boiler (heat plus domestic hot water), installed | $8,000–$14,000 |
| High-efficiency condensing boiler, installed | $9,000–$16,000 |
| Add: near-boiler piping rebuilt during replacement | $1,000–$3,000 |
| Add: new venting and condensate drain for a condensing unit | $800–$2,500 |
| Add: new or rebuilt zoning and controls | $500–$2,500 |
| Converting a hydronic system to forced air | $10,000–$25,000+ |
The three "add" rows are the ones that separate a real quote from a phone estimate. A boiler price without them is a number for a box sitting on a pallet.
Near-boiler piping is the arrangement of pipe, pumps, valves, and air separation immediately around the unit, and it is where boiler installations succeed or fail. A condensing boiler in particular has specific requirements about flow rate and return water temperature, and reusing forty-year-old piping designed for a completely different appliance is the most common reason a new high-efficiency boiler underperforms or fails early. When a quote is noticeably cheaper than the others, this is usually the difference.
A standard-efficiency boiler typically vents through an existing chimney or flue. A condensing boiler does not: it produces cool, acidic exhaust that has to go out through sealed plastic venting, usually through a sidewall, and it produces condensate that needs a drain and often a neutralizer. That is new work in a house that never had it.
Worth knowing before you shop. If your boiler and your gas water heater currently share a chimney, and the boiler moves to sidewall venting, the water heater is left alone on a flue that is now badly oversized for it. That causes poor draft and condensation inside the chimney. The fix is a liner or a change in the water heater's venting, and it is a real line item that should appear in the quote rather than in a surprise phone call halfway through.
Output sizing, cast iron versus stainless or aluminum heat exchangers, zoning and controls, whether the system feeds radiators or baseboard or in-floor tubing, gas line capacity for the new input, and access. A basement mechanical room at the bottom of a narrow 1920s staircase is a labor line whether anyone writes it down or not. In older homes, suspected asbestos insulation on the old piping is a specialist abatement cost and is not part of a boiler quote.
We diagnose first. If it is a circulator, a zone valve, or a control, we say so and fix it, rather than starting the conversation at a replacement.
Book a Heating Visit →Gas-fired equipment loses input capacity as elevation increases, which is why manufacturers publish high-altitude derate tables and conversion kits. At 6,035 feet, a boiler cannot be selected off its sea-level nameplate and left at factory settings. It has to be sized and set up for our elevation.
What that means for you as a homeowner is simple enough. A boiler that was sized as though it were installed at sea level will be short on the coldest nights, which shows up as a house that never quite catches up in a cold snap rather than as an obvious failure. A boiler that was oversized to compensate for a derate that was already accounted for will short-cycle, which wastes fuel and wears the unit. Both are setup errors, not equipment defects, and both are avoidable by asking one question: has the heat loss calculation and the altitude derate been done for this house specifically?
Combustion setup matters here for the same reason. Air is thinner, and the fuel-air mixture has to be adjusted and verified with an analyzer rather than assumed. On atmospheric equipment venting into an old masonry chimney, draft is worth verifying too, particularly on the coldest days when a cold chimney is slowest to establish it.
Hydronic heat is common in the older parts of town because it was the standard when those houses were built. The Old North End, Patty Jewett, the Westside, downtown, and much of Manitou Springs are full of homes with cast iron radiators, and a fair number of those systems began life as gravity systems and were converted.
They are worth keeping. Radiant heat off cast iron is even, quiet, and does not blow dust around a house, and the mass of the system means the temperature does not swing the way forced air does. In a climate with our daily temperature range, that is a genuine comfort advantage rather than nostalgia.
The usual reason people consider tearing it out is air conditioning, since a hydronic house has no ductwork to cool through. Converting the whole house to forced air to solve that is a large remodel with a five-figure price attached, and it means losing the heat you already like. Ductless mini-splits are the alternative worth pricing first: they add cooling room by room without touching the boiler. Our high altitude HVAC guide covers how heating and cooling equipment behaves differently up here in more detail.
For heating work generally, see our heating and cooling page. Boiler systems sit across the plumbing and heating trades, and we handle both sides of that in house, which matters when the fix involves the piping rather than the appliance.
We diagnose the actual failure before anyone quotes a replacement, and we say so when the answer is a $500 part. 579 Google reviews at 4.9 stars.
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