Hydronic Heating, Boilers & Radiant Floors in Littleton, Colorado

Aug 25

7 min read

We're based here. Littleton is the shop's home ground, and most weeks the truck doesn't leave a fifteen-minute radius of it.

That matters more than it sounds. Littleton isn't one kind of house. There's the 1890s and early-1900s brick around Old Town, most of it heated by a system that started life as gravity and got converted at some point by somebody. There are the 1950s and 60s ranches through Columbine and Southglenn. There's Ken Caryl and Roxborough up against the hogback, where the driveways are steep and north-facing and hold ice into April. And there's newer, tighter construction on the Douglas County side that heats on a fraction of what the older stock needs.

A heating system that's right for one of those is wrong for the others. That's the whole job.

What we do in Littleton

Boiler installation and replacement

High-efficiency condensing boilers and standard-efficiency cast iron, chosen against how the rest of the system actually behaves — not against a square-foot chart. Most of the boilers we replace in this town are two to three times larger than the house needs, which is a story of its own further down the page.

Radiant floor heating

New slabs, staple-up with transfer plates into existing joist bays, and Warmboard-style panel systems in remodels. Honest expectations included — radiant floors are not warm floors, they're floors that heat a room, and the distinction disappoints people who weren't told.

Snowmelt and heated driveways

This is Ken Caryl and Roxborough territory. A steep, shaded driveway that gets a freeze-thaw cycle every afternoon is the exact case snowmelt was built for. The catch is timing: the tubing goes in before the concrete, so the decision belongs in the flatwork bid, not after it.

Mechanical room design and system troubleshooting

Boiler plants, zoning, pumps, controls, near-boiler piping. And the call nobody else wants: a system that technically runs but has never worked right, where the answer is upstream of whatever part failed last.

Littleton sits at about 5,350 feet, and your boiler has to be told

Combustion equipment loses capacity as air thins. Manufacturers publish altitude derate tables for exactly this reason, and at Littleton's elevation the correction is not a rounding error — it's the difference between the boiler on the sticker and the boiler you actually own.

Two things go wrong with this locally, and we see both:

The derate never gets applied. Someone sizes off the nameplate, the real output lands short, and on the coldest week of the year the house never quite catches up.

The derate gets applied twice. Someone oversizes to "cover" altitude on top of an already-padded load, and now there's a boiler two and a half times the size of the house — which is worse, not safer. See below.

We pull the manufacturer's altitude data for the specific unit and the specific site, and we write down which number we used. It should be visible in the paperwork, not implied.

Why most Littleton boilers are two to three times too big

This is the most common thing we find, and it's not a small thing.

An older Littleton brick home with some weatherization runs somewhere around 40 BTU per hour per square foot. Newer, tighter construction on the south and Douglas County side of town is closer to 25. Those are the numbers real Front Range houses use.

What gets installed instead is usually sized off the old boiler, and the old boiler was sized off the boiler before it, and somewhere back down that chain someone padded it. Every replacement inherits the padding.

An oversized condensing boiler doesn't just waste money. It short-cycles — fires, satisfies the thermostat almost immediately, shuts off, repeats. And it never gets its return water cold enough to condense, which is the entire reason you paid for a condensing boiler. You bought 95% equipment and you're running it in the mid-80s.

The fix is unglamorous: a room-by-room heat loss on your actual house, with your actual windows and your actual insulation, before anyone picks a model number. It takes longer than reading the old nameplate. It's also the only way the rest of the design means anything.

Old Town Littleton and the gravity conversions

The historic housing stock around Old Town has a particular problem, and it's worth knowing before you get quotes.

Those homes were built with gravity hot water — huge pipes, no pump, water moving because hot water rises. Somewhere in the last sixty years most of them got a circulator bolted on and a smaller boiler dropped in. The distribution system stayed.

That leaves you with enormous thermal mass, very low resistance to flow, and cast iron radiators that were sized for water far hotter than a modern condensing boiler wants to make. Put a mod-con on that system without thinking about it and you get one of two outcomes: the boiler runs hot enough to never condense, or it runs cool enough to condense and the radiators can't put out enough heat on a design day.

There are real answers — outdoor reset curves matched to the emitter, primary/secondary piping, sometimes a buffer tank, sometimes accepting a standard-efficiency cast iron boiler as the honest choice for that house. What there isn't is a default. The system tells you which one, and you have to look.

Snowmelt on the west side

If your driveway runs uphill toward a garage on the Ken Caryl or Roxborough side, you already know what late February does to it.

Two things to understand before you price one:

A driveway asks for several times the heat your house does. A house runs 25–40 BTU/hr per square foot. A driveway holding itself clear during a storm runs around 126 at the reference condition of 5°F air, 10 mph wind and a 38°F surface (Uponor Snow & Ice Melting Manual, Appendix C). On a 1,700 sq ft driveway that's roughly 214,000 BTU/hr — more than most whole houses. Snowmelt is a heat plant with a driveway attached, and the first question is always whether the mechanical room, the gas line and the venting can carry it.

You don't have to heat all of it. Two tire tracks. Just the steep section. Just the apron at the street. The walkway and the steps. Partial coverage is a recognized design, not a compromise, and it's the lever that moves the number most. We price the coverage options side by side.

→ Snowmelt system design and installation

Littleton is three counties, and it matters for permits

Most of Littleton is Arapahoe County, but the city spills into Jefferson County on the west side and Douglas County to the south. Which one you're in changes who inspects the work.

We handle the permit either way. We mention it because it occasionally surprises homeowners who assumed one address meant one jurisdiction, and because a contractor who doesn't know which desk the job goes to is telling you something.

Colorado license LIC00254926.

Where else we work from here

Littleton is home, and we work outward from it: Highlands Ranch, Centennial, Englewood, Greenwood Village, Columbine, Ken Caryl, Morrison, Lakewood, Golden and central Denver. Castle Rock, Parker and Conifer regularly. Statewide for larger snowmelt and boiler-plant work.

→ Serving Denver and the Front Range

What working with us looks like

1. You call or send the details. Square footage, what's there now, what's wrong with it.

2. Site review. We look at the mechanical room, the distribution, the venting and the gas line — not just the box that's failing.

3. Room-by-room heat loss. On your house. Before any equipment gets named.

4. A design and a number, with the assumptions written down so you can check them against anyone else's quote.

5. Install, test, label. Every loop labeled supply and return, so whoever services this in fifteen years can read it.

📞 (303) 908-5658 · Schedule a consultation

Common questions about heating in Littleton

How much does boiler replacement cost in Littleton?

It's driven by what's already there far more than by the boiler itself — the condition of the distribution system, the venting route, the gas line, and whether the water heater is sharing a chimney with the old unit. A straight swap and a job that needs the near-boiler piping rebuilt are different projects. The site review is what turns a range into a number, and we'll tell you which one you're looking at before we write anything down.

My boiler works. Should I replace it?

Not automatically. A cast iron boiler that's been maintained can run a very long time. The questions worth asking are whether it's still safe, whether the venting is sound, and whether it's short-cycling badly enough to be costing real money. We'll tell you if the answer is "leave it."

Can I put radiant floor heating in an existing Littleton house?

Often, yes — staple-up with transfer plates into the joist bays from below, if you have an unfinished basement or crawlspace and the floor assembly cooperates. It's a different animal from a new slab and the output ceiling is lower, so it needs to be designed against the room's actual load rather than assumed to work.

Do you work on the old Old Town houses?

Yes, and they're some of the more interesting work we get. The gravity-conversion systems in that stock need a different approach than a 1990s ranch, which is most of why they get done badly.

Is a high-efficiency boiler always the right call?

No. A condensing boiler only earns its efficiency if the system can return water cold enough to condense. On some older high-temperature radiator systems it can't, and a standard-efficiency cast iron boiler is the honest answer. We'd rather say that than sell the more expensive unit and let you find out in January.

How far into the foothills do you go?

Regularly to Morrison, Evergreen, Conifer and Idaho Springs. Farther for snowmelt and boiler-plant work.