Done works on virtually every type of residential heating and cooling system found in the Denver and Front Range area — from gas furnaces and central air conditioners to boilers, heat pumps, and ductless mini-splits. If it keeps your home comfortable, our licensed technicians are trained and equipped to repair, maintain, or replace it. We’ve been serving Colorado homeowners since 1999, so we’re well acquainted with the equipment choices and challenges specific to our high-altitude, high-swing-temperature climate.

Gas Furnaces and Central Air Conditioners

The most common setup in Denver metro homes is a gas forced-air furnace paired with a central air conditioner that shares the same ductwork. Done works on all major brands — Carrier, Trane, Lennox, Rheem, Goodman, and others — regardless of age or efficiency rating. Our technicians handle everything from igniter replacements and heat exchanger inspections to blower motor repairs and refrigerant recharges.

Colorado’s altitude (around 5,280 feet in Denver, higher in the foothills and mountains) affects how gas appliances burn. Furnaces and boilers are derated at elevation — typically 4% per 1,000 feet above sea level — which is why proper sizing and combustion tuning matter more here than in lower-altitude markets. Our technicians account for altitude when diagnosing performance issues and when recommending replacement equipment.

Boilers and Hydronic Heating Systems

Older Denver neighborhoods — particularly those with homes built before the 1970s — often have boiler-based hydronic heating systems rather than forced-air furnaces. Done services both hot-water boilers and steam boilers, including repair, annual maintenance, zone valve issues, expansion tank replacements, and full system replacements when a boiler has reached the end of its service life.

Colorado’s hard water (elevated calcium and magnesium levels common throughout the Front Range) accelerates mineral scale buildup inside boiler heat exchangers and piping. This scale reduces efficiency and can eventually cause overheating and premature failure. Our technicians inspect for scale as part of any boiler service call and can advise on water treatment options to extend system life.

Heat Pumps

Heat pumps have become an increasingly popular choice for Colorado homeowners looking to reduce gas consumption and take advantage of utility rebate programs. A heat pump moves heat rather than generating it — in summer it works like a central AC, and in winter it extracts heat from outdoor air to warm your home. Modern cold-climate heat pumps are designed to operate efficiently down to temperatures well below freezing, which matters given the Front Range’s periodic cold snaps.

Done installs, repairs, and maintains both standard heat pumps and cold-climate models. We can also help you evaluate whether a heat pump makes sense for your home given your existing ductwork, your energy costs, and your heating load — a calculation that looks different at 5,500 feet in Evergreen than it does at 5,200 feet in Aurora. Visit our heat pump service page to learn more about what we offer.

Ductless Mini-Split Systems

Ductless mini-splits are an excellent solution for homes without existing ductwork, additions that are difficult to tie into the central system, or homeowners who want zoned comfort control. Each indoor air handler serves a specific room or zone independently, so you’re not heating or cooling spaces that aren’t in use. Done installs single-zone and multi-zone mini-split systems from leading brands and handles all ongoing maintenance and repairs.

Mini-splits also work well in Colorado’s dramatic day-to-night temperature swings. In Denver, a summer day might hit 95°F while the overnight low drops into the 60s — mini-splits respond quickly to those changes without the energy waste of conditioning an entire house. See our ductless mini-split page for system options and installation details.

What We Cover Across All System Types

Regardless of the system type, Done offers a consistent range of services: diagnostic and repair calls, seasonal maintenance tune-ups, full system replacements, and emergency service when your heat goes out on a January night or your AC quits during a July heat wave. Here’s a quick summary of the system categories we service:

  • Gas furnaces — all brands, single-stage through modulating, including high-efficiency condensing models
  • Central air conditioners — standard SEER and high-SEER systems, all refrigerant types including R-410A and newer R-454B
  • Boilers — hot-water and steam, residential and light commercial, gas and propane-fired
  • Heat pumps — standard and cold-climate models, dual-fuel hybrid systems
  • Ductless mini-splits — single-zone and multi-zone, heating and cooling
  • Thermostats and controls — programmable, smart, and zoning control systems across all equipment types

If you’re not sure what type of system you have — or if you’re comparing options for a replacement — our team is happy to walk you through it. Explore our full cooling services and heating services, or check out our Care Club maintenance membership to keep whatever system you have running at peak efficiency year-round. Ready to schedule? Contact Done and we’ll get you taken care of.