Tankless Water Heater Installation

A gas tankless water heater installed in Denver starts at $5,600 for a typical home. Gas line upsizing and new venting, when needed, add to that. Send photos and we quote it within one business day, then confirm it in person. The tankless units we install are condensing ENERGY STAR models, which meet Colorado's 2026 low-NOx rule for gas water heaters. Factors that affect cost: • Gas line sizing: Tankless units require higher BTU input than tank water heaters. If your existing gas line is undersized (common in older Denver homes), expect $800 to $2,800 for gas line work. • Venting: Gas tankless units require direct vent or power vent systems. If your existing water heater uses a chimney flue, you'll need new PVC or stainless steel venting ($600 to $1,350). • Electrical: gas tankless units need a 120V outlet for the control board. • Permits: Denver requires permits for gas and electrical work. UniColorado handles all permit applications. Competing Denver contractors quote $6,800 to $8,900+ for gas tankless installation according to plumblineservices.com. Floworksplumbing.com quotes $1,250 to $7,900+, though the lower end of that range is unit-only pricing without installation labor.

**Pros:** • Endless hot water: No recovery time between showers. As long as flow rate stays below unit capacity, hot water is continuous. • 20+ year lifespan: Twice the lifespan of tank water heaters (8-12 years). Rinnai and Navien units routinely exceed 20 years with annual descaling. • More efficient: the U.S. Department of Energy puts tankless at 24-34% more efficient than a tank for homes that use 41 gallons of hot water a day or less, and 8-14% for homes that use around 86 gallons a day. • Space saving: Wall-mounted units free up floor space. A tank water heater occupies 16 square feet of floor space, while a tankless unit occupies less than 1 square foot. • Lower operating costs: Natural gas tankless units cost $100 to $200 less per year to operate compared to gas tank water heaters in Denver. **Cons:** • Higher upfront cost: from $5,600 installed in Denver, compared to from $2,900 for a gas tank. • May require gas line upgrade: Tankless units need 150,000 to 200,000 BTU/hr input, which often exceeds the capacity of existing 1/2" gas lines. Upgrading to 3/4" or 1" gas line adds $800 to $2,800. • 10-15 second hot water delay: Cold water sandwich effect. When you turn on a hot water tap, it takes 10-15 seconds for the burner to ignite and hot water to arrive (longer if the fixture is far from the unit). • Limited simultaneous flow rate: A tankless unit sized for 2 simultaneous showers (5 GPM) will struggle if someone starts the dishwasher or washing machine at the same time. Oversized units or multiple units solve this but increase cost. • Requires annual descaling: Colorado has hard water (7-12 grains per gallon in Denver according to Denver Water). Mineral buildup reduces efficiency and can damage the heat exchanger. Annual descaling costs $150 to $250.

UniColorado installs tankless water heaters from Rinnai, Navien, and Bradford White. These are the three most reliable brands for Denver's climate and water conditions. **Rinnai:** The most popular tankless brand in the U.S., with a 25+ year track record. Rinnai units are known for longevity and parts availability. The RU199iN model is our most common installation for whole-home Denver applications. Rinnai's ControlR smartphone app allows remote temperature adjustment and diagnostics. **Navien:** Excellent condensing efficiency (96% AFUE) and built-in recirculation pumps for instant hot water. The NPE-240A model is the best choice for households that want near-instant hot water at every fixture. Navien units cost $200 to $500 more than comparable Rinnai models but save $30 to $50 per year in gas costs. **Bradford White:** Traditional reliability with lower upfront cost. Bradford White AeroTherm units are a good choice for budget-conscious homeowners who want proven performance without the premium features of Rinnai or Navien. Parts availability is excellent, and local plumbing supply houses stock Bradford White replacement parts. All three brands handle Denver's hard water well with annual descaling. We do not recommend off-brand tankless units (EcoSmart, Titan, Stiebel Eltron) due to parts availability issues and shorter lifespans.