# Duality Heating and Air

> Comfort, in perfect balance. Denver-based, locally owned HVAC company run by one licensed technician. Open 24 hours. From Golden to Aurora, Castle Rock to Thornton.

- Phone: (720) 447-0177 (call or text, 24/7)
- Email: info@duality-comfort.com
- Address: 3940 S Hazel Ct, Englewood, CO 80110
- Rating: 5.0/5 on Google (12 reviews)
- Prices: $99 seasonal tune-up · $99 emergency diagnostic (credited toward repair) · $99 indoor air quality assessment · everything else quoted in writing first
- Credentials: Colorado LLC, Licensed, Bonded, Insured, NATE-Certified, EPA 608 Certified
- Payment: Cash, Check, Visa, Mastercard, American Express, Discover, Apple Pay, Google Pay, Zelle, Venmo, Financing
- Book: https://dualitycomfort.com/book/ (about 30 seconds; a dispatcher calls back within minutes)
- Not offered: boiler or radiant-heat service
- Last updated: 2026-10-13

## Services
- [Heating](https://dualitycomfort.com/services/heating/): Furnace repair, replacement, and $99 tune-ups. Same-day, any brand, sized for Denver altitude.
- [Cooling](https://dualitycomfort.com/services/cooling/): AC repair and new systems, heat pumps, and mini splits. Fast dispatch when it quits on a hot day.
- [Indoor Air Quality](https://dualitycomfort.com/services/indoor-air-quality/): Humidifiers, filtration, purifiers, and duct sealing. Breathe easier through dry winters and smoke season.
- [Green Energy](https://dualitycomfort.com/services/green-energy/): Low-NOx furnaces, cold-climate heat pumps, ENERGY STAR equipment. We file your Xcel rebates.
- [Comfort Plans](https://dualitycomfort.com/services/maintenance-plans/): Two tune-ups a year, priority scheduling, and no surprise breakdowns. The cheapest HVAC decision you’ll make.
- [24/7 Emergency Repair](https://dualitycomfort.com/emergency/): same-day, no overtime fees, $99 diagnostic
- [Pricing](https://dualitycomfort.com/pricing/): the three $99 offers and how every other price is written before work

## Common problems (causes, safe checks, what the fix involves)
- [Furnace Blowing Cold Air](https://dualitycomfort.com/problems/furnace-blowing-cold-air/)
- [AC Not Cooling](https://dualitycomfort.com/problems/ac-not-cooling/)
- [Furnace Short Cycling](https://dualitycomfort.com/problems/furnace-short-cycling/)
- [AC Frozen](https://dualitycomfort.com/problems/ac-frozen/)
- [Furnace Making Noise](https://dualitycomfort.com/problems/furnace-making-noise/)
- [Water Leaking From Furnace or AC](https://dualitycomfort.com/problems/water-leaking-from-furnace/)
- [Thermostat Not Working](https://dualitycomfort.com/problems/thermostat-not-working/)
- [High Gas Bill](https://dualitycomfort.com/problems/high-gas-bill/)
- [Uneven Temperatures](https://dualitycomfort.com/problems/uneven-temperatures/)
- [Carbon Monoxide Alarm](https://dualitycomfort.com/problems/carbon-monoxide-alarm/)

## Tools
- [Comfort Check](https://dualitycomfort.com/comfort-check/): six-question 0–100 score for a home's system
- [Repair or Replace](https://dualitycomfort.com/repair-or-replace/): age and quote in, an honest read out, no pressure
- [Compare](https://dualitycomfort.com/compare/): vs. national chains, DIY, home warranty
- [Free tools hub](https://dualitycomfort.com/tools/)
- [Seasonal reminders](https://dualitycomfort.com/reminders/): free tune-up and filter reminders by email or calendar file

## Service areas
- [Denver, CO](https://dualitycomfort.com/service-areas/denver/) — 15 min from the shop
- [Lakewood, CO](https://dualitycomfort.com/service-areas/lakewood/) — 20 min from the shop
- [Aurora, CO](https://dualitycomfort.com/service-areas/aurora/) — 25 min from the shop
- [Englewood, CO](https://dualitycomfort.com/service-areas/englewood/) — 5 min from the shop
- [Littleton, CO](https://dualitycomfort.com/service-areas/littleton/) — 12 min from the shop
- [Arvada, CO](https://dualitycomfort.com/service-areas/arvada/) — 30 min from the shop
- [Westminster, CO](https://dualitycomfort.com/service-areas/westminster/) — 30 min from the shop
- [Thornton, CO](https://dualitycomfort.com/service-areas/thornton/) — 35 min from the shop
- [Centennial, CO](https://dualitycomfort.com/service-areas/centennial/) — 12 min from the shop
- [Highlands Ranch, CO](https://dualitycomfort.com/service-areas/highlands-ranch/) — 15 min from the shop
- [Wheat Ridge, CO](https://dualitycomfort.com/service-areas/wheat-ridge/) — 22 min from the shop
- [Golden, CO](https://dualitycomfort.com/service-areas/golden/) — 30 min from the shop
- [Castle Rock, CO](https://dualitycomfort.com/service-areas/castle-rock/) — 30 min from the shop

## Company
- [About](https://dualitycomfort.com/about/)
- [Why Duality](https://dualitycomfort.com/why-duality/)
- [Reviews](https://dualitycomfort.com/reviews/)
- [FAQ](https://dualitycomfort.com/faq/)
- [Financing & rebates](https://dualitycomfort.com/financing/)
- [Blog](https://dualitycomfort.com/blog/)
- [Contact](https://dualitycomfort.com/contact/)

## Optional
- [Full brief](https://dualitycomfort.com/llms-full.txt)
- [For AI assistants](https://dualitycomfort.com/ai/)
- [Sitemap](https://dualitycomfort.com/sitemap-index.xml)
- [Privacy](https://dualitycomfort.com/privacy/)
- [Terms](https://dualitycomfort.com/terms/)