Top Emergency HVAC Services in Union, MO, 63084 | Compare & Call
There are 135 hvac companies server in Union MO
Mid-State Mechanical is a locally owned and operated HVAC contractor proudly serving Lake Saint Louis and the surrounding communities since 2014. Founded by Paul, who brings over 35 years of hands-on ...
Swiss Air Heating & Cooling
Swiss Air Heating & Cooling has been a trusted HVAC contractor serving St. Charles and St. Louis counties since 1989, starting humbly as A&A Services. With an unwavering commitment to integrity and cl...
Stay Cool Climate Control
Stay Cool Climate Control is a family-owned and operated HVAC company proudly serving O'Fallon, MO, and the surrounding communities. Founded in 2018 by Jeremy Wolfe, the business grew from a lifelong ...
Academy Air Heating, Cooling, Plumbing and Electric
Academy Air Heating, Cooling, Plumbing and Electric is a family-owned home services provider proudly serving Hazelwood and the greater St. Louis area. Founded by Terry Silverstein over 40 years ago, t...
WD Heating & Cooling
WD Heating & Cooling is your trusted local HVAC and water heater specialist serving O'Fallon, MO. We specialize in installation, repair, and maintenance for both heating and cooling systems, as well a...
Schraer Heating and Air Conditioning
Schraer Heating and Air Conditioning has been a trusted name in Warrenton, MO, and surrounding areas since 1946, when Omar Schraer began building and installing furnaces locally. In 1994, Gary Scott a...
RiteAir Heating & Cooling is a trusted, full-service HVAC company based in Foristell, MO, serving the St. Louis metro area and surrounding Missouri and Illinois communities. As a certified Trane deale...
Airmerica Heating Cooling
Airmerica Heating Cooling is an independently owned HVAC contractor serving House Springs and the greater St. Louis area with a distinctly hands-on, educational approach. We believe in empowering home...
LCM Heating and Cooling is a trusted local HVAC company serving O'Fallon, MO, and the surrounding communities. We specialize in keeping homes comfortable year-round through expert installation, repair...
Aire Serv of St. Louis
Hi, I'm Dustin, and our team at Aire Serv of St. Louis is proud to serve the Kirkwood community. We operate on a straightforward, powerful principle: if a job’s not done right, we’ll make it right. Th...
Estimated HVAC Service Costs in Union, MO
Frequently Asked Questions
What does the new 14.3 SEER2 minimum efficiency standard mean for my utility bill?
The 2026 SEER2 mandate ensures new systems use at least 14.3 SEER2, which is about 8% more efficient than the old SEER rating for the same number. At Union's average rate of $0.13 per kWh, this directly lowers cooling costs. Pairing a qualifying high-SEER2 system with the active Inflation Reduction Act rebate, which caps at $8,000 for a heat pump, significantly improves the payback period.
My air conditioner stopped on a hot day in Downtown Union—how fast can a technician get here?
For a no-cool emergency, our service vehicle based near Veterans Memorial Park can typically be on US-50 and to most Downtown locations within 5 to 10 minutes. We prioritize these calls to prevent heat buildup and humidity intrusion, which can quickly affect indoor comfort and air quality.
My Ecobee thermostat is showing an E1 alert—what does that mean here?
An Ecobee E1 alert indicates the thermostat is not detecting a call for cooling or heating from your HVAC equipment. In Union, this often points to a safety lockout from a clogged condensate drain line due to high humidity, a tripped float switch, or a failed control board. It's a diagnostic signal prompting a check of these local failure points before a minor issue causes a compressor shutdown.
Why do most central air units in Union need more maintenance as they get older?
A typical Union home was built around 1996, making its original HVAC system roughly 30 years old. At this age, seals degrade and components like contactors and capacitors wear out. Our humid continental climate specifically accelerates condensate drain line clogs; the constant high moisture promotes algae and mold growth inside the drain pan and PVC line, which is the most common service call we see.
Can my existing ductwork handle better air filters for our ozone and pollen issues?
Upgrading filtration helps address May pollen peaks and ground-level ozone risks by capturing finer particles. Your galvanized sheet metal ducts with external wrap are generally robust, but adding a deep-pleat MERV-13 filter can raise static pressure. A technician should measure static pressure to ensure your blower motor isn't overworked, which might require adjusting fan speed or slightly enlarging the filter grille.
What are the permit and safety rules for a new A/C installation in Union now?
All HVAC replacements in Union require a permit from the City of Union Building Department, which ensures compliance with current mechanical and electrical codes. As of 2026, installations using A2L refrigerants like R-454B must follow specific EPA Section 608 safety standards for mildly flammable refrigerants, including leak detection, area ventilation, and clearly marked service ports. Your contractor must provide documentation of this certification.
Is switching from my gas furnace to a heat pump practical for a Union winter?
Modern cold-climate heat pumps are effective for Union's winters, but supplementing with your existing gas furnace during the coldest hours below 15°F can optimize cost. To maximize savings, use the heat pump during off-peak hours and set your thermostat to minimize operation during Ameren Missouri's peak demand period from 2 PM to 7 PM, when electricity rates are highest.
How well does a modern air conditioner handle our summer heat above 90 degrees?
Systems are sized for Union's 92°F design temperature, meaning they are engineered to maintain a 20-degree delta T from indoor air at that specific outdoor condition. When temperatures exceed 92°F, the system will run longer cycles to meet the load. The newer R-454B refrigerant standard for 2026 offers stable pressure and efficient heat transfer even during these extended high-ambient operations.
