Key Heating & Air Conditioning

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Claim This BusinessAbout Key Heating & Air Conditioning
Key Heating & Air Conditioning serves Exeter and the surrounding New Hampshire communities as a full-service HVAC contractor backed by 706 client reviews that collectively earn the business a 4.8-star rating. The company maintains around-the-clock availability every day of the week, enabling dispatch for heating and cooling emergencies regardless of when problems arise. Technicians with experience across residential systems routinely handle calls spanning from straightforward maintenance visits to complex diagnostic challenges involving older equipment. Customers in Exeter and nearby towns regularly describe reaching the company during weekends or late evenings and receiving same-day response.
Specific equipment installations highlighted in recent projects include ductless mini-split configurations that require careful positioning of refrigerant lines and electrical connections. The company maintains service agreements for ongoing maintenance and offers member perks such as waiving diagnostic fees on scheduled visits. Emergency visits booked outside normal business hours address furnace failures and system malfunctions that cannot wait until the following day, a capability several reviewers specifically required after competing contractors failed to respond.
Reviewers consistently mention individual technicians by name. Jonathan DeSisto guided a homeowner through extensive documentation requirements during a multi-unit mini-split installation, while Seth, Will, and Max composed the installation crew praised for concealing exposed line sets beneath roof overhangs for a clean visual result. Peter handled a Saturday night after-hours furnace emergency for a new customer who had not previously contracted with the company, arriving on time and explaining repair options. Michael resolved an urgent situation by assessing the issue, implementing a temporary repair, and ordering components needed for a lasting solution.
What Customers Say
Seven verified reviewers awarded 5-star ratings and described specific outcomes. Three customers specifically cited emergency same-day arrivals, including one Saturday night furnace failure and another handled via last-minute cancellation. No negative reviews appeared in the sample set. Technicians named across multiple positive reviews include Peter, Michael, and Jonathan DeSisto, suggesting consistent service delivery across different teams.
Working Hours
| Sunday | Open 24 hours |
| Monday | Open 24 hours |
| Tuesday | Open 24 hours |
| Wednesday | Open 24 hours |
| Thursday | Open 24 hours |
| FridayToday | Open 24 hours |
| Saturday | Open 24 hours |
Services
Heating System Repair
Diagnosis and repair of furnaces, boilers, and heating equipment failing to produce adequate warmth.
Cooling System Service
Air conditioning maintenance, refrigerant recharge, and component replacement for cooling systems.
Ductless Mini-Split Installation
Installation of ductless mini-split heat pumps including mounting indoor units and routing refrigerant lines.
Preventive Maintenance
Seasonal tune-ups designed to maintain system efficiency and extend equipment lifespan.
Emergency HVAC Service
Round-the-clock dispatch for heating and cooling emergencies requiring immediate attention.
System Diagnostics
Assessment of system performance to identify malfunction causes and recommend appropriate repairs.