Replacing Gas Heat with High-Efficiency Heat Pumps: A Whole-Home HVAC Upgrade in Concord, MA

Why Homeowners Are Upgrading from Gas to Electric Heating

Massachusetts homeowners are increasingly replacing fossil-fuel heating systems with high-efficiency electric heat pumps. Drivers include:

• Rising natural gas costs

• State and federal incentives (Mass Save rebates, tax credits)

• Electrification and decarbonization goals

• Desire for year-round comfort with one system

Recently, a Concord, MA homeowner worked with Denommee Plumbing, HVAC & Electric to complete a full gas-to-electric heat pump conversion for their 1954-built, 4,177 sq. ft. single-family home.

Let’s explore the scope of this project, why mixed ducted/ductless systems were chosen, and how Denommee delivered outstanding results.

Project Overview: Whole-Home Heat Pump Conversion in Concord, MA

The homeowners wanted to eliminate reliance on natural gas for heating, improve energy efficiency, and modernize their HVAC system. Their goals included:

• Replacing an aging gas boiler and AC system

• Improving comfort and zoning control

• Maximizing available rebates and tax credits

• Future-proofing their home with all-electric heating and cooling

Denommee’s solution: a whole-home, mixed ducted and ductless heat pump installation, qualifying for a $10,000 Mass Save rebate and federal tax credits.

Equipment Installed: High-Performance Heat Pump Systems

Main System: 3.5 Ton, 3-Zone Mitsubishi Hyper Heat

• Outdoor Unit: Mitsubishi MXZ-SM42NAMHZ2 (Hyper Heat Inverter)

• Indoor Units:

  • SVZ-KP24NA (Ducted Air Handler – Attic)

  • MFZ-KJ12NA (Low Wall Console)

  • MFZ-KJ15NA (Low Wall Console)

• Branch Box: PACMKA32BC for multi-head zoning

• Controls: MHK2 wall thermostats & Kumo Cloud Wi-Fi adapters

• Performance:

  • High Heat Output: 48,000 BTU @ 47°F and 17°F

  • Maintains 37,895 BTU even at -13°F

Rear Addition System: 2.0 Ton Custom Comfort Ducted Heat Pump

• Outdoor Unit: CCOXHA24V24HP

• Indoor Unit: Multi-positional ECM Air Handler with 4-stage blower

• Backup Heat: 5kW strip heater for supplemental heating

• Thermostat: Ecobee Smart Thermostat Pro

Installation Scope & Technical Details

Denommee’s expert in-house team completed a comprehensive scope of work:

• Removed existing gas furnace, boiler, and AC system

• Installed (2) outdoor heat pump condensers on leveled, sound-absorbing pads

• Installed (4) indoor units with line sets, drainpipes, wiring, and wall insulation

• Housed exterior line sets in white line-hide for a clean finish

• Nitrogen pressure tested, vacuumed lines to <500 microns, charged with R-410A

• Connected and commissioned all controls, including Kumo Cloud Wi-Fi access

For ducted zones, Denommee fabricated and installed new ductwork systems:

• Basement Scope: New 2.0 ton galvanized duct system

• Fully sealed, insulated trunks and branches

• Installed 5-6 supply registers and 4 return vents

• Accessory installation: hangers, vibration blocks, drains, grills, diffusers

Electrical upgrades were performed by Denommee’s licensed electricians:

• Installed new 2-pole breakers and dedicated feeds for both heat pump systems

• Added switched attic lighting and service outlets for maintenance access

• Provided power for backup strip heating elements

The Results: Year-Round Comfort, Efficiency & Incentives

By replacing their outdated gas heating system with a modern heat pump solution, the Concord homeowners now enjoy:

• Consistent, efficient heating even on sub-zero winter days

• Whole-home air conditioning with zoning control

• Reduced energy bills and carbon footprint

• $10,000 Mass Save instant rebate

• Federal tax credits up to $2,000

• Future-proofed HVAC infrastructure aligned with Massachusetts electrification goals

Why Mixed Ducted & Ductless Systems Work for Homes Like This

Older New England homes often have design constraints that make fully ducted solutions challenging. Denommee’s mixed approach delivers:

• Ducted air handlers for primary living spaces (maintaining traditional air distribution)

• Ductless low wall consoles for hard-to-duct areas like additions or sunrooms

• Flexibility for future expansions or changes

• Maximum comfort and efficiency while minimizing renovation disruption

This strategic design ensures even temperatures, quiet operation, and optimal energy use—especially important for larger homes like this 4,177 sq. ft. Concord residence.

Denommee’s Value for Homeowners Considering Heat Pump Upgrades

Denommee Plumbing, HVAC & Electric brings unique advantages for homeowners considering gas-to-electric HVAC conversions:

✅ Mass Save HPIN Contractor

• Ensures compliance with program standards

• Facilitates rebate paperwork and verification

✅ Abode Energy Approved Installer

• Supports Municipal Light Plant (MLP) customers

• Local expertise in MLP electrification incentives

✅ Mitsubishi Elite Diamond Contractor

• Factory-authorized installations with extended warranties

• Advanced system design expertise for ducted and ductless applications

✅ Bosch Home Comfort Platinum-Tier PRO Contractor & Bryant Partner

• Flexibility in system selection for various home needs and budgets

✅ In-House Electricians & Plumbers

• Seamless coordination for comprehensive HVAC upgrades

• Eliminates delays from subcontractors

• Ensures code-compliant, safe installations

✅ Transparent Flat-Rate Pricing

• Upfront, scope-based quotes

• No hourly surprises

Comprehensive Support with Denommee’s Peace of Mind Program

Beyond installation, Denommee supports homeowners with:

• Annual HVAC safety & performance assessments

• Plumbing and electrical system evaluations

• Priority scheduling & repair discounts

• Comprehensive Peace of Mind Service Program Memberships

This proactive approach ensures systems like the one installed in Concord continue to perform at peak efficiency for years to come.

Denommee’s Service Areas

We proudly serve:

• Concord, Acton, Lexington, Belmont, Bedford, Burlington

• Westford, Groton, Chelmsford, Nashua, Tewksbury, Woburn

• Arlington, Dracut, Littleton, and surrounding communities

Ready to Electrify Your Home’s HVAC System?

If you’re exploring gas-to-electric heat pump upgrades, Denommee Plumbing, HVAC & Electric offers the expertise, credentials, and service excellence you need.

📱 Text “Heat Pump Quote” to 857-226-9140 to schedule your no-cost, no-pressure consultation today.