HVAC replacement in Prince William County, VA

Prince William County's permit rules are a little different from its neighbors': some like-for-like electric replacements don't need a permit at all, while gas furnace replacements do. That makes it especially worth knowing what your quote includes.

Permits in Prince William County

Prince William County's Building Development Division says no permit is needed to replace an electric furnace, heat pump or air conditioning condensing unit with the same type of unit in the same location.

A permit is required for alterations to the mechanical system and for replacing a gas or oil furnace. New electrical circuits also need a permit. Inspections are scheduled through the county's ePortal or by phone.

The county issues permits for Occoquan, Haymarket and Quantico, but not for the cities of Manassas and Manassas Park or the Town of Dumfries. The City of Manassas issues its own building and trade permits.

If you're switching system types (for example, from a gas furnace to a heat pump) or changing ducts or circuits, ask the contractor which permits apply and whether they're included.

Utilities

• Electricity: Dominion Energy Virginia or NOVEC, which serves more than 84,000 customers in the county.
• Natural gas: Washington Gas serves most gas customers; Columbia Gas of Virginia serves some areas.

Your utility matters for rebates, and for whether a heat pump, gas furnace or dual-fuel system makes the most sense for your bills.

Rebates and tax credits (as of November 2026)

• Federal tax credit: the 25C energy efficient home improvement credit, which covered heat pumps, central air and furnaces, ended for equipment placed in service after December 31, 2025. Systems installed in 2026 don’t qualify.
• Virginia home energy rebates: the state’s federally funded HEAR and HOMES programs are not open yet. Virginia Energy says launch depends on federal approval, and plans call for up to $8,000 toward a heat pump for income-qualified households. Work started before launch may not qualify.
• Washington Gas: customers can save up to $800 through the Home Energy Savings Program. In Virginia, the work must be done by a contractor in the program’s network.
• Columbia Gas of Virginia: up to $500 for a gas furnace rated 90% AFUE or higher in an existing home heated mainly by gas, bought and installed in 2026. Apply within 120 days or by January 31, 2027, whichever comes first. Funds are first come, first served.
• Dominion Energy Virginia: no rebate is currently listed for central heat pumps or air conditioners. Dominion offers smart thermostat rewards and an income- and age-qualifying program.

Rebate terms change often. Confirm the current terms with the utility before you buy.

What replacement costs here

In real Northern Virginia quotes we’ve reviewed, a complete furnace and air conditioner or dual-fuel replacement ran from $12,576 to $21,594. See what drives the price, and why quotes for the same house differ.

For residential jobs between $1,000 and $10,000, the county also requires a Prince William Home Improvement Contractor license, a bond and a county business license, on top of the Virginia contractor license. Most full replacements cost more than $10,000, but it's a useful check on smaller jobs.

Before you sign

• Check the contractor’s Virginia license on the DPOR license lookup. HVAC work falls under the HVA specialty, and gas work under the GFC specialty.
• Make sure the size comes from a Manual J load calculation, not from the old unit.
• Get exact model numbers, and confirm whether the refrigerant lines and return ducts are included.
• Confirm the permit, inspection and labor warranty are in writing.

How 1Stop helps in Prince William County

1Stop is an independent service based in Ashburn. We don’t install systems or work for any contractor. A Comfort Consultant visits your home, runs a Manual J load calculation and writes one scope of work. Licensed, insured local contractors bid on that same scope, and you compare every bid side by side. It’s free for homeowners. See a sample comparison.