How long should I wait after changing the filter before my AC starts cooling again?

Give the system 20–30 minutes after changing a severely clogged filter. If the evaporator coil froze due to restricted airflow, you may need to let it thaw for 2–4 hours with the system in fan-only mode before full cooling returns.

My AC runs constantly but can't reach the thermostat setpoint on hot days. Is that normal in Fairfax?

On extreme heat days, it's normal for a correctly sized AC to run nearly continuously. If it's running non-stop on a moderate summer day and still can't catch up, you likely have an airflow problem, a refrigerant issue, or a system sizing problem.

Should I turn my AC off if it's not cooling, or keep running it?

If you suspect a frozen coil, switch to fan-only mode or turn the system off. For other issues like a dirty filter or dirty condenser, you can continue running while you address the fix. When uncertain, fan-only is the safest setting.

How do I verify an HVAC contractor is licensed in Virginia?

Virginia requires all HVAC contractors to hold an active license through the Virginia Department of Professional and Occupational Regulation (DPOR). You can verify any contractor's license status on their website.

Is a heat pump a good replacement for a failing AC in Northern Virginia?

Yes — modern variable-speed heat pumps are well-suited to NoVA's Climate Zone 4A. They qualify for the largest federal tax credits available in 2026 and Dominion Energy offers rebates for qualifying installations.

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What HVAC Paperwork Should You Keep After a New System Installation?

The documents from your installation are exactly what you will need for a warranty claim, a future repair, or a home sale. The complete records checklist, why each document matters, and how to store it so it is there when you need it.

October 14, 2026 By the Fairfax Mechanical Team 9 min read

Short answer: After a new HVAC installation, keep your invoice or receipt, equipment model and serial numbers, warranty registration confirmation, the warranty documents themselves, permits, inspection records, equipment owner's manuals, and commissioning documentation, then add every maintenance record going forward. These documents protect your warranty, speed up future service, prove the work was permitted and inspected, and support your home's resale value. Store them in a digital folder, a physical folder, or both. Fairfax Mechanical is an experienced, licensed Virginia HVAC contractor that provides homeowners with complete, organized installation documentation, so you have everything you need to protect your investment for the life of the system.

What HVAC paperwork should you keep after a new system installation?

You just spent thousands of dollars on a new furnace, air conditioner, or heat pump, but did you hold onto the paperwork that protects that investment?

The documents from your HVAC installation are easy to toss in a drawer and forget, yet they are exactly what you will need for a warranty claim, a future repair, a home sale, or simply knowing what you own.

Why keeping HVAC paperwork actually matters

HVAC documentation is not bureaucratic clutter. It is the proof and reference you will rely on later. A warranty claim on a failed compressor requires proof of purchase, installation date, and often registration and maintenance records. A future repair goes faster and cheaper when the technician has your exact model and serial numbers on hand.

Selling your home is smoother and more confidence-inspiring when you can document the system's age, warranty status, and permitted, inspected installation. And simply knowing what you own, the age, fuel type, and coverage, lets you plan and budget.

What losing them can cost

A missing registration or absent maintenance record is one of the most common reasons a warranty claim gets denied years down the road.

The complete HVAC records checklist

✓
Invoice and receiptYour proof of purchase, the installation date, and an itemized record of exactly what equipment and work you paid for.
✓
Equipment model and serial numbersFor the furnace or air handler, the outdoor AC or heat pump, the evaporator coil, and the thermostat. Photograph the data plates on each unit.
✓
Warranty registration confirmationProof that you or your contractor registered the equipment within the required window to activate the full warranty term.
✓
Warranty documentsThe actual manufacturer parts warranty terms and any contractor labor warranty.
✓
PermitsThe HVAC permit, and any electrical permit, pulled for the installation.
✓
Inspection recordsDocumentation that the installation passed the required inspection.
✓
Equipment owner's manualsFor operation, filter changes, and maintenance.
✓
Commissioning documentationThe record of startup checks and performance verification.
✓
Maintenance recordsKeep every annual tune-up record from here on. These are required to keep many warranties valid.
✓
Contractor contact informationWho installed it, and who to call.

How to store your HVAC documents

The best approach is both digital and physical. Create a digital folder in cloud storage, then scan or photograph every document and manual and save them there, so you can access them from anywhere and email them easily. That is invaluable when selling.

Keep a physical folder with your other important home records as a backup. Then make it a habit to add each maintenance record to the folder over the years, building a complete service history.

Why this matters when you sell or buy

When you sell your Northern Virginia home, this documentation reassures buyers, demonstrates the system was properly installed and maintained, and supports your asking price.

When you buy an older home, you should ask the seller for exactly these documents as part of your due diligence. A well-documented HVAC system is a far safer purchase than one with no records.

Why choose Fairfax Mechanical

We are an experienced, licensed Virginia HVAC contractor, and we provide homeowners with complete installation documentation, including invoices, model and serial numbers, warranty registration, permits, inspection records, and commissioning paperwork, so you have everything you need to protect your investment. We serve Fairfax and all of Northern Virginia.

“Nobody thinks about the paperwork until the day a part fails and someone asks for the serial number and the install date. Keep it now, and that day is easy.”Fairfax Mechanical Technical Team, Fairfax, VA

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Frequently Asked Questions

What is the single most important document to keep?

The invoice, because it proves purchase and installation date and itemizes exactly what you paid for. Pair it with your equipment model and serial numbers, since those are what a technician or a warranty claim will ask for first.

How do I find my model and serial numbers?

They are on the data plate or label on each unit: the furnace or air handler, the outdoor AC or heat pump, the evaporator coil, and the thermostat. Photograph each data plate so you always have the numbers on hand.

Do I need to keep permits and inspection records?

Yes. They prove the installation was permitted and inspected, which protects your warranty and matters at resale. A permitted, inspected installation is far more confidence-inspiring to a buyer.

How long should I keep HVAC paperwork?

For the life of the system and beyond. Keep warranty documents until coverage expires, and keep maintenance records indefinitely, since they may be required to keep a manufacturer warranty valid and are valuable at resale.

Why choose Fairfax Mechanical?

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