What to check when your heating or cooling stops. What to ask about a repair quote. Where to find help with broken equipment in Loudoun.
When a breakdown needs more than a service visit
A furnace that stops heating needs a different response from a carbon-monoxide alarm. Loudoun County Combined Fire and Rescue says to move immediately to fresh air if a CO alarm sounds. Call for help from there. Stay out until emergency personnel say you can return. Waiting indoors for an HVAC technician does not keep you safe.
The county explains that damaged or misused fuel-burning heating equipment can produce carbon monoxide. You cannot smell or see it. Take an alarm seriously even when the furnace seems to run normally. The county also offers home safety visits to check whether your smoke and CO alarms work. These visits also check that the alarms are in the right places. They do not replace a technician's work on the furnace.
If there is no alarm or other immediate hazard, write down what happened before the equipment stopped. Which rooms lost heat or cooling? What did the thermostat display? Does the problem keep returning? Give the technician that history instead of guessing which part failed.
Source: Loudoun County Combined Fire and Rescue System, carbon-monoxide safety guidance reproduced in the County Administrator's Report, published 2023-02-08; no separate effective date stated. Gathered 2026-09-23.
What the technician should establish before replacing parts
“Not cooling” describes a symptom. The U.S. Department of Energy lists several possible causes. These include a clogged filter, incorrect thermostat settings, refrigerant problems, blocked drains and worn electrical controls. Each calls for a different repair. The list does not tell you which faults happen most often in Loudoun. We could not verify a county dataset of repair diagnoses.
Start by checking the thermostat settings, following the equipment manufacturer's instructions. Check the filter the same way. Loudoun's HVAC safety guidance warns that dirty filters can damage equipment. It recommends that a licensed contractor check for refrigerant and carbon-monoxide leaks. Leave refrigerant work to the technician. Leave internal electrical checks to them too.
Ask the technician what they tested. Ask what failed. Have them explain how the proposed work will solve your problem. Ask them to name the failed part in the service record. Get the relevant test results recorded too. If the system still leaves rooms uncomfortable, ask what remains unresolved. A replaced part may not be a complete fix.
DOE's cooling guidance warns that problems happening together can mislead a technician about how much refrigerant is in the system. A restriction can look like a refrigerant charge problem. Adding refrigerant without finding the cause can leave the original fault in place.
Source: U.S. Department of Energy, Home Cooling 101, June 2014 publication, and Measure Guideline: Air Conditioner Diagnostics, Maintenance, and Replacement, March 2013 publication; Loudoun County, June 2021 Newsletter, HVAC safety guidance. These guidance documents state no separate effective dates. Gathered 2026-09-23.
A refrigerant problem does not automatically mean a new system
If the technician proposes a refrigerant recharge, ask whether they found a leak. Ask whether the price includes fixing it. EPA recommends finding and repairing leaks instead of repeatedly topping up the system. Ask for the refrigerant type on the invoice. Have the amount added recorded too. That helps the next technician understand what happened.
The person handling refrigerant should hold EPA Section 608 certification. That covers refrigerant work. The contractor licensing rules on the Loudoun HVAC page still apply separately.
A refrigerant phaseout alone does not mean you need a whole new system. EPA says existing systems using higher-global-warming-potential refrigerants can still be repaired. That includes changing major components. Its homeowner guidance specifically allows replacing a faulty component with a similar R-410A component. EPA also says you need not replace existing R-22 equipment solely because of the phaseout. Nor must you convert it for that reason.
That does not guarantee you can get the right part. Nor does it guarantee a repair will be worth the cost. Before agreeing to a replacement, ask which part failed. Ask how it could be repaired. Ask why the contractor recommends spending more.
Source: U.S. Environmental Protection Agency, Homeowners and Consumers: Frequently Asked Questions, Purchasing and Repairing Home Air-Conditioners or Heat Pumps, and Frequent Questions on the Phasedown of Hydrofluorocarbons, current guidance; no overall effective dates stated. Gathered 2026-09-23.
When the repair grows into permitted work
Virginia lets the building official treat work as minor and ordinary if it does not harm public health or general safety. That rule does not list every HVAC part repair as exempt. Calling the work a “service call” does not settle whether you need a permit.
Ask what will actually change. Replacing a failed component within existing equipment differs from changing fuel piping, altering a circuit or adding ducts. The state generally requires permits for changes to mechanical, electrical and fuel-supply systems. Its exemptions still apply.
Loudoun Building and Development handles the local permit process described on the county HVAC page. If another fault makes the job bigger, get the revised work written down. Have it name who will settle whether you need a permit. Have it name who will arrange any required inspections too. Even exempt work must meet the applicable code. In a special flood hazard area, Virginia lets the building official require permits even for otherwise exempt work.
Source: Virginia Department of Housing and Community Development, 13VAC5-63-80, Section 108, especially the minor-and-ordinary-work provisions and exceptions, last amended effective 2024-01-18. Gathered 2026-09-23.
What the repair quote should cost—and explain
We could not find a primary source tracking residential HVAC repair prices specifically for Loudoun. We cannot give you a supported local range for a diagnostic visit, replacement part or emergency surcharge. The county permit fees do not tell you what those charges will be.
Before you approve work, ask whether the diagnostic charge counts towards the repair price. Ask whether the price includes labour. Check whether it covers return visits too. Ask what happens if the proposed part does not solve your problem. Have the contractor explain parts cover separately from labour cover in any warranty.
Virginia's residential contracting rules require a signed written contract before work starts or you pay. There are exclusions for routine maintenance or service contracts and specified subcontractors. Required terms include the work, price basis, dates, payment schedule and contractor credentials. Any changes to cost, materials, scope or estimated completion date must be put in writing. All parties must sign them.
If a repair becomes a larger job, get the added work agreed in writing. Keep the diagnosis, approved scope, invoice and warranty terms together. If the fault returns, they show what the contractor promised.
Source: Virginia Board for Contractors, 18VAC50-22-260, Filing of charges; prohibited acts, contract, change-order and warranty provisions, last amended effective 2025-09-01. Gathered 2026-09-23.
Help when the household cannot fund the repair
Loudoun's Information and Referral program covers fuel, cooling and crisis assistance, as well as home repairs. Each type of help meets a different need. Help paying an energy bill does not necessarily cover the contractor fixing your equipment.
Virginia's Energy Assistance Program says crisis support may cover heating equipment repairs or replacement during a household heating emergency. That includes having no heat or unsafe equipment. Cooling support may cover central air-conditioner or heat-pump repairs. Income rules apply. You must apply within seasonal windows. There are additional household requirements too. Being eligible does not guarantee that a particular invoice will be paid.
Loudoun also lists Senior Cool Care in its summer activity guide. It offers fans and limited cooling help to eligible older residents. That can help you feel more comfortable straight away. The listing does not promise a central HVAC repair. Before taking on a bill you need help paying, check which program can cover the proposed work. Check whether it must approve the work first.
Source: Loudoun County Family Services, Information and Referral Request Form, undated; Virginia Department of Social Services, Energy Assistance Program, undated current guidance; Loudoun County Parks, Recreation and Community Services, 2026 Summer Activity Guide, page 52, summer 2026 program listing. No separate effective dates stated. Gathered 2026-09-23.