Pick one and we will keep it short. Three taps and you are done.
We run calls seven days a week, and we answer the phone around the clock.
Last step. We will call you back to confirm the window.
An emergency deserves a person, not a web form sitting in an inbox. Call the shop and we pick up.
No heat, no water, an active leak, or a backed up main. These move to the front of the line, day or night, weekend or holiday.
Your request is in and somebody will call you back to confirm a window. Here is what we have:
Most no-heat calls end in a part and a relight the same day. The ones that do not are usually about venting, which is also the step a cheap changeout skips. Call (703) 491-6542. Office hours are 7 to 5, and after that the phone goes to Jon rather than a voicemail box.
A furnace quits on the coldest night because that is the night it has worked hardest. Before you brace for a replacement quote, know that most of what we find is a part, and we would rather hand you one of those than a proposal. What usually turns out to be wrong:
Read this twice, because nearly every heating page says the opposite. In a staff draft rulemaking notice on residential gas furnaces and boilers dated 31 July 2019, Consumer Product Safety Commission staff reported that most CO incidents they reviewed involved appliances 15 years old or less, average age 9.6 years. Staff called that equipment modern, fitted with the latest safety devices, and said those devices were not capable of protecting against CO exposure.
The same analysis ranked failure modes across 83 cases. Disconnected or breached vents, chimneys or heat exchangers led at 19.3 percent, 16 of 83. Blocked vents, air intakes, heat exchangers or chimneys followed at 18.1 percent. Those two venting categories together are 31 of 83, or 37 percent. It is a staff analysis, not an official statistic. It is also a good reason to put a light up the flue of a nine-year-old furnace.
Section 113.3.1 of the Virginia Uniform Statewide Building Code is a state amendment rather than base model code, and it is the most useful paragraph on this page. Replace a fuel-burning appliance in an existing house and an inspection has to confirm two things about the vent or chimney it connects to: that it is sized per the residential code, and that it is clean, free of obstruction, defects and deterioration, and in operable condition. Where the building department does not inspect it, whoever did the work must certify in writing to the building official that both are met. Read it at law.lis.virginia.gov. A furnace from the nineties vented into a masonry chimney does not automatically suit a condensing replacement, and that case is why the section exists.
Virginia Residential Code Section M1401.3 requires heating equipment to be sized per ACCA Manual S from building loads calculated per ACCA Manual J, and both standards are written into the building code by reference. Reading the input rating off the old data plate and ordering the same number is not what the code asks for. It also carries forward whatever mistake was made last time, possibly decades ago.
Combustion air is the calculation nobody warns you about. The standard indoor method in the Virginia Fuel Gas Code asks for 50 cubic feet of room volume per 1,000 Btu/h of input, so an 80,000 Btu/h furnace wants 4,000 cubic feet around it. A closet under the stairs has nothing like that, so outside air comes in through permanent openings sized at 1 square inch per 4,000 Btu/h through vertical ducts.
| Item | What the code asks for | Citation |
|---|---|---|
| Existing flue or chimney | Verified as correctly sized per the residential code and as clean, unobstructed and in operable condition. If the building department does not inspect it, the installer certifies it in writing to the building official. | USBC Section 113.3.1 |
| Equipment size | Selected per ACCA Manual S from a building load calculated per ACCA Manual J, or another approved method. Manual J-16 and Manual S-14 are incorporated into the USBC by reference. | VRC Section M1401.3 |
| Combustion air | By the standard indoor method, 50 cubic feet of room volume per 1,000 Btu/h of appliance input. Short of that, outside air through permanent openings, no opening dimension under 3 inches. | Fuel Gas Code 304.5.1, 304.6 |
| Sediment trap | A capped nipple set vertically in the bottom of a tee, downstream of the appliance shutoff and as close to the appliance inlet as practical, unless the appliance has one built in. | Fuel Gas Code 408.4 |
| Appliance gas shutoff | In the same room as the furnace, within 6 feet of it, upstream of the connector, and accessible. | Fuel Gas Code 409.5.1 |
| Gas piping test | Pressure tested at not less than one and a half times maximum working pressure and never less than 3 psig. In a single-family house the test runs at least 10 minutes, and any drop on the gauge counts as a leak. | Fuel Gas Code 406.1, 406.4, 406.5 |
| Electrical supply | Central heating equipment gets an individual branch circuit. The outdoor condensing unit and directly associated accessories may share it; the basement lights may not. | VRC Section E3703.1 |
| Cooling coil condensate | Drain not less than 3/4 inch, sloped at least 1/8 inch per foot, and a secondary pan or overflow protection wherever a stoppage would damage the building. | VRC Sections M1411.3, M1411.3.1 |
Two confident versions of this circulate and both are wrong. Federal minimums sit in 10 CFR 430.32. Non-weatherized gas furnaces built today must hit 80.0 percent AFUE, and the same section sets 95.0 percent AFUE for units manufactured on and after 18 December 2028, which in practice means condensing equipment. Note the word manufactured. It is not an install date, so an 80 percent furnace built before that day can still be sold and fitted afterward. Weatherized furnaces stay at 81.0 percent, and the increase does not reach boilers or oil furnaces.
Then there is the litigation. In American Gas Association v. Department of Energy, the DC Circuit upheld the furnace standards on 4 November 2025. On 8 June 2026 the Supreme Court granted review, vacated that judgment and sent the case back to the DC Circuit without ruling on the merits. So the standard was neither upheld nor struck down. Gas industry groups separately petitioned the department in February 2026 to push the date to 1 January 2030 at the earliest, and it has not acted. The December 2028 date is still on the books, and it could still move. Anyone telling you to buy now and beat a ban is selling.
No federal rule makes you replace a working furnace, and the Environmental Protection Agency publishes no age and no repair-cost percentage at which replacement wins. The figures that do exist give a range and a nudge. ENERGY STAR suggests considering replacement once a furnace is more than 15 years old, which is a shopping trigger rather than a prediction. InterNACHI's chart puts a furnace at 15 to 25 years and warns its own numbers are a general guideline, not a guarantee or warranty. The Department of Energy says 15 to 30 years. Two credible sources, two different ranges, and a single number rounds away the honest part.
Here we part company with the usual script. We went looking for a government or standards source saying a cracked heat exchanger must mean a new furnace, and for one blaming the cracking on metal fatigue from thermal cycling. Neither exists. Those are trade and manufacturer positions dressed up as settled engineering.
What is documented is narrower and still serious. CPSC lists compromised heat exchangers among the routes combustion products take into the living space, and InterNACHI puts a heat exchanger at 10 to 15 years, shorter than the 15 to 25 it gives the furnace around it. A confirmed breach is a safety condition. We shut the unit down and show you what we found, and in practice that ends in a replacement. We just will not claim a federal agency ordered it.
Virginia splits trade licences narrowly. Under 18VAC50-22-20 the plumbing classification expressly does not provide for gas piping, and neither does the HVAC classification. Gas piping needs its own gas fitting classification, and a general residential building licence covers none of plumbing, HVAC, electrical or gas fitting. That is why extending a gas line can put a second contractor in your driveway.
1 Stop Mechanical carries plumbing, HVAC and gas fitting on one Virginia Class A licence, number 2705131990, so the furnace, the gas connection and the flue stay with one crew. The board also requires a master tradesman to stand behind each classification a company holds.
A furnace is equipment regulated by the building code, so replacing one takes a permit. USBC Section 108.1 covers the situation you are probably in if you are reading this in February: an application for emergency equipment replacement may be filed by the end of the first working day after work starts. A dead furnace does not wait for a counter to open. Filing is our job, not yours. Prince William County inspections get scheduled by 3 p.m. the working day before.
ENERGY STAR's heating and cooling guide is blunt: dirt and neglect are the top causes of heating and cooling system inefficiency and failure. Its filter instruction is to check monthly and change if dirty, or at least every three months. CPSC calls an annual inspection and service the first line of defense against this silent killer. What nobody can tell you is how many years a tune-up adds, because no source puts a number on it, and we will not invent one. See maintenance and tune-ups.
If the furnace is near the end, the neighbouring pages matter. Heat pumps do both jobs in one machine, and dual fuel keeps the furnace for the worst of January. Boilers are a different animal with a longer expected life. If your cooling coil sits on the furnace, air conditioning belongs in the same conversation: ENERGY STAR warns that a new efficient condenser tied to an old furnace and blower will not reach its rated efficiency.
One call covers plumbing and HVAC. Talk to somebody who has been doing this for decades.
