Some HVAC Problems Need a Safety Call First
Leave the house and call Washington Gas on 844-WASHGAS from outside. Not us. A gas leak is the utility's emergency, and they come out free of charge at any hour.
Do not turn anything on or off on the way out, including lights, and do not use the phone indoors. Once the utility has shut off and made the line safe, they will red-tag whatever appliance was leaking. That tag is what we work from. Call us after that and we will look at the appliance itself.
Get everyone outside, then call 911 from outside. If anyone has a headache, nausea or is confused, say so on the call. Carbon monoxide is not something to diagnose from indoors.
The fire department will meter the house and tell you what level they found. After that the source has to be found, which usually means a cracked heat exchanger, a blocked flue or a water heater venting back into the room. We can test the appliance and its draft. We cannot tell you the house is safe to sleep in. That is the fire department's call, not ours.
Usually not, if you turn the cooling off at the thermostat. The water is condensate that has stopped draining, and once the coil stops making more, the leak stops.
What decides urgency is where the water is going. A unit sitting in a basement with a floor drain can wait until morning. One in an attic or a closet above finished ceilings cannot, because the next thing to show up is a stain on the plaster below. Turn the system off, look at the ceiling underneath, and let us know what you see.
Yes, turn it off at the thermostat. An outdoor unit running with no indoor airflow builds pressure and ice, and every extra hour of that makes the eventual repair bigger.
Most of the time this is the indoor blower, its capacitor or a control board, and none of those get better by running. Occasionally it is something small, like a tripped condensate safety switch doing exactly what it is designed to do. Leave it off, change the filter if it is dirty, and schedule a visit.
Cooling that has stopped: AC repair in Cheverly.
A Good HVAC Service Visit Should Leave You With Clear Answers
Yes. Ask for it during the visit and the technician writes down what was measured, what the reading was, and what the part is. You own that paperwork whether or not you go ahead with the work.
This matters more than it sounds. A diagnosis that says "compressor is bad" tells a second company nothing. One that gives the capacitor's rated microfarads against what it measured, or the pressures either side of a restriction, can be checked by anyone. If a company will not write down what it measured, that is worth knowing before you spend.
Yes. The diagnostic is $75 and it covers the technician's time finding the fault. It is waived when you schedule the repair, and it stands when you do not.
An after-hours, Sunday or rooftop call is $169 and that one is not waived, because somebody is coming out at a time nobody is scheduled to work. A replacement estimate is a different case. If your system is already being replaced and you want a quote, that visit is free, because nothing is being diagnosed.
On a new system you get a written, binding estimate before anything is ordered. The number on it is the number you pay unless you change the scope. On a repair, written pricing comes on request.
The distinction is worth asking any contractor about, because the word "estimate" does a lot of quiet work in this trade. A binding estimate means the company has already worked out what the job needs. A non-binding one means the price can move once the work starts, and you find out at the end.
Someone over 18 needs to be there at the start and the end. The start is where the technician shows you what they found. The end is where you see what was done and sign it off.
The hours in between are yours. On a full system change there is also an inspection to think about, and the county inspector needs access, which is a second appointment on a different day. If the house is empty during the week, say so when you schedule, because that changes which day gets offered.
How a visit works and who does it: About Nero's.
HVAC Replacement Comes With Permits and Inspections
Yes. Prince George's County requires a mechanical permit to replace heating, ventilating or air-conditioning equipment, including a like-for-like swap. The permit is pulled before the work, not after.
The county sets the fee as a percentage of the job, so it scales with the work. It should appear on your estimate as its own line. If a quote has no permit line at all, ask why before you compare it against one that does. Checked 1 October 2026.
The contractor. In Maryland only a Master HVACR licensee can pull an HVAC permit, which means the company doing the work has to hold that license in its own right.
This is the part of Maryland's licensing that most homeowners never see, and it is the reason a cheap quote from somebody working off a general handyman registration cannot legally end in a permitted installation. If a contractor asks you to pull the permit as a homeowner, that is a sign the license behind the quote will not carry it. Checked 1 October 2026.
Clearances around the equipment, how it is vented, how the gas or electrical connection was made, condensate disposal, and whether what was installed matches what the permit said.
The inspection is a pass or fail on workmanship, not on brand or efficiency. Failures in this county cluster around venting and combustion air, especially where a new high-efficiency furnace has been put into a space built for an old one. A good installer plans for the inspection at the quote stage, which is partly why two quotes differ.
Nothing, until you sell. Then it surfaces, because the buyer's side asks for permit history and an unpermitted system can hold up settlement or come off the price.
It also complicates the next replacement, since the county is now looking at work it never inspected. The route through is usually a permit on the new installation that brings the venting and connections up to current code, which is work the previous installer skipped. Tell us up front if you know the last one was done informally. It changes the quote, and we would rather price it honestly than find it on install day.
Yes. DC issues mechanical permits through the Department of Buildings, and a like-for-like residential replacement can often go over the counter without full plan review, which is faster than the Maryland route.
The registration behind it is separate too. DC runs its own contractor register, and a Maryland credential does not carry across the line by itself. That is worth knowing before you assume a company working in both places is on both registers. Ask which one covers your address.
Where we work: Areas we serve.
A Maryland HVAC Contractor's Credentials Are Easy to Check
The HVACR contractor license, issued by the Maryland Department of Labor. It is the one that governs the equipment and the permit, and it comes in grades. Master is the grade that can pull permits. Ours is HVAC R 47671.
Maryland keeps more than one contractor register, so a company can appear on one and not another. Ask for the HVACR number specifically rather than the word "licensed", which is used to mean several different things in this trade. A number can be checked in a minute. A word cannot.
On the Maryland Department of Labor's public license query. Search by company name or license number and you get status, grade and expiry. It takes about a minute and costs nothing.
Look for an active status and a current expiry date. Expired, suspended or revoked all mean the same thing in practice. The Board of HVACR holds disciplinary history separately, and will tell you on 410-230-6309. Do this before any deposit changes hands, not after. Checked 1 October 2026.
Not always, but you should know which it is before you sign. In a lot of companies the person who prices the work is a salesperson on commission and will not be there on install day.
It matters because the quote is a set of decisions about your house, and those decisions get handed over. Ask who is installing, whether they are employed or subcontracted, and who you call if something is wrong in week two. A company that cannot answer that quickly has more hand-offs in it than you were told about.
Not by itself. A small company that has never been reported looks identical on the register to one that has never been found. The register tells you what happened, not what did not.
Read it alongside review volume and how the company answers its bad reviews. A business with two hundred reviews and three complaints that were resolved is telling you more than one with no record of either. What should concern you is an active unresolved complaint, or a license that lapsed and was renewed under a different company name.
Your HVAC Quote Should Show What You Are Paying For
The permit, the electrical disconnect, the line set or its flush, a drain pan and safety switch, haul-away of the old unit, and the sheet metal to make a new cabinet meet old ductwork. Those are the usual six.
None of them are optional. They get left off to make a number look competitive, then arrive as change orders once the old unit is out and the house has no cooling. Compare the line items rather than the totals.
Yes, on equipment. A deposit covers ordering the system and is standard practice across the trade. What is not normal is a deposit on a repair, or a demand for the full amount before anything is delivered.
Anchor it to something physical. A deposit matching the equipment cost, followed by a delivery you can see, is reasonable. Most of the job value in cash before a date is set is not. The same goes for a discount that only exists while somebody is standing in your kitchen. Get the deposit, the balance and the schedule on one piece of paper.
Yes. The federal Energy Efficient Home Improvement Credit, 25C, and the Residential Clean Energy Credit, 25D, were terminated for anything placed in service after 31 December 2025.
A system installed during 2025 can still be claimed on that year's return. Anything from January 2026 onward gets nothing federal. Utility money is separate and has not gone the same way, so do not let an old article set your budget. Ask what is live the month you buy. Checked 1 October 2026.
When the equipment is not what is wrong. A house that cannot hold temperature through a July afternoon on a correctly sized, correctly charged system has an insulation, duct leakage or shading problem, and a bigger unit fixes none of them.
Electrical work and air sealing both fall outside what we do. Sometimes the useful answer is that this is not our job.
What cooling work costs: AC installation and replacement.
Not Every AC Problem Means You Need a New System
Usually not. One system serving two floors delivers most of its air to the path of least resistance, which is the shortest run on the lowest floor. The upstairs is starved rather than the unit being weak.
Heat gain makes it worse upstairs, because that floor sits under the roof and holds the afternoon. The fixes are about distribution: balancing dampers, returns on the upper floor, sealing the runs through unconditioned space, or a separate system for the top floor. A bigger condenser into the same ductwork changes nothing, and it is the most commonly sold answer to this complaint.
No. A sealed system does not consume refrigerant. If it is low, it leaked, and adding more without finding the leak means you will be back where you started, on a schedule set by the size of the hole.
The test is what you are shown. Ask where the leak is and how it was found, and ask to see the readings before anything is added. A technician who has located it can point at it. One who cannot has sold you a season. There are times a controlled top-up is the right call, for example to get through a heatwave before a planned replacement, and that should be said out loud rather than billed as a repair.
It depends on which symptom you have. Ice on the lines, a breaker that keeps tripping, or a unit running with no indoor airflow all get worse with runtime, and those should be turned off and left off.
Weak cooling on a system that is otherwise behaving normally is different, and running it is not making anything worse. What it is doing is costing you, because a system fighting a restriction runs far longer for the same result. If you are unsure which of the two you have, turn it off and describe what you saw when you call.
Sometimes, and it depends on whether the original ductwork has any capacity left. Most additions in this area were added without resizing the trunk, so the new rooms were tapped into a system that was already fully committed.
The honest check is simple. If the rest of the house got worse when the addition was finished, the system is being asked to do more than it can, and extending the ducts further will spread the shortfall rather than fix it. A separate ductless head for the addition often costs less than the sheet metal work, and it leaves the original house alone.
Cooling that has stopped or never kept up: AC repair.
Older Heating Systems Need Different Repair and Replacement Answers
Three, and they do not compete on price alone. Ductless heads, a high-velocity ducted system using small flexible runs, or conventional ductwork where the house has the space to carry it.
Radiator houses have no air distribution at all, so the cooling question is really a distribution question. Ductless keeps the boiler and adds cooling room by room, which suits a house where only the bedrooms matter. High-velocity threads two-inch runs through existing cavities and gets you vents in every room, at a higher installed cost. Conventional ductwork is the most disruptive and is rarely the right answer in a finished older house.
Often, yes. Cast-iron boilers outlast almost everything else in a house, and a thirty-year-old unit that fires cleanly and holds pressure is not a problem waiting to happen just because of its age.
What decides it is combustion and condition, not the date on the plate. A boiler that has lost its expansion tank, weeps at the relief valve or short cycles on every call has something specific wrong, and those are repairs. A cracked section or a flue that cannot be made safe is where the conversation changes. Age on its own is a selling argument, not a diagnosis.
Look for the fuel line and the tank. Gas comes in through a black steel pipe with a meter outside. Oil means a tank, usually in the basement or buried in the yard, and a filter near the burner.
Electric heat has neither, no flue, and a much larger breaker at the panel. Heat pumps are their own category, with an outdoor unit that runs in winter as well as summer. Knowing which one you have changes who you should call and what a service visit covers.
Air movement and surface temperature, not the number on the thermostat. A room at 70 degrees with cold window glass and a draft across the floor reads as cold, because your body is losing heat to the surfaces around it.
This is why one room never keeps up while the rest of the house is fine. The usual causes are a starved supply run, a return that was blocked by furniture, or a radiator with air trapped at the top. It is worth checking before anyone talks about a bigger heating system, since a bigger system heats the same cold surfaces.
Heating that has stopped or never kept up: Heating services.
Older Cheverly Homes Can Change Your HVAC Options
Not what you can install, but it changes what fits and what the work costs. The historic district covers 432 acres built out between 1839 and 1960, so the housing runs from early Cape Cods through post-war ranches and split-levels.
Cheverly also holds 29 Sears and Mitchell & McClure kit houses, the largest known collection in Prince George's County. Kit houses have small, non-standard wall cavities and framing that was cut to a catalog plan, which matters when somebody wants to run a duct through a wall that has nowhere for it to go. Measure before you design. Checked 1 October 2026.
It can, where the unit would be visible from the street. Cheverly and Hyattsville both have historic districts, Hyattsville's running to roughly 600 structures, and exterior changes in view of the public way are the ones that attract review.
An outdoor unit at the side or rear of the house is rarely an issue. One on a front elevation, or a line set run up a street-facing wall, can be. This is worth raising at the quote stage rather than on installation day, because moving the unit changes the line set length and the electrical run. Montgomery County adds its own setback and noise rules on top. Checked 1 October 2026.
Yes, but "central" is doing a lot of work in that sentence. You can have cooling in every room without a conventional duct system, and in a pre-1950 house that is usually the better answer.
Ductless handles it head by head, with one outdoor unit feeding several indoor units, and no ductwork at all. High-velocity ducted systems get you closer to what people picture, using small runs that fit where standard sheet metal will not. Full conventional ductwork in a finished older house means soffits, lost closet space and plaster repair, and it is the option most people drop once they see where the runs would go.
Usually yes, by zoning the existing system rather than replacing it. Dampers go into the trunk runs, each floor gets its own thermostat, and a controller decides which zone the air goes to.
It works where the ductwork has the capacity to be split and the system can modulate or bypass without short cycling. It does not work where the whole house is on one undersized trunk, which is the case in plenty of older homes here. The check is whether the floors can each be satisfied on their own, and that is measurable before anything is bought.
Older homes, awkward layouts and additions: Ductless mini-split installation.
HVAC Warranties and Follow-Ups After the Job
Four things. The signed estimate, the invoice showing what was done, the permit and its inspection result, and the manufacturer warranty registration for the equipment.
The registration is the one that gets lost. Most manufacturers hold the parts warranty at five years unless the system is registered inside 60 to 90 days, at which point it goes to ten. Ask who is doing it and get the confirmation in writing. The permit close-out matters later, at resale, which is the other document people only miss years after the fact.
One year on installations and 30 days on repairs, from us. The manufacturer's parts warranty on new equipment runs separately and much longer.
What shortens it is the thing most people do not read. Manufacturers require documented annual maintenance to honor parts claims, and the claim gets refused when there is no record of it. Changes made by somebody else to the system we installed also fall outside our labor coverage. Neither is unusual in this trade, and both are worth knowing on day one rather than in year two.
It is a call back about six months after a completed job, to find out whether the thing we fixed stayed fixed. There is nothing to buy on it.
Six months is a useful interval because it puts the system through the other season. A sizing or airflow mistake on a summer installation does not show up in August; it shows up in January when the same ducts are asked to do the opposite job. If something is off, we would rather hear it then than read it in a review two years later.
Call us first and say what is wrong, because most of it is fixable and we would rather fix it than argue about it. Put it in writing as well, so there is a record of the date.
If that does not resolve it, Maryland's Board of HVACR takes complaints against licensed contractors on 410-230-6309, and the Maryland Home Improvement Commission handles residential contract disputes separately. Both are public and both are open to you regardless of what any contractor tells you. Knowing the route is part of hiring anyone. Checked 1 October 2026.
Service agreements and what they cover: Maintenance plans.
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