Boiler Inspection Requirements in DC, Virginia & Maryland

You take over a mid-size apartment building in October. In the boiler room, behind a pipe rack, hangs a certificate of inspection for the heating boiler. It expired fourteen months ago. The previous manager assumed the insurance company handled it. The building changed insurers last year, and nobody told the new carrier’s inspector that the boiler existed.

Nothing has failed. But under the boiler inspection requirements in DC, Virginia and Maryland, running a regulated boiler without a valid certificate is a violation in itself, whether or not the boiler is safe. It is also the kind of gap that surfaces at the worst time: after an incident, in an insurance audit, or in a buyer’s due diligence.

This guide sets out those requirements for commercial and multifamily buildings as of October 2026: what is covered, how often each type is inspected, who may inspect, what the certificate means, who may repair a boiler, and what happens when something goes wrong. It ends with a side-by-side comparison, a calendar and a pre-inspection checklist. Tracking these certificates is part of Levaru’s compliance inspections program. This is general information, not legal or engineering advice; the regulator’s current text controls.

What equipment is covered, and what is exempt?

All three jurisdictions regulate boilers and unfired pressure vessels, and Virginia and Maryland use nearly identical definitions. The category decides the inspection interval:

• Power boiler: makes steam or other vapor at more than 15 psi.
• High-pressure, high-temperature water boiler: a water boiler above 160 psi or 250°F. Treated like a power boiler.
• Heating boiler: steam at or below 15 psi, or hot water at or below 160 psi and 250°F. This class covers low-pressure space-heating boilers.
• Hot water supply boiler: heats water for use outside the boiler, such as domestic hot water.
• Unfired pressure vessel: pressurized from an outside source or by indirect heat, such as compressor air receivers and some storage tanks.

Covered equipment must be built to the ASME code, registered, inspected on a fixed cycle and run under a current certificate. Exemptions are narrow, and they cause most wrong assumptions:

Exemption	DC	Virginia	Maryland
Small residential	No equivalent found; ask DOB	Residences and apartment houses under 4 units	Heating boilers in residences and apartment houses under 6 units
Water heaters and hot water supply boilers	Ask DOB	Exempt within 200,000 Btu/hr, 210°F and 120 gallons	Hot water supply boilers exempt within the same limits (direct-fired, with relief valve)
Low-pressure vessels	Annual inspection applies above 60 psi and 15 gallons	Vessels at 15 psi or less	Vessels at 15 psi or less

Exceeding any one of those three limits brings the unit into the program in Virginia and Maryland, and a commercial unit can exceed 200,000 Btu/hr input while holding well under 120 gallons. Small air receivers and water tanks have their own limits; check Virginia’s Boiler and Pressure Vessel Safety Act (§ 40.1-51.8) or Maryland Public Safety Article § 12-903 before you treat a tank as exempt.

How often must boilers be inspected in DC, Virginia and Maryland?

DC inspects every covered boiler and pressure vessel every year. Virginia and Maryland inspect power boilers every year, and heating boilers and most pressure vessels every two years.

Equipment	DC	Virginia	Maryland
Power boiler	Annual	Annual internal, plus annual external where possible	Annual, plus external under pressure if possible
High-temp water boiler	Annual	Same as power boiler	Same as power boiler
Low-pressure steam boiler	Annual	Every 2 years; internal where construction permits	Every 2 years; internal if construction allows
Hot water heating boiler	Annual	Every 2 years; external, internal at inspector’s discretion	Every 2 years; external unless inspector requires internal
Hot water supply boiler	Annual; confirm scope	Confirm interval with inspector	Every 2 years
Pressure vessel	Annual if over 60 psi and 15 gallons	Every 2 years	Every 2 years

An internal inspection examines the boiler shut down, with manhole and handhole plates removed. An external inspection happens while it runs and checks safety devices, gauges and controls under real conditions. The certificate inspection is the one the regulator uses to decide on the certificate; Virginia and Maryland both say it should be internal when construction allows. Under Maryland Public Safety Article § 12-909, the Board of Boiler Rules can extend a power boiler to two years where continuous water treatment runs under a professional engineer’s supervision and the owner keeps the required water analysis records.

DC vs Virginia vs Maryland: how do the programs compare?

The structure is the same everywhere: a commissioned inspector inspects, the regulator issues a certificate, and the owner posts it and keeps it current. The details differ.

Item	DC	Virginia	Maryland
Regulator	Department of Buildings (DOB)	DOLI Boiler and Pressure Vessel Safety	Dept. of Labor, Boiler and Pressure Vessel Safety
Core law	D.C. Code § 2-101 et seq.; 12-E DCMR Ch. 10	Va. Code § 40.1-51.5 et seq.; 16VAC25-50	Public Safety Art. § 12-901 et seq.; COMAR 09.12.01
Who inspects	DOB or DC-licensed insurance company inspectors	Insurance company or contract fee inspectors	Dual-commissioned inspectors at an AIA
Posting	Framed, in boiler or engine room	Room with the object	Under glass, room with the object
Expired certificate	Notify DOB in writing	2-month grace; extension up to 3 months	Invalid on expiration date
New installation	DOB permit, then final inspection	Data report to Chief Inspector before operation	Installer gives 30 days’ written notice
Accident report	Call 911; confirm DOB procedure	Chief Inspector, immediately	Within 24 hours, email and phone
Operator license	DC-licensed engineer of the right class	No statewide license	Stationary engineer for larger high-pressure plants
Penalty for running without a certificate	Fine up to $100 or 90 days per violation	Civil penalty up to $100 per day	Civil penalty up to $5,000 per violation

Who is allowed to perform a boiler certificate inspection?

A commissioned boiler inspector, not your boiler contractor. In Virginia and Maryland, routine inspections are done by inspectors from boiler insurers or private inspection agencies; DC also uses its own DOB inspectors. The regulator issues the certificate from the inspector’s report.

• Virginia. DOLI says it does not conduct routine inspections. Owners use their insurance carrier’s inspector or a contract fee inspector holding a Virginia certificate of competency; DOLI publishes a list of authorized companies. For an uninsured object, a state inspector steps in only when at least two contract fee inspectors will not inspect within 21 days and the certificate expires in that window.
• Maryland. Inspectors must be commissioned by the National Board and by Maryland, and employed by an Authorized Inspection Agency (AIA). If the boiler is insured, the insurer inspects; if not, the owner contracts with an AIA.
• DC. DOB inspectors, or inspectors of boiler insurance companies licensed in DC who hold a DC certificate of competency based on a National Board certificate.

The National Board of Boiler and Pressure Vessel Inspectors issues the commissions behind most of these credentials.

One trap applies everywhere: a certificate issued on an insurance inspector’s report is valid only while the object stays insured by an authorized insurer. Let boiler coverage lapse or drop it, and the certificate can become invalid. When you change carriers, give the new carrier a full list of boilers and vessels, because its inspector now owns the next inspection. DOLI also states that keeping the certificate current is the owner’s job, not the insurer’s.

What is a certificate of inspection, and where must it be posted?

The certificate is the legal permission to operate that specific object. It states the maximum pressure allowed, and running above it is a violation in all three jurisdictions.

• Virginia: post it in the room with the boiler or vessel. The certificate fee is $20 per object. DOLI mails a courtesy reminder about 30 days before expiry but is not required to.
• Maryland: post it under glass in the room with the object. It shows the inspection date, the interval and the maximum pressure.
• DC: one certificate per unit, framed under a durable transparent cover supplied by the owner, displayed in the boiler or engine room near the equipment.

The inspector’s visit and the certificate are different facts. If the report was never filed or the invoice never paid, no certificate issues.

What are the Virginia boiler inspection requirements beyond the schedule?

Virginia’s rules come from the DOLI Boiler and Pressure Vessel Safety program, the Act and the Boiler and Pressure Vessel Regulations (16VAC25-50). Points owners miss:

• Unannounced external inspections. Certificate inspections are scheduled by agreement, but an inspector may make an external inspection during normal working hours without notice.
• Late certificates escalate. Owners get a two-month grace period, and DOLI can extend up to three more months at $20 per month after a satisfactory external inspection. Ninety-one days after expiry, the Commissioner may assign an inspector and bill the owner. Operating without a valid certificate carries a civil penalty of up to $100, and each day is a separate offense.
• State inspection rates. When a Commonwealth inspector must step in, the regulation sets $135 per power boiler, $70 per heating boiler and $50 per pressure vessel, plus the certificate fee.
• New equipment. The manufacturer’s data report goes to the Chief Inspector before operation, and DOLI says new gas-fired water heaters and boilers need an I-1 installation report (NB-365) from the installer.
• No operator license. There is no statewide boiler operator license. Localities may require one; DOLI says none currently does.

What are the Maryland boiler inspection requirements beyond the schedule?

Maryland’s Boiler and Pressure Vessel Safety unit enforces Public Safety Article Title 12, Subtitle 9, and COMAR 09.12.01. It is the most document-heavy of the three.

• Notice before internal inspections. The inspector must notify the owner at least 7 days ahead, and the owner prepares the boiler.
• Records for life. Owners keep legible copies of inspection, maintenance, repair and alteration records at a readily accessible central location in the building, for the life of the boiler, and show them to the inspector.
• 30-day installation notice. The installer files written notice with the Chief Boiler Inspector at least 30 days before installing or reinstalling a boiler or vessel, unless an emergency waiver applies.
• Reports within 30 days. The AIA files each certificate inspection report within 30 days.
• Graded penalties. Under COMAR 09.12.01.36, recordkeeping, posting and late-inspection violations carry up to $1,000 each; violations creating a substantial probability of death, serious injury or serious property damage up to $2,500; operating without a certificate up to $5,000. Willful and persistent operation without a certificate is also a misdemeanor under Public Safety Article § 12-917.
• Licensed operators. Maryland licenses stationary engineers for boilers above 15 psi at 30 horsepower or more, and for high-temperature hot water boilers. Confirm the grade with the State Board of Stationary Engineers.

How does DC boiler inspection work?

DC runs the strictest schedule: annual inspection of every covered boiler and pressure vessel by DOB or a DC-licensed boiler insurance company, under the Boiler Inspection Act (D.C. Code § 2-107) and the DC Mechanical Code (12-E DCMR, Chapter 10).

• Scope. The Act requires certificates for steam boilers above 15 psi (and lower-pressure steam boilers without an unassisted gravity return) and for unfired pressure vessels above 60 psi and 15 gallons. The Mechanical Code calls for annual inspection of all steam boilers, including hot water boilers.
• Timing. Where practicable, the internal inspection happens no later than 15 days before the certificate expires, and never more than 30 days after. Insurance inspectors file reports within 10 business days.
• A licensed engineer and a daily log. The owner must employ or contract an engineer holding the right class of DC license, display it in the boiler or engine room, and keep a daily log of safety and control tests for each tour of duty. Title 17 DCMR, Chapter 4 sets the license classes and exemptions.
• Permits. Adding, replacing or repairing a boiler or pressure vessel needs a DOB boiler permit, and a new or reinstalled unit may not run until it passes final inspection. Each unit gets a DC number.
• No certificate, tell DOB. If a covered boiler has no current certificate, the owner must notify DOB in writing.

Violations can bring a fine of up to $100 or up to 90 days’ imprisonment per violation, or civil infraction penalties.

Who may repair or alter a boiler, and what needs approval first?

Pressure-boundary repairs are regulated work. The inspector must be involved before work starts, and the work follows the National Board Inspection Code (NBIC).

• Virginia: the owner contacts an endorsed special inspector before any repair. Repairs are made by holders of a National Board “R” Certificate of Authorization, and alterations by an ASME or “R” holder. The authorizing inspector accepts the finished work.
• Maryland: the repairer needs inspector approval before any repair that affects working pressure or safety or involves fusion welding, and sends a written report to the Chief Boiler Inspector and the owner within 30 days of completion.
• DC: no welding until DOB or the insurance inspector has inspected the boiler and approved the method, and welders need a DC qualification card.

Safety valves, gauges and controls are covered too. Virginia requires replacements to meet the ASME code or NBIC, and bars work on safety appliances while the boiler runs. Use qualified, appropriately licensed boiler contractors, and keep their repair reports. The next inspector will ask for them.

What happens when an inspector finds a problem?

Most findings are routine: a valve due for replacement, a leaking gauge glass, a missing tag. The owner corrects them and the certificate issues. Serious findings stop the boiler.

• Virginia: if the owner does not agree to correct an unsafe condition promptly, the inspector notifies the Chief Inspector, the certificate is suspended and the boiler may not run.
• Maryland: the Chief Boiler Inspector can prohibit use and attach a notice to the boiler. Running it anyway can cost up to $1,000 per day.
• DC: DOB can order an unsafe boiler out of service and label it “Unsafe to Use.” When an insurance inspector orders repairs, they re-inspect and file a supplemental report within 30 days.

If an accident happens, call 911 first. Virginia requires immediate notice to the Chief Inspector, by phone or another immediate means for a serious accident. Maryland requires notice within 24 hours by email and telephone; its boiler accident line is 410-767-2333. Both states say not to disturb the boiler before the inspector arrives, except to save life (Virginia also allows steps to limit further damage). In DC, notify DOB and your insurer, and confirm DOB’s current procedure.

How is the legal inspection different from maintenance and combustion tuning?

The certificate inspection checks the pressure boundary and safety devices on a fixed cycle. It does not replace maintenance, and it does not tune the burner.

Item	Certificate inspection	Preventive maintenance	Combustion tuning
Purpose	Permission to operate	Reliability	Efficiency and emissions
Who	Commissioned inspector	Staff or boiler contractor	Burner technician
Frequency	1 or 2 years	Daily to annual tasks	Per service plan or rule
Output	Report and certificate	Logs and work orders	Before and after readings

Maintenance is still a legal duty. Maryland makes the owner responsible for proper operation and repair, DC requires daily safety tests in the log, and Virginia points owners to the ASME care rules as the operating guide. Our HVAC preventive maintenance checklist lists the boiler tasks, and our HVAC maintenance program schedules them.

Combustion work can carry its own rules. Some oil-fired boilers fall under EPA’s area-source boiler rule (40 CFR Part 63, Subpart JJJJJJ), which requires periodic tune-ups; EPA’s guidance confirms gas-fired boilers are not covered. That obligation is separate from the safety certificate.

How should you prepare for a boiler inspection?

In Virginia and Maryland, an inspector can decline to inspect a boiler that was not properly prepared, and the certificate is withheld. In DC, the code official can order the boiler out of service until the internal inspection is done. Work through this list two to four weeks ahead and confirm details with your inspector.

Paperwork

1. Current certificate posted for each object; last report with every finding closed.
2. Proof of boiler insurance, if the insurer’s inspector certifies the unit.
3. Repair reports, operating logs, low-water cutoff tests and water treatment records.
4. DC only: the engineer’s license displayed and the daily log current.

External items

1. Nameplate and stamping visible, not buried under insulation or paint.
2. Safety and relief valves with the correct set pressure and capacity, tagged, not leaking, discharging to a safe location.
3. Low-water cutoffs and feeders working. Virginia requires two low-water fuel cutoffs on automatically fired, unattended steam boilers other than miniature boilers.
4. Operating and high-limit controls tested, including the manual-reset limit on steam boilers.
5. Gauges, thermometer and gauge glass readable and working.
6. Burner and flame safeguard checked against ASME CSD-1 or NFPA 85, as applicable.
7. Combustion air openings clear and flue connections sound.
8. Boiler room free of storage, with exits open.

If an internal inspection is due

1. Schedule the outage and warn tenants.
2. Cool, drain and wash out the boiler; open manholes, handholes and plugs.
3. Close, lock and tag shared-header valves and open the drains between them.
4. Remove the pressure gauge for testing, and follow confined-space rules.

What does an annual boiler compliance calendar look like?

Build the calendar around each certificate’s expiry date, because each object can expire in a different month. Then layer seasonal maintenance on top.

Timing	Task
120 days before expiry	Confirm inspector, insurer and policy; pull last report
90 days before	Book the date; book the contractor if internal is due
60 days before	Close open findings; test safeties
30 days before	Confirm the date; notify tenants of outages
Inspection week	Prepare the plant; escort the inspector
0 to 30 days after	Correct findings; confirm report filed; pay invoice
Certificate arrives	Post it; update the record; set next reminder

Plan internal inspections of heating boilers outside the heating season where the expiry date allows, and finish fall start-up and combustion analysis before the first cold snap (our winter building preparation checklist covers that). Boilers share a master schedule with fire, elevator and backflow obligations, set out in our building compliance calendar and our fire and life safety inspection guide.

In buildings Levaru manages, each boiler and pressure vessel gets a QR asset tag and a record in the CMMS included with our service, so the certificate date, last report and open findings sit together in the client portal. The commissioned inspector inspects and qualified contractors repair. We schedule them, prepare the plant, escort the visit and close each finding with a photo-documented work order. The same approach runs under our multifamily property management service.

Frequently asked questions

How often do boilers need to be inspected in Virginia?

Power boilers and high-temperature water boilers need a certificate inspection every year, plus an external inspection while running where possible. Low-pressure heating boilers and most pressure vessels need one every two years. DOLI does not perform these routinely; your insurance carrier’s inspector or a contract fee inspector does, and DOLI issues the certificate from the report.

Who do I call to get a boiler inspected in Maryland?

If the boiler is insured, the insurer’s inspector does the certificate inspection. If not, contract with an Authorized Inspection Agency whose inspectors hold both a National Board and a Maryland commission. The Maryland Department of Labor lists authorized agencies on its Boiler and Pressure Vessel Safety pages. The agency files the report, and the Chief Boiler Inspector issues the certificate.

Do apartment buildings need boiler inspections?

Usually. Virginia exempts only private residences and apartment houses with fewer than four apartments. Maryland exempts heating boilers in residences and apartment houses with fewer than six family units. Larger buildings are inside both programs. We found no comparable small-building exemption in DC’s rules, so confirm with the Department of Buildings before treating a DC apartment boiler as exempt.

Are commercial water heaters subject to boiler inspection?

They can be. In Virginia and Maryland, water heaters and hot water supply boilers are exempt only within all three limits: 200,000 Btu per hour input, 210°F and 120 gallons. Exceeding any one brings the unit into the program, and a compact commercial unit can exceed the input limit. In DC, confirm the treatment of large water heaters with the Department of Buildings.

What happens if a boiler certificate expires?

Virginia allows a two-month grace period and up to three more months by paid extension, after which operating risks a civil penalty of up to $100 per day. In Maryland the certificate is invalid on its expiration date, and operating without one risks a penalty of up to $5,000. In DC, the owner must notify the Department of Buildings in writing.

Does my insurance company’s inspection count as the state inspection?

Yes. In all three jurisdictions, an inspection by the insurer’s qualified inspector can support the certificate. The catch is that the certificate depends on the insurance: if boiler coverage lapses, the certificate can become invalid. When you change carriers, give the new carrier a full list of your boilers and vessels so nothing misses its next inspection.

Is a boiler inspection the same as annual boiler service?

No. The certificate inspection is a jurisdictional safety check by a commissioned inspector on a one- or two-year cycle. Annual service is maintenance by your staff or boiler contractor: cleaning, burner adjustment, combustion analysis and control tests. You need both, and good maintenance records make the inspection faster because inspectors ask for them.