Does Delaware Require CO Detectors? Rental and Lodging Rules

Last verified: August 26, 2026

Delaware puts its carbon monoxide detector law in a lodging chapter, Title 16, Chapter 66C. Coverage follows establishment type, which leaves owner-occupied private homes outside the statute. The statute reaches many rental and hospitality properties, including apartments, hotels, and similar paid sleeping units when risk factors such as fuel-burning equipment or attached-garage exposure are present.

Chapter 66C also sets owner and tenant duties, installation standards, and enforcement pathways through the State Fire Marshal and Justice of the Peace Court process. Because compliance includes ongoing maintenance and documentation duties, operators should treat it as a recurring property control, not a one-time installation event.

Operators should retain placement records, testing logs, tenant notices, and corrective-action timelines for each covered unit.

Quick Safety Summary

CO detector requirements for Delaware
Applies to homes?	No
Applies to rentals?	Yes
Applies to hotels/STRs?	Yes
Applies to schools?	Yes, under a condition
Applies to workplaces?	Yes, under a condition

Schools and workplaces

Schools: it depends, and the test is one you can apply to the building itself. Two instruments reach a Delaware school and they answer different halves. Chapter 66C of Title 16 is not the route: Section 6601C excludes "dormitories and other living or sleeping facilities owned or maintained by public or private schools, colleges, universities, or churches unless made available to the general public and not used exclusively for students and faculty", so a campus dormitory sits outside the chapter for as long as it houses students and staff alone, and inside it the summer it starts letting rooms to the public. The route that does reach a classroom is the fire code, and it is statewide even though the building code is not. 1 Del. Admin. Code 701 adopts NFPA 101, Life Safety Code, 2021, and NFPA 101 is organised by occupancy rather than by an occupancy-group list. Section 14.3.4.4 covers a new educational occupancy and Section 15.3.4.4 an existing one, and both ask the same four questions: a detector on the ceiling of any room containing a permanently installed fuel-burning appliance, one centrally located within occupiable spaces served by the first supply air register from a permanently installed fuel-burning HVAC system, one centrally located within occupiable spaces adjacent to a communicating attached garage, and one where that garage is separated by gypsum panels. Where a detector goes in on the first of those, 15.3.4.4.2 requires the alarm signal to be transmitted automatically to an approved location. Two consequences follow for a Delaware district. The duty asks nothing about construction date or permit history, so an old school owes the same as a new one. And Delaware's own modifications to NFPA 101 do not touch chapters 14 or 15 or any carbon monoxide provision, so the base text governs. Building codes remain county and municipal. Four jurisdictions were read on 2026-08-11 - Wilmington, Newark, Dover and New Castle County - and none carries a school provision of its own, so what a local code adds sits on top of the fire code rather than in place of it.

Workplaces: it depends, and the test is one you can apply to the building itself. Assembly is the one workplace Delaware's route reaches. Chapter 66C of Title 16 reaches lodging establishments as Section 6601C defines them, a list of dwellings and places let to guests, and an office, shop or factory is not among them. Delaware has no statewide building code that could carry a second route, its construction codes being adopted county by county and town by town. What is statewide is the fire code. 1 Del. Admin. Code 701 adopts NFPA 101, Life Safety Code, 2021, whose Section 12.3.4.4.1 requires carbon monoxide detection and warning equipment in a new assembly occupancy on the ceilings of rooms containing permanently installed fuel-burning appliances or fireplaces, centrally within occupiable spaces served by the first supply air register from a permanently installed fuel-burning HVAC system, and centrally within occupiable spaces adjacent to an attached garage, with garages and open or mechanically ventilated parking excepted at 12.3.4.4.2. So a new restaurant, bar, theatre or place of worship with a fuel-burning appliance is inside it. The limit is the edition rather than the occupancy. NFPA 101 gained an existing-assembly provision at 13.3.4.4 in its 2024 edition, and Delaware is on the 2021, so an assembly occupancy already standing is outside this. The business, mercantile, industrial and storage chapters require nothing in either edition, so an office, a shop, a factory and a warehouse are outside whatever the edition. No International Code edition reaches Group A at all. Of the four local jurisdictions read on 2026-08-11 the only carbon monoxide provisions found reach dwelling units and hotel or motel rooms.

When Are CO Alarms Required?

Buildings with fuel-burning appliances
Buildings with attached garages
New construction
Chapter 66C uses a lodging-establishment scope model tied to listed risk conditions.

Where to Install CO Alarms

Install required devices in each covered dwelling or sleeping unit, with detailed in-unit placement set by State Fire Marshal rules.

For detailed placement guidance beyond legal requirements, see where to place carbon monoxide detectors.

Device Requirements

Devices must provide interconnected notification throughout the required area or initiate the building alarm system where applicable.
Primary power from building wiring is required for covered installations.
Battery backup is required when building power is interrupted.

Landlord and Tenant Responsibilities

Landlord: Covered owners and operators must install and maintain required devices and keep them operable. Provision: Sections 6601C through 6605C.

Tenant: In lodging units leased for one month or longer, tenants are responsible for keeping device batteries operable where the statute assigns that duty. Provision: Sections 6601C through 6605C.

Lease language should define battery, testing, and reporting responsibilities for each unit type.

Full Delaware landlord and tenant carbon monoxide duties, with citations

Enforcement

Enforced by: Delaware State Fire Marshal with Justice of the Peace Court jurisdiction for cited violations.

Enforcement typically occurs:

During complaint response, alarm-response follow-up, or compliance inspections in covered lodging occupancies.
When required devices are missing, inoperable, disconnected, or not installed per governing rules.

The Fire Marshal or Attorney General may seek injunctive relief to stop continuing violations.

What a Tenant Can Do in Delaware

When a carbon monoxide alarm stops working in a rented home in Delaware, these are the five routes a tenant can take and where each one comes from.

"Via general law" means the Delaware carbon monoxide statute itself is silent and the remedy comes from the state's landlord-tenant law instead. The remedy is available even though the alarm rule does not contain it.

Tenant remedies for a defective carbon monoxide alarm in Delaware, with the citation or the body of law searched for each.
Rent withholding	Via general law25 Del. C. 5308(a)(2). Delaware is one of two states in the fifty-one that fix the retained fraction in the statute rather than leaving it to be assessed, New Mexico being the other, and Delaware's fraction is the larger: after the failure has continued 48 hours from the tenant's actual or written notice, the tenant may keep two thirds of the per diem rent accruing. How far that reaches a carbon monoxide defect is uncertain, and the uncertainty is worth stating. The trigger in 5308(a) is wide, covering any condition that materially deprives the tenant of a substantial part of the benefit of the bargain in violation of an applicable housing code, but the fraction in paragraph (2) is measured across periods when hot water, heat, water, electricity or substitute housing is not supplied. A dead alarm answers the trigger and does not obviously answer the measure.
Repair and deduct	Via general law25 Del. C. 5307. One of two caps in the fifty-one written the wrong way round, with Illinois. A tenant may deduct a reasonable sum not exceeding $400, or one half of one month's rent, whichever is less, where Arizona, Hawaii, Kentucky, Maine, Missouri, Nevada, Texas and Virginia all say whichever is greater. The direction is what matters rather than the figure: everywhere else the cap is a floor that protects a tenant in cheap housing, and in Delaware it is a ceiling that bites them hardest, because a tenant paying $700 a month is held to $350 while the $400 never applies to them at all. Two clocks run in parallel. The landlord has 30 days from receipt of the written notice to remedy the failure, or 10 days to initiate reasonable corrective measures such as obtaining an estimate, and missing either one opens the remedy. A tenant otherwise delinquent in rent may not use it, and the tenant carries liability for damage caused while making the repairs.
Right to end the lease	Via general law25 Del. C. 5306(a). The strongest termination provision found anywhere in this matrix for a hazard. The ordinary route gives the landlord 15 days from written notice of a condition depriving the tenant of a substantial part of the benefit of the bargain. But where the condition renders the premises uninhabitable or poses an imminent threat to the health, safety or welfare of the tenant or a family member, the tenant may terminate immediately after notice and without going to a Justice of the Peace Court. A tenant who terminates wrongfully stays liable under the agreement, so the judgment call carries risk.
Notice the tenant must give	Via general law25 Del. C. 5306(a); 5307(a). Written notice with no waiting period attached, and Delaware is unusually relaxed about form: 5308 will accept actual notice as well as written. What the tenant has to get right is which section they are invoking, because the same letter buys a 15-day clock under 5306, a 30-day or 10-day clock under 5307, and a 48-hour clock under 5308.
Landlord cure period	Via general law, 15 days25 Del. C. 5306(a). Fifteen days is the general figure and it is recorded here, but it is the longest of the three and the least likely to govern a carbon monoxide problem. 5308 cuts the wait to 48 hours where the failure violates an applicable housing code, and 5306 removes the cure period altogether where the condition renders the unit uninhabitable or poses an imminent threat, which is the route a live hazard takes.

Applies to every row above:Delaware is not a URLTA adoption. Chapter 53 of Title 25 runs on its own architecture from 5301 to 5316, and the test the model act suggests comes back negative here: essential services sits at 5308 and fire and casualty at 5309, adjacent to each other with nothing between them, so the counterclaim section that occupies that slot in Alaska, Iowa, Kansas, Hawaii, Kentucky and Connecticut has no counterpart in Delaware. What Delaware offers instead is three separate self-help routes with three different clocks, which is why no single number describes this row. A caveat on currency, kept because it earned its keep. delcode.delaware.gov refuses automated requests and the newest archived capture returning content is from 21 June 2020, so the sections below were originally quoted from that capture. Every figure below was re-read against a current mirror of the Delaware Code on 2026-08-12 and is stated as that reading found it.

Remedies last checked 2026-08-03. Compare Delaware with the other states.

What Delaware Requires in Lodging

The Delaware carbon monoxide requirement reaches hotels and short-term rentals.

Hotels already standing: covered too. The Delaware requirement reaches an existing hotel and not only one being built.

Operator duty: Covered lodging operators are treated as owners for compliance under Chapter 66C definitions.

Full Delaware hotel and short-term rental requirements

Penalties for Non-Compliance

Delaware law provides civil fine exposure of $100 to $500 per offense for Chapter 66C noncompliance and tampering scenarios.

16 Del. C. Chapter 66C enforcement and penalty provisions including section 6605C.

Additional Notes

Chapter 66C is not a blanket statewide mandate for all owner-occupied private homes.
Placement specifics should be confirmed against current Fire Marshal rules for the exact occupancy type.

Local Rules That Differ From State Law

At least one Delaware municipality sets CO requirements that go beyond the statewide rule. Where your property sits decides which applies, and the stricter one governs.

Wilmington

Wilmington measures in forties where most jurisdictions measure in tens, and it covers the whole housing stock rather than the lodging trade. Section 34-232.1 of the housing code requires at least one approved carbon monoxide alarm in each residential unit, installed within 40 feet of each room used for sleeping purposes and sited so that it is easily audible in all sleeping rooms. Forty feet is the loosest distance figure in this dataset and the audibility clause is what carries the weight, so read the two together rather than treating the distance as the standard. Paragraph (3) adds a separate trigger aimed at the commonest Wilmington hazard: any dwelling unit or hotel or motel room with fossil-fuel space heating equipment inside the unit or room needs at least one alarm regardless of anything else. Paragraph (4) requires UL 2034 or equivalent and lets the commissioner of licenses and inspections issue implementing rules. Paragraph (5) makes it unlawful to remove the batteries or otherwise disable a required alarm, excepting an owner or manager replacing batteries in the normal way. Paragraph (6) splits the duties: the owner installs and supplies carbon monoxide testing and maintenance information to at least one adult tenant in each dwelling unit, and the tenant tests, maintains and replaces the batteries. Section 34-45 is the enforcement half. Rental inspections in Wilmington exist to enforce life safety items, and smoke and carbon monoxide detectors are the first named on the list, ahead of heating, hot water, electrics, sanitation and egress.

Wilmington City Code Section 34-232.1, carbon monoxide alarm devices, with the rental inspection purpose at Section 34-45 Checked 2026-08-11.

Newark

Newark writes its rule into the property maintenance code, which is what reaches a building already standing. Section 17-4(aa) adds a new Section 601.3 to the International Property Maintenance Code as Newark adopts it, requiring a carbon monoxide alarm in the immediate vicinity of all sleeping rooms of each dwelling unit that has fuel-burning appliances or equipment, or an attached garage, or an attached storage or utility room in which fuel-burning equipment is stored. That third trigger is the addition worth noticing: most jurisdictions stop at the appliance and the garage, and a mower or a generator kept in an attached shed brings a Newark dwelling inside the rule. One drafting point to check before quoting the ordinance. Section 601.3.1 requires single station alarms complying with "UL 2304". The standard for single and multiple station carbon monoxide alarms is UL 2034, which is the number Wilmington's own ordinance uses, and UL 2304 is not a carbon monoxide alarm standard. The text reads as a transposition rather than a deliberate choice, but it is what the code says.

Newark, Delaware, Code Section 17-4(aa), adding Sections 601.3 and 601.3.1 to the adopted International Property Maintenance Code Checked 2026-08-11.

What was checked:Delaware runs the opposite way from the uniform-code states and the codes themselves show it. Connecticut, Minnesota and Montana all bar a municipality writing its own construction rules, so every local carbon monoxide finding in those states had to sit in a housing or licensing chapter. In Delaware, New Castle County publishes its own amendments to the International Building Code and Newark publishes its own amendments to the International Property Maintenance Code, both as ordinances. Construction and maintenance codes are adopted locally here, which is why the two entries below are able to sit exactly where a uniform-code state forbids. That matters more than usual because of what the statute leaves out. Title 16 Chapter 66C attaches to lodging establishments and paid sleeping accommodation rather than to housing at large, so an owner-occupied Delaware home is outside it. Both cities below reach dwelling units generally. Four jurisdictions read on 2026-08-11: Wilmington, Newark, Dover and New Castle County. New Castle County is not in the table: its amendment at Section 6.04.002 routes carbon monoxide detection to Section B915 of the code it adopts, which is adoption rather than addition. Dover is not in the table either, and its one hit is worth naming anyway because it is unlike anything else in this dataset: the recreational and commercial zoning district requires tent camping sites to be laid out so that tail pipes, generators and other carbon monoxide sources are not near the tents, and lets the fire marshal order a vehicle or a tent moved to avoid the danger. Sussex County and the beach towns, Rehoboth, Dewey, Bethany and Fenwick Island, were not searched, and between them they hold most of the state's seasonal letting.

Local sweep last reviewed 2026-08-11.

Official Sources & References

Delaware State Fire Prevention Regulations, 1 Del. Admin. Code 701, NFPA codes and standards adopted , 701-7-1.0, the adoption list, and the modifications to NFPA 101 (fire code, accessed 2026-08-26)
An edition-currency check run on 2026-08-26 that turned into a coverage finding, because this instrument had never been brought to the question at all. Delaware adopts "NFPA 101, Life Safety Code, 2021" alongside NFPA 1 in its 2021 edition and NFPA 72 in its 2019, effective 1 July 2021. The distinction that matters is between a building code and a fire code. Delaware genuinely has no statewide building code, and the school and workplace rows here were closed on that fact. But NFPA 101 is adopted statewide, it is organised by occupancy rather than by an occupancy-group list, and it carries carbon monoxide provisions in the educational and assembly chapters that no International Code edition reaches: 14.3.4.4 for a new educational occupancy, 15.3.4.4 for an existing one, and 12.3.4.4 for a new assembly occupancy. Delaware's own modifications were read for deletions and there are none that matter here. The state amends 9.2.2, 16.3.4.4, 24.1.1.1, 26.3.4.4.1, 30.3.4.1.1, 30.3.4.4.1 and parts of chapter 32, and it does not delete or amend chapters 12, 14 or 15 or any carbon monoxide provision, so the base text governs each of them. The edition sets the limit on the assembly answer. An existing assembly occupancy is reached at 13.3.4.4, which is new in the 2024 edition; Delaware is on the 2021, so an assembly building already standing is outside. A May 2025 rulemaking was checked and does not move the edition - it concerns plan review and licensing.
Delaware Code Title 16 Chapter 66C Carbon Monoxide Detection Devices , Sections 6601C through 6605C (state code, accessed 2026-02-17)
Primary statewide statutory text for scope, triggers, duties, and penalties.
Delaware General Assembly Senate Substitute 1 for Senate Bill 91 , Enacted chapter language creating Chapter 66C (state code, accessed 2026-02-17)
Legislative history and enacted statutory framing for Chapter 66C requirements.
Delaware State Fire Marshal carbon monoxide detectors in lodging establishments , Agency overview page (agency guidance, accessed 2026-02-17)
Enforcement-facing guidance that summarizes Chapter 66C obligations.
Delaware Code Title 25 Chapter 53, tenant remedies (Sections 5306, 5307 and 5308) , 25 Del. C. 5306(a), 5307 and 5308(a) (state code, accessed 2026-08-12)
The instrument every tenant-remedy cell on this page rests on, and it had no source entry. Added because the remedy block discloses that its figures came from a 21 June 2020 archive capture, delcode.delaware.gov refusing automated requests, and a six-year-old capture behind a dollar amount is exactly the thing to re-read. Re-read on 2026-08-12 by two independent extraction paths that agree. 5307 lets the tenant deduct a reasonable sum "not exceeding $400, or 1/2 of 1 month's rent, whichever is less", after the landlord fails to remedy within 30 days of receipt of the written notice or to initiate reasonable corrective measures within 10 days. The record carried $200; the figure is $400. The 30-day and 10-day clocks and the inverted "whichever is less" both confirmed as written.

Disclaimer: This page explains the law as it stood on August 26, 2026. It is general information, not legal advice, and reading it creates no attorney-client relationship. Requirements vary by city, county and building type, and statutes and codes are amended: confirm the current text with the issuing authority before acting on it. Each requirement here cites the instrument it comes from, so you can check it at source.

Frequently Asked Questions

Which Delaware law is the main carbon monoxide detector requirement for rentals and hotels?

Title 16, Chapter 66C is Delaware's main statewide CO detector law. It applies to covered lodging establishments, including many apartments and hospitality units, and ties obligations to risk conditions such as fuel-burning equipment or attached-garage pathways. Operators should treat Chapter 66C as the baseline compliance document for installation, maintenance, and documentation duties. The best practice is to cite section-level language in local checklists so inspection, maintenance, and legal teams are using the same compliance standard during audits.

What property types are covered as lodging establishments in Delaware?

Chapter 66C uses a broad lodging-establishment model that can include hotels, motels, bed and breakfast properties, and many paid dwelling or sleeping units. The category runs wider than the word hotel suggests, which is how multifamily rental operators are caught by it, and it is also why owner-occupied private homes sit outside the statute altogether. Delaware wrote its carbon monoxide duty into a lodging chapter rather than a housing one, so coverage follows what the establishment is rather than what the building contains, and that is the reverse of almost every other state. Two Delaware municipalities have gone further than the state did. Both were read in August 2026 and both reach ordinary dwelling units, which Chapter 66C does not.

What installation and power standards apply under Delaware Chapter 66C?

Delaware's cited statutory framework requires devices to be installed in covered units with interconnected signaling outcomes and hardwired primary power plus battery backup. Exact in-unit placement details are handled through State Fire Marshal rules, so operators should align site plans with current agency requirements for the occupancy type. Installation quality records should include device model, power method, interconnection test result, and inspection date. That record set helps reduce disputes during follow-up enforcement reviews.

What penalties can apply for missing or inoperable Delaware CO detectors?

Chapter 66C includes civil penalty exposure in the $100 to $500 range per offense for covered noncompliance and tampering behavior. Enforcement can move through State Fire Marshal action and Justice of the Peace Court pathways when required devices are absent, disabled, or not maintained as required. Property operators should treat each notice as time-sensitive and track correction dates carefully. A complete notice-to-repair timeline often becomes the most important evidence if a case escalates.

Are all-electric Delaware units automatically exempt from detector duties?

Not automatically. Delaware's statewide framework is occupancy and trigger based, and scope can involve factors beyond a simple utility profile, including attached-garage exposure and statutory lodging definitions. Owners should review the specific unit and occupancy against Chapter 66C and applicable Fire Marshal rules before recording an exemption decision. A defensible exemption file should include the trigger analysis, reviewer name, and decision date so future inspections can verify the rationale. Delaware property managers should revisit this analysis after major remodels.

How does Delaware compare with Maryland for Mid-Atlantic compliance planning?

Delaware centers its statewide approach on Title 16 Chapter 66C for covered lodging occupancies, while Maryland operators often work through a different state and local code mix depending on building type. Regional teams should avoid a single shared Mid-Atlantic checklist without state-level branching. For comparison planning, review Maryland CO detector laws and map differences in trigger logic, role allocation, and enforcement workflow before rollout. Delaware compliance teams should document state-specific training steps for each workflow branch.

Practical CO Detector Guides

Beyond legal requirements, these guides help you choose, install, and maintain CO alarms:

Where to place carbon monoxide detectors, room-by-room placement recommendations
CO detector beeping patterns, what different alarms mean
What to do if your detector goes off, emergency response checklist
CO resources and links, official agencies and safety information