Smoke and CO Alarm Replacement Work Orders

A property manager sends a short list before a rental inspection:

Replace nine old smoke and CO detectors. Test everything. Send one invoice.

The first bedroom has a battery-powered smoke alarm. The hallway has a hardwired combination smoke and carbon monoxide alarm interconnected with the other household alarms. The basement device has no readable date. One ceiling device is part of a monitored fire alarm system. A tenant says the upstairs unit chirped last night, but nobody recorded whether it was an alarm, a low-battery chirp, or an end-of-life signal.

This is not a simple nine-device swap.

Before anyone prices the job, the shop needs an inventory, a code-and-product check, an electrical work plan, specific tests, and a customer handoff. A work order that says only “replace detectors” loses the facts that show whether the right devices were installed and whether the job is actually complete.

Start with a work request intake that captures the building type, occupied areas, reported alarm condition, access contact, owner authorization, fuel-fired appliances, attached garage, permit or inspection deadline, and whether any device connects to a control panel or monitoring service. Use an electrical inspection report when the first visit is a paid survey rather than an installation. Carry the approved device schedule into the electrical work order, then close the work with a service report and customer sign-off.

Before a routine dispatch, the shop should be able to answer these questions:

• Is there an active smoke or CO alarm, an end-of-life signal, a low-battery chirp, a trouble condition, or only a planned replacement?
• Is each device a self-contained alarm, a detector connected to a fire alarm system, or an unidentified device that needs inspection?
• Which rooms, stories, sleeping areas, fuel-fired appliances, garages, and accessibility or notification needs affect the device plan?
• What make, model, manufacture date, power source, backup power, listing, and interconnection does each existing device use?
• Which code edition and local amendments does the authority having jurisdiction (AHJ) enforce for this property and scope?
• Does the job require like-for-like replacement, added locations, new wiring, wireless interconnection, system service, a permit, or an inspection?
• Which replacement models are listed for their intended use and compatible with the retained equipment?
• How will hardwired equipment be deenergized, verified, replaced, restored, and tested?
• What counts as a passed device test, an interconnection test, an exception, a declined recommendation, or a return visit?
• What instructions, dates, photos, warranty information, and emergency-response notes will the owner receive?

First, decide whether it is an alarm or a system detector

Customers, stores, and even work orders often call every round ceiling device a “detector.” The distinction matters when the shop accepts the job.

UL Solutions’ smoke and gas device guidance separates the common product categories:

The 2024 International Residential Code draws the same line: household smoke and CO alarms use the UL 217 and UL 2034 paths, while substitute household fire alarm or CO detection systems use the UL 268 or UL 2075 paths and NFPA 72.

That distinction should appear at the top of the scope:

Scope includes the listed single- and multiple-station household alarms identified in Device Schedule A. It does not include fire alarm control equipment, system smoke or CO detectors, notification appliances, initiating circuits, supervisory service, monitoring, sprinkler interfaces, elevator functions, access-control interfaces, programming, acceptance testing, or certification unless that work is expressly included in the approved scope.

If a ceiling device communicates with a control panel, has system wiring or an address, activates building notification, reports to a supervising station, or cannot be positively identified, stop the plug-swap assumption. Record it as an exception and route it to the person licensed and qualified for that system and jurisdiction.

Do not remove or disable an unidentified life-safety device merely to make the device count match the quote.

Build the existing-device schedule before selecting replacements

Walk the property by level and room. Give each existing and proposed device a stable ID such as L1-BED1-SA-01 or B1-HALL-CO-01. A site assessment checklist can carry the building-wide facts; the device schedule carries the unit-level facts.

Record at least:

Take one clear photo of the front of the device and, when it can be done safely, a label photo before disposal. The photo requirements for every work order explain why the label image, location image, and completion image answer different questions. Do not fill a customer folder with nine identical ceiling close-ups that cannot be matched to rooms.

The model and date fields also make the file searchable later. The CPSC recall database identifies affected smoke and CO products by details such as brand, model, date code, markings, or configuration. A passing manual test does not tell you whether the exact model is subject to a recall or safety warning.

A current example shows why exact identification matters. In its July 9, 2026 warning for JNHCD combination devices, CPSC told consumers to stop using and dispose of the affected products immediately. In the June 25, 2026 Treatlife recall, CPSC told consumers to continue using the affected product until a replacement was installed, then follow specific marking, battery, and disposal steps. Products sold under the same broad description can therefore require different interim actions.

Follow the remedy stated for the exact product. Do not turn the word “recalled” into a generic instruction to remove, discard, or leave a life-safety device in service.

Separate the adopted rule from general safety guidance

A national article cannot tell a contractor exactly how many alarms a particular house needs. The controlling rule can depend on the state and local code edition, amendments, property type, age, occupancy, permit scope, rental or sale status, and whether the devices form part of a fire alarm system.

The 2024 IRC is a model code, not proof of local adoption. In that edition, household smoke alarms are in Section R310 and CO alarms are in Section R311. Earlier adopted editions commonly use different section numbers. If an old checklist cites R314 and R315, verify the locally adopted edition instead of changing a number and calling the checklist current.

For new dwellings, the 2024 model provisions include these core decisions:

Consumer safety guidance can be broader or simpler than a code minimum. CPSC guidance recommends smoke alarms on every level, outside sleeping areas, and inside each bedroom, and recommends CO alarms on each level and outside sleeping areas. The U.S. Fire Administration gives similar smoke alarm placement and maintenance guidance and CO prevention guidance.

Write whether a device is included because the adopted code requires it, the AHJ requested it, the manufacturer’s instructions require it, the owner chose a documented upgrade, or the shop recommended it as safety guidance. Those are different bases and should not be blurred into “brought house to code.”

Existing buildings need a replacement rule, not only a location rule

The 2024 International Property Maintenance Code offers a useful model for an existing-device survey, but it is not a nationwide rule; local adoption and amendments still control. Section 704.7.1 calls for smoke alarm replacement when the device fails an operability test, exceeds 10 years from the marked manufacture date unless instructions require earlier replacement, produces an end-of-life signal, or has no determinable manufacture date. Section 705 addresses CO alarm and detector maintenance and replacement when a device is inoperable or produces an end-of-life signal.

That is why “installed about eight years ago” is not a complete age record. Smoke alarm age is commonly measured from the marked manufacture date, not the day the customer remembers moving in. A CO alarm’s replacement point can differ by model, so record the manufacturer’s replace-by or end-of-life instruction rather than assigning every CO device the smoke-alarm ten-year rule.

The 2025 edition of NFPA 72 places inspection, testing, and maintenance in Chapter 14 and household alarms and signaling systems in Chapter 29. Use the edition adopted or required for the project and the manufacturer’s published instructions; do not turn a consumer test-button press into a claimed NFPA system inspection.

Local requirements can add a separate transaction or permit workflow. For example:

• California Health and Safety Code §13113.7 addresses approved and listed smoke alarms, certain permit sign-offs, rental-owner responsibilities, entry notice, and distinctions for fire alarm systems.
• Massachusetts requires a local fire department certificate for covered sales or transfers and publishes a separate smoke and CO alarm inspection preparation guide. Its Department of Fire Services also describes state-specific rules for replacement battery-powered alarms and hush features on its smoke and CO alarm page.

These are examples of why the quote must name the jurisdiction and trigger. They are not national instructions and should not be copied into a job in another state.

If the alarm review is triggered by a service-upgrade or panel-replacement project, list the survey and any corrections as a separate scope instead of hiding them inside “permit included.” The panel-upgrade quoting guide shows how to keep AHJ requirements, utility work, panel work, and added alarm work from becoming one unpriced promise.

Quote the decision, not a guessed device count

If the property has no current device schedule, sell the survey before promising a fixed number. Use the electrical quote estimate to separate the inspection from the installation and to show which unknowns can change the price.

A practical quote can break out:

• intake, occupancy coordination, existing-device survey, photos, label capture, and device schedule;
• code-edition, AHJ, permit, inspection, sale, rental, or program check included in scope;
• each replacement alarm by function, power, interconnection, accessibility feature, and location;
• new outlet boxes, permanent wiring, wireless interconnection, circuit tracing, or relocation expressly included;
• ladder, scaffold, lift, attic, high-ceiling, locked-unit, furniture-moving, or after-hours access;
• monitored-system coordination, impairment notice, or fire-alarm contractor work when specifically included;
• whether ordinary mounting hardware, connector adapters, trim plates, patching, painting, finish repair, and cleanup are included or excluded;
• testing of each device, interconnection group, visible/audible feature, and documented exception;
• permit and inspection fees, failed-inspection correction boundary, and return visits;
• removed-device and battery handling, recall remedy, owner retention, or disposal responsibility; and
• customer instructions, final device schedule, warranty documents, service report, invoice, and sign-off.

Avoid a line such as “replace all smoke detectors with 10-year combo units.” It does not say whether every location should be a combination location, whether the devices are listed for the intended use, whether existing hardwired alarms can interconnect with them, whether accessibility features must be preserved, or whether one device actually belongs to a fire alarm system.

A better scope is:

Replace the twelve household alarms listed in Device Schedule A with the specified models, listed for their intended uses, at the recorded locations. Price includes the mounting or connector adapters permitted by the product instructions, hardwired connections, battery backups, compatible interconnection, device and all-sound tests, label and completion photos, owner instructions, and final schedule. New circuits, concealed wiring repair, added alarm locations, monitored fire alarm work, system detectors, notification appliances, finish repair, permit revisions, and inaccessible units are excluded unless listed or approved by written change.

Compatibility belongs in the submittal, not in the truck aisle

A connector that fits is not proof that an alarm is approved to join the existing network.

For each proposed model, record:

• manufacturer and exact model;
• household alarm function or system-detector function;
• listing marks and applicable product standards;
• approved occupancy and environment;
• power and backup-power requirements;
• mounting location and prohibited locations;
• hardwired or wireless interconnection method;
• compatible retained models, modules, relays, accessories, and maximum group limits from the instructions;
• audible, voice, visual, low-frequency, bed-shaker, or other notification features being preserved;
• end-of-life signal and replacement interval;
• maintenance and test method;
• warranty term and claim route; and
• recall search result and date when the shop includes that check.

UL’s CO alarm guidance explains that a combination smoke/CO alarm is listed in both household categories and that AC-powered CO alarms include standby battery power. It also notes that the manual test switch activates the unit’s alarm indicators and that newer CO alarms use a distinct end-of-life signal.

Do not promise that a smoke/CO combination alarm detects natural gas or propane unless the exact product is separately listed and labeled for that function. UL distinguishes CO alarms from combustible-gas devices. The work order should repeat the product’s real functions, not the marketplace title that sold it.

If the home has a mixture of retained and replacement devices, attach the manufacturer’s compatibility basis. “Same voltage” and “same plug” are not a compatibility schedule. A listed connector adapter addresses the physical connection only when the instructions permit it; the adapter alone does not establish interconnection compatibility.

Treat the test button as one test, not every test

The customer sees the technician press a button and hears noise. The final report says “all tested good.” That statement is too broad.

Name the test and result:

A manual test button checks only the functions the manufacturer says it checks. It does not prove that the device was exposed to a calibrated smoke or CO concentration, that every sensing pathway was field-tested, that an entire fire alarm system passed, or that the installation meets every local requirement.

Do not use vehicle exhaust, an open flame, cigarettes, uncontrolled smoke, or an unapproved aerosol to “prove” an alarm. Use only the test and cleaning methods permitted by the product instructions and the applicable system standard.

CPSC recommends monthly testing for smoke and CO alarms. That homeowner maintenance recommendation does not authorize a contractor to overstate the scope of a completion test.

Control the hardwired work and the temporary impairment

Changing a hardwired household alarm can expose a worker to building wiring and can temporarily reduce life-safety coverage. Plan both conditions.

For employees covered by general-industry rules, OSHA 29 CFR 1910.333 requires safety-related work practices around electrical hazards. It generally calls for exposed live parts to be deenergized unless a stated exception applies and addresses deenergizing, lockout or tagging, verification, qualified persons, and nonconductive ladder side rails near exposed energized parts. Construction work can instead fall under 29 CFR 1926.416 and 29 CFR 1926.417, and an OSHA-approved state plan can also apply. Use the rules that cover the employer and task.

The field plan should state:

• circuit or source identification and who may disconnect it;
• deenergization, lockout or tagging, absence-of-voltage verification, and reenergization steps appropriate to the task;
• ladder, ceiling, attic, wet-area, occupant, pet, furniture, and access controls;
• which alarm coverage is temporarily out of service and the replacement sequence;
• whether occupants, property staff, a monitoring provider, or the fire department must be notified before testing or impairment;
• how false dispatch, building evacuation, or unintended system activation will be prevented without leaving protection disabled;
• stop-work conditions for unidentified wiring, damaged boxes, water, overheated conductors, inaccessible equipment, system devices, or a scope that requires another license; and
• who confirms that power, backup, devices, interconnection, and any monitoring status are restored.

Use a safety inspection checklist when access and electrical conditions need a short pre-task record. For a higher-risk or multi-step job, the work-order safety briefing guide shows how to connect hazards, controls, scope, and crew review without turning a small service visit into a binder exercise.

An active CO alarm is not a routine “chirping detector” replacement call. Carbon monoxide is invisible and odorless. If a CO alarm sounds, follow the device instructions and local emergency guidance rather than silencing the unit and continuing the survey. UL’s CO-alarm guidance says to move everyone to fresh air, account for the occupants, call emergency services, and stay out until responders permit reentry. EPA guidance also calls for immediate fresh air and prompt medical attention when symptoms suggest exposure. The work order should record the emergency handoff, not diagnose the source beyond the technician’s authorized scope.

Write stop points for what the survey can uncover

Alarm replacement looks fixed-price until the first base comes off.

Use a written change order or documented exception when the crew finds a condition that changes price, method, safety, approval, or schedule, such as:

• the device is a system detector, notification appliance, relay, or monitored component rather than a household alarm;
• the count, room use, sleeping-area layout, fuel-fired equipment, garage connection, or required location differs from the survey;
• the product date, listing, model, power source, interconnect, or compatibility differs from the quoted schedule;
• hardwired equipment lacks the expected source, backup, box, connector, conductor condition, or accessible circuit identification;
• the retained devices will not form the listed interconnection group promised in the quote;
• a required accessibility feature, special notification appliance, or system interface was not disclosed;
• ceiling damage, moisture, contamination, paint, patching, or finish restoration exceeds the stated allowance;
• an area is occupied, locked, unsafe, too high, or unavailable at the agreed time;
• the AHJ, fire department, permit, inspection, sale, rental, or monitoring process requires added work; or
• a device is recalled and its stated remedy changes the planned replacement or disposal path.

Do not use a change order to bill the customer for correcting the shop’s own nonconforming installation. Use it when the approved scope or a condition the agreed survey could not reasonably establish has materially changed.

If the customer declines a recommended device, location, rewiring, system referral, or return visit, record the exact item, reason given, remaining condition, temporary status, and who received the warning. A signature does not make an unsafe condition safe and does not erase duties imposed by law.

Close by device ID, not by invoice quantity

The invoice may say “12 alarms.” The closeout record should say what happened to SA-01 through SA-12.

For each installed or retained device, record:

• final location and device ID;
• manufacturer, model, function, listing, serial or date code where applicable;
• manufacture date, installation date, marked replace-by date, and expected replacement basis;
• power source, backup, and interconnection group;
• old-device disposition and any recall instruction followed;
• manual device-test result;
• interconnection, audible, visual, voice, or other notification result included in scope;
• permit or inspection status;
• exception, inaccessible area, declined recommendation, or return item; and
• representative label, location, and completion photos.

Attach the final schedule to the service report. Tie the invoice to the approved device IDs, added work, and return visits. Use a completion certificate to record the walkthrough and deliverables without asking the customer to certify hidden wiring or code compliance they cannot verify.

The owner handoff should include:

• product instructions for the exact installed models;
• the difference among alarm, trouble, low-battery, end-of-life, voice, and hush indications;
• emergency actions for smoke and CO alarms;
• monthly test and maintenance instructions;
• who replaces batteries and who responds to tenant reports;
• manufacture and replace-by dates;
• warranty and recall contact routes;
• compatible replacement information for the retained network;
• permit, inspection, monitoring, and unresolved-item status; and
• the final device schedule and photos.

Use a separate warranty record to distinguish the shop’s installation workmanship from device life, battery life, manufacturer coverage, monitoring, occupant maintenance, nuisance conditions, and future code changes. The owner-training walkthrough guide helps keep “we showed them” from becoming the only handoff record.

A field-ready alarm replacement checklist

Before closing the work order, confirm:

The goal is not to make a nine-alarm service call look like a fire-alarm engineering project. It is to know which nine devices you touched, why each one belonged there, what replaced it, how it was powered and connected, what test actually ran, and what the owner must do after the truck leaves.

Sources

Local adoption and individual product status still require project-specific verification.

• National Fire Protection Association, NFPA 72, National Fire Alarm and Signaling Code, 2025 edition, especially Chapter 14 for inspection, testing, and maintenance and Chapter 29 for single- and multiple-station alarms and household signaling systems.
• International Code Council, 2024 International Residential Code, Chapter 3, Sections R310 and R311, for model-code listing, installation, location, interconnection, power, alteration, and household-system provisions; local adoption and amendments control the project.
• International Code Council, 2024 International Property Maintenance Code, Chapter 7, Sections 704 and 705, for model existing-building maintenance, records, smoke-alarm replacement, and CO-alarm or detector replacement context; local adoption and amendments control the property.
• UL Solutions, Gas and Smoke Detector Testing and Certification, for the distinctions among UL 217 smoke alarms, UL 268 smoke detectors, UL 2034 CO alarms, and UL 2075 gas detectors.
• UL Solutions, Carbon Monoxide Alarm Considerations for Code Authorities, for household CO-alarm categories, combination listings, manual test controls, standby power, end-of-life indications, installation, and manufacturer-instruction context.
• U.S. Consumer Product Safety Commission, Fire Safety Information Center, for smoke-alarm placement, battery, and ten-year replacement guidance.
• U.S. Consumer Product Safety Commission, CO Alarms, for consumer placement and monthly testing guidance.
• U.S. Consumer Product Safety Commission, Recalls and Product Safety Warnings, accessed July 15, 2026, for current product-specific recall and safety-warning searches and remedies; check the exact model, markings, configuration, and date information at the time of service.
• U.S. Consumer Product Safety Commission, JNHCD combination-device safety warning, July 9, 2026, and Treatlife combination-device recall, June 25, 2026, for current examples of product-specific identification and different interim instructions.
• U.S. Fire Administration, Smoke Alarms, for bedroom, sleeping-area, level, interconnection, testing, battery, nuisance-alarm, and replacement guidance.
• U.S. Fire Administration, Carbon Monoxide Poisoning Prevention, for CO hazard, fuel-burning source, placement, and prevention guidance.
• U.S. Environmental Protection Agency, Protect Your Family and Yourself from Carbon Monoxide Poisoning, for active-alarm, symptom, fresh-air, medical-attention, combustion-source, and qualified-inspection guidance.
• Occupational Safety and Health Administration, 29 CFR 1910.333, Selection and use of work practices, for general-industry electrical deenergization, lockout or tagging, verification, qualified-person, reenergization, and portable-ladder requirements; construction standards and state plans can apply instead.
• Occupational Safety and Health Administration, 29 CFR 1926.416, General requirements and 29 CFR 1926.417, Lockout and tagging of circuits, for construction electrical-hazard and circuit-control context.
• California Legislature, Health and Safety Code §13113.7, for a state-specific example of approved smoke alarms, permit completion, rental-owner duties, entry notice, and fire alarm system distinctions.
• Massachusetts Department of Fire Services, Preparing Your Home for a Smoke and CO Alarm Inspection and Smoke and Carbon Monoxide Alarms, accessed July 15, 2026, for a state-specific sale or transfer certificate and replacement-device example.

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This article is general information, not legal, electrical, fire-protection, code, licensing, product, property-management, medical, or safety advice. Verify the property, adopted requirements, manufacturer’s instructions, product status, permit and inspection path, and emergency procedures with the AHJ, fire department, monitoring provider, property owner, and licensed professionals responsible for the work before acting.