What is door lock monitoring, and how do new code requirements affect existing elevators?

Door lock monitoring is an elevator safety requirement in ASME A17.1 that ensures elevators won't operate if there's a mismatch between physical and electric circuit detection of door states. While ASME A17.1 requires DLM for new elevators, ASME A17.3 requires it for existing elevators. Jurisdictions have adopted these codes at different times, providing compliance windows. For example, Florida adopted ASME A17.3 with original compliance by Dec. 31, 2023, extended to Aug. 1, 2025.

How can I determine if my elevators need a door lock monitoring upgrade?

Determine DLM upgrade needs through a professional door lock monitoring assessment. ATIS will assess elevator components like gate switches and door interlocks to verify if they're measured independently. Obtain documented confirmation of assessment results, as some states require proof of compliance for regulatory purposes.

What happens if my elevator isn't compliant with door lock monitoring rules?

Noncompliance can result in regulatory enforcement, elevator shutdowns, or red-tagging that takes elevators out of service. States impose penalties—for example, Nevada fines up to $5,000 for starting work without permits, with each 30-day violation period counting as a separate violation. Noncompliance risks unsafe operations and potentially fatal entrapment accidents.

What states require door lock monitoring for elevators?

DLM requirements vary by jurisdiction. States like New York, Florida, Nevada, and Georgia mandate DLM, while Michigan and Illinois are adopting it. Some jurisdictions require retroactive compliance, others may not adopt the DLM section, and enforcement varies. Check your local Authority Having Jurisdiction (AHJ) codes and regulations to confirm DLM applicability and compliance deadlines.

Inside view of an elevator with closed stainless steel doors, wood-paneled walls, elevator controls, safety and warning signs, and reading lights.

Door Lock Monitoring Assessment for Elevators

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[Summary: A door lock monitoring (DLM) assessment can help you determine your compliance with standards and regulations. ATIS's assessments include asset review and consultations on the next steps. We also perform additional assessments, such as due diligence, condition assessments, and hydraulic oil testing. Our assessments can help you understand whether it's better to complete a DLM retrofit or modernize your elevator.]

As elevator safety requirements evolve, elevator door lock monitoring has become a vital component of compliance and risk management for building owners and property managers. An elevator door lock monitoring assessment is a specialized evaluation that verifies your elevators are protected against dangerous faults that might allow movement with doors open or unlocked. Modern elevator codes, such as ASME A17.1 and A17.3, now require robust systems in most jurisdictions. ATIS goes beyond standard inspections with a suite of advanced elevator door lock monitoring services.

Elevator Door Lock Monitoring Compliance Assessment

DLM Assessment Includes:

Onsite inspection of the elevator
Discussion regarding whether elevators meet code
Consultant advice on next steps

Door lock monitoring systems ensure elevators remain securely stationary until their doors are fully closed. Aligning with ASME A17.3 standards, DLM is now a mandatory requirement in several jurisdictions, including New York, Florida, Nevada, and Georgia. In these states, DLM systems are crucial for elevator door safety compliance. Other jurisdictions, such as the states of Michigan and Illinois, are adopting this critical safety requirement.

Depending on the age of your elevators, they may already be equipped with DLM. In some cases, only a parameter change is required. Through our inspections, we assess the status of your DLM compliance and recommend the most cost-effective solutions. Elevator companies often give only one option, and not at the best price possible. Choose us for unbiased guidance with an elevator door safety assessment you can trust.

Gain insight into the projected capital investment and lifespan of elevator assets within a building. Read more about Due Diligence Assessments
Receive a thorough, on-site inspection to examine your equipment's operational performance, maintenance quality, and anticipated lifespan: Condition and Maintenance Assessment
Clean oil is critical for hydraulic elevators. Schedule an oil test.

How Our Door Lock Monitoring Assessment Adds Value

Many elevator owners aren’t sure if they need new hardware, a parameter update, or a complete system modernization. A precise assessment up front can save you significant money because it gives you insight into the exact upgrades or enhancements your system needs. By understanding the condition and capabilities of your current elevator door monitoring system, you avoid unnecessary modernization.

Our unbiased approach to the process includes:

Verifying the exact type and model of your elevator door monitoring system.
Conducting elevator door safety inspection procedures, like an elevator door lock audit, per the latest local code.
Assessing which changes are required for compliance, such as adding a new elevator door restriction device.
Ensuring that complex and expensive blanket proposals from contractors aren’t accepted if unnecessary.

We recommend a DLM assessment during modernization, compliance reviews, or changes of ownership, as well as prior to key regulatory deadlines. This ensures you're fully informed and able to make decisions in accordance with your system's precise needs.

Frequently Asked Questions

To further understand why door lock monitoring is necessary for your facility, consider these common questions:

Door lock monitoring is an elevator safety requirement established in ASME A17.1 or the Safety Code for Elevators and Escalators. It ensures that the elevator won't automatically perform its operations if there's a mismatch between the physical and electric circuit detection of the elevator doors' state.

For instance, a mismatch could occur if the hoistway door interlock detects that the door is open, but the car door gate switch circuitry indicates that it's closed. This code requirement applies to existing elevators per ASME A17.3.

While ASME A17.1 requires DLM for new elevators, ASME A17.3, or the Safety Code for Existing Elevators and Escalators, requires the same for elevators already in service. Jurisdictions have adopted these codes at different periods, providing facility owners a compliance window. Florida, for example, adopted the 2020 edition of ASME A17.3 with the original compliance deadline on Dec. 31, 2023. This deadline was extended to Aug. 1, 2025.
You can determine if your elevators need a door lock monitoring upgrade through a door lock monitoring assessment. At ATIS, we'll assess your elevator components, such as whether the gate switches and door interlocks are measured independently.
When getting an assessment, obtain documented confirmation. Some states require proof of compliance. Assessments also help you determine whether DLM retrofitting makes sense or if you're better off with getting a modern elevator.
If your elevator isn't compliant with door lock monitoring rules, you can be subject to regulatory enforcement. Violations can result in elevator shutdowns or “red-tagging,” taking the elevator out of service until it is fixed. States also impose penalties.

In Nevada, starting construction, installation, or alteration work before obtaining the required permit can result in an administrative fine of up to $5,000. Each 30-day period during which a violation continues constitutes a separate violation. Work must also be performed by or under the supervision of a certified elevator mechanic. Noncompliance can result in unsafe operations, risking fatal entrapment accidents.
Door lock monitoring requirements vary by jurisdiction, and states may adopt ASME A17.3 with amendments, exceptions, or different compliance timelines. Some jurisdictions require retroactive compliance, while others may not adopt the DLM section or may enforce it differently.
Because requirements can change by state, province, city, and authority having jurisdiction (AHJ), check your local AHJ codes and current regulations to confirm whether DLM applies to your elevators and what compliance deadlines for door lock monitoring you need to meet.

Partner With Us for Compliance and Safety

ATIS offers an expert, unbiased elevator door lock monitoring assessment to equip you with the knowledge you need to make the smartest decisions about elevator door lock monitoring. Our consultants provide you with a complete picture of your compliance status and the full range of available options. We’ll work with your team on-site, provide clear reports, and support you every step of the way, so you never have to wonder if your elevators are up to code or if you’re overpaying for compliance.

Schedule Your DLM Assessment and get answers about your door lock monitoring compliance.

Additional Assessments Available

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From Our Clients

"Currently, the ATIS team have consulted on four (4) elevator modernizations for me and my organization with total costs in excess of $4M. Through these experiences, I’ve grown to realize that Dave Hardin (and his team) embodies the very definition of the word expert. His knowledge of elevator code and equipment surpasses anyone’s I’ve spoken to on the topic. This fact, along with the knowledge that ATIS has no fiscal interest in the equipment or vendors we use, gives me confidence that the recommendations and specifications they provides are always in my organization’s best interests. The expertise, attention to details, accessibility, budget mindfulness, and gregarious personality assures ATIS will be our go to consultants for the foreseeable future."

– Robb Woodruff Assistant Director-Engineering CoxHealth
"I would like to provide my account feedback using ATIS as your elevator inspection company over the last several years. The account team is amazing! The response time to any emails as well as their follow up with my account team and elevator provider’s is second to none. Managing the elevator program for the client would be impossible without ATIS. Their industry knowledge is impressive. We have been able to provide the client large savings on vender quotes for repairs several times utilizing ATIS as a 3rd part in the quote process. The savings have paid for the service the last two years. I highly recommend ATIS to any company needing to manage elevators."

– Tom Cayia, JLL
"The level of customer service that we have experience from ATIS’s field inspector’s, management staff, and back office support team, has been above reproach. They are friendly, helpful, and always professional. It is my opinion that no other company in the elevator inspection industry offers the level of innovation and expertise as does ATIS and I highly recommend them to any company, government entity or AHJ looking for a quality solution for their conveyance inspection program."

– Nicholas A. Kavanagh, Fairfax County VA
"As a partner to Liberty, now ATIS, their team of expert consultants have visited many of our Hotels to assist with due diligence, asset management, modernization and new construction. We have been very pleased with their exceptional level of knowledge, project management and professionalism. In addition, ATIS teams across the portfolio handle hundreds of elevator company improper scope proposals or billing for work that is covered under our service agreements. The engagement & resolution has been swift, spot on and already saved our properties well into the $6 figures for the corrections. We look forward to the team taking over our portfolio of elevators to continue improving the reliability and maintenance of our devices."

– Scot Cameron, Concord Hospitality Enterprises
"Brevard County School Board has used ATIS as our Preferred 3rd Party elevator inspection Vendor since 2015... ATIS has worked with us and our elevator maintenance company to complete the Florida State required elevator inspections at our 31 schools and over 50 elevators and chair lifts. The Safety and compliance of our elevators is a top priority. We feel the Inspection service rendered by ATIS Elevator Inspections, LLC keeps the elevators not only compliant with the Florida State Jurisdiction but, in safe working condition. The Customer Service we receive from the back office staff and Inspectors Onsite with ATIS Elevator Inspec- tions, LLC is friendly, Helpful and informative. We recommend their professional services."

– Robert J. Wiebel, Brevard County School Board
"For the past several years, ATIS has been completing elevator inspections at 140 of our sites with 170 in-service elevators. The services they provide are essential in keeping the elevators safe and up to code for our students and staff. Their team continues to deliver timely service and excellent customer maintenance. Communicating with the District and our elevator maintenance vendors is crucial; ATIS provides this service on all levels. In advance, elevators due for inspection are identified and required testing is coordinated with the District’s timetables and constraints in check. Required State of Florida inspection reports are completed and submitted to ensure compliance. We appreciate their level of attention to our needs and gladly recommend ATIS Elevator Inspections, LLC for the inspection and compliance of your elevators."

– Sue A. Welland, Hillsborough County Public School