Dover DMC Hydraulic Elevator Controllers: Failure Risks and Modernization Options in Western Washington
Your elevator stops on a Monday morning. Our technician traces the problem to a failed circuit board, one the manufacturer stopped supporting in 2019. The board ships to a repair lab, and the earliest your elevator can return to service is three to four weeks away.
If you own a Dover DMC hydraulic elevator, this isn't hypothetical. It's already happening across our portfolio. Here's what's going on, what it could cost you, and how to get ahead of it.
Dover DMC at a glance
The Dover DMC is a microprocessor-based hydraulic elevator controller made by Dover Elevator from 1985 to 2001. It is now obsolete: thyssenkrupp Elevator stopped supporting its main circuit boards in 2019. When a DMC board fails, repair takes three to four weeks at a minimum. Worst case, a failure that wipes out the controller's software could leave the elevator down until it's modernized. Washington Elevator recommends that building owners plan a modernization before a failure forces one.
What is a Dover DMC elevator controller?
Dover Elevator built hydraulic elevators from 1955 until 1999, when the company was purchased by Thyssen. That business became thyssenkrupp Elevator and is now TK Elevator. In Western Washington, Dover equipment was distributed and installed by Sound Elevator, so many buildings across the Puget Sound region, from Everett to Seattle to Tacoma (and beyond), still run on it.
The DMC was Dover's first microprocessor-based hydraulic control system, produced from 1985 to 2001. It was a well-built controller, and its reliability is a big reason so many are still in service today.
The DMC runs on four main printed circuit boards (PCBs) that talk to each other as a communication network:
Power Unit Relay board
CLC board, the "brains" of the system
Door Operator board
Selector board
All four boards must work for the elevator to run. If any one fails, the elevator stops.
Is the Dover DMC obsolete? Why failures are increasing?
The Dover DMC has been declared obsolete by the original equipment manufacturer (OEM) and has exceeded its useful life. In 2019, thyssenkrupp Elevator stopped supporting the main components of the DMC communication network. Today, these controllers are 25 to 40+ years old.
TK Product Availability Notice - 11/15/19
As they age, we're seeing failures increase. We estimate that 5–10% of the DMCs in our portfolio have already experienced a critical failure, meaning something in the communication network has failed, usually one or more of the four boards.
Circuit board failures give no warning. There's no wear to inspect and no way to predict when one will happen. When a failure occurs, here's what follows:
Troubleshooting. Our technicians determine whether a board has failed, and which one.
Lab repair. We send the board to Access Electronics, our third-party repair partner, for inspection, necessary repairs, and testing.
Reinstallation. The repaired board is installed back to the controller. If the repair is successful, we can return the car to service. If not, we continue troubleshooting.
That process takes a minimum of three to four weeks, and that's if there's only one problem. If more than one board has failed, it takes longer. The elevator is out of service the entire time.
So far, we've returned every DMC to service. But each repair depends on a shrinking supply of parts and expertise for decades-old electronics, and we can't promise that record will hold.
What happens if a Dover DMC can't be repaired?
The biggest risk is losing the controller's software. If the software is lost and can't be restored, there's nothing left to repair. The elevator stays down until it's modernized.
A modernization isn't a quick fix. It requires engineering, permitting, and equipment orders before installation can begin. From signed agreement to a working elevator, that typically takes 6-12 months. Planned on your schedule, that's a scheduled outage that takes four to six weeks. Forced by a failure, it's an unplanned one that can last months.
Think about who depends on your elevator: residents with limited mobility, tenants and their customers, deliveries, and staff. In a building with only one elevator, there's no backup.
How do I know if my elevator has a Dover DMC controller?
You may have a DMC if your elevator matches any of these:
It's a hydraulic elevator installed or modernized between about 1985 and 2001.
The controller in the machine room carries the Dover name with a blue cabinet.
It was originally installed by Dover Elevator or Sound Elevator.
Your service records mention boards such as the CLC, Selector, Door Operator or Power Unit Relay.
Your elevator has “Impulse” buttons, a distinctive square button with rounded corners.
Not sure? We can confirm it during a quick site visit.
Dover DMC modernization options
Option 1: Essential Modernization
This is the budget-friendly option. It targets the obsolete components, starting with the controller and code required items. It includes a new controller, landing system (selector), door operator, fixtures, wiring, plus code-required updates such as emergency communication and safety systems, oil line modifications, and a 3D door reopening device.
The hydraulic power unit and hoistway door hardware stay in place to be updated later. Essential modernization costs about 25% less than a Complete Modernization, so you can spread your capital spending over time.
PROS. Up front cost and initial downtime are less. Cost and downtime are spread out. Peace of mind knowing the main areas of concern are addressed.
CONS. Higher total cost when factoring multiple mobilizations and permits. Some older components like the hydraulic system and door hardware are retained and can fail in the future. A robust maintenance plan is critical when choosing this option.
Option 2: Complete Modernization
This is essentially a new elevator. It includes a new controller, landing system, door operator, hoistway door hardware, fixtures, wiring, and power unit. The hydraulic cylinder, cab, rails, and other components are retained. A full modernization gives you another 25+ years of life.
PROS. Full peace of mind knowing you have an completely updated system that you don’t have to worry about for 25+ years.
CONS. Higher up front out of pocket cost and downtime.
Option 3: Run to failure
You do nothing until the elevator breaks. There's no upfront cost, but every failure brings troubleshooting, lab repair costs, and weeks of downtime. Each repaired board goes back into equipment that's 25 to 40+ years old, so the money spent doesn't make the elevator any better or any younger. And if a failed board can't be repaired, you're facing an unplanned modernization.
PROS. No initial out of pocket cost or downtime.
CONS. Your elevator has outdated systems that are destined to fail at an unpredicted time, resulting in unexpected downtime and cost.
Dover DMC Elevator Modernization Options
What is Related Building Work?
Both modernization options (1 and 2) trigger Related Building Work: code-required updates to the building around the elevator, usually done by other trades. Depending on your building, this can include items such as mechanical, electrical, fire / life safety and other general items. More about that here.
We identify these items during our site survey, so you'll know the full scope and budget before you commit. No surprises midway through the project.
Pre-engineered Dover DMC retrofit kits: faster installs, less downtime
Because so many DMCs are still in service, several vendors make pre-engineered equipment designed specifically to replace it. We've partnered with these vendors for their seamless installation and long-term quality and support. For you, that means a shorter planned outage and parts that will be supported for years to come.
MAD Elevator — Dover Impulse Retrofit Kit
Recent Dover DMC modernization projects
Frequently asked questions about the Dover DMC
When did TK Elevator stop supporting the Dover DMC?
thyssenkrupp Elevator, now TK Elevator, stopped supporting the main components of the Dover DMC communication network in 2019. The controller has been declared obsolete by the original equipment manufacturer.
How long does it take to repair a Dover DMC board?
By the time the troubleshooting process has occurred and the board is shipped out and back, a single board repair typically takes at least three to four weeks. If more than one board has failed, it takes longer, and the elevator is out of service the whole time.
Can a failed Dover DMC always be repaired?
No. Most board failures can be repaired by a specialized electronics lab, but repair isn't guaranteed. If the controller's software is lost, the elevator may stay out of service until it's modernized.
What does a Dover DMC modernization include?
An Essential Modernization replaces the controller, landing system, door operator, fixtures, and wiring, plus code-required safety updates. A Complete Modernization also replaces the power unit and hoistway door hardware.
How much does Dover DMC modernization cost?
Cost depends on your building and the scope you choose. An essential modernization typically costs about 25% less than a full modernization. Variables that impact the cost are building location, access, number of openings, capacity and speed. Washington Elevator can provide a budget price after a brief conversation and a firm proposal after a site assessment.
How long will a modernized elevator last?
A full modernization is essentially a new elevator and typically adds 25+ years of service life.
Are aftermarket boards available?
Each of the four boards has many revisions. You will need to know the specific board number. Some of the boards that were installed later in the DMC life-cycle can be purchased from third parties like World Electronics. These are becoming increasingly rare.
Can I purchase or stock used boards?
If you can find used boards through an alternate source (eBay, neighbors, etc), you can certainly purchase those. A couple issues with that include:
These are used boards, 25+ years old. There’s no warrantee or even guarantee that they are functional. Replacing one bad board with another complicates the troubleshooting process.
It’s impossible to predict which board will fail. You could end up investing in parts that are never used. I’d much rather see you put that investment towards a faster timeline for a modernization.
Is financing available?
Yes! Our friends at Origo Capital Group offer financing.
Should you modernize your Dover DMC now?
You know your building best, and we understand that any downtime is disruptive. But with an obsolete, unsupported controller, a critical failure is a matter of when, not if. The choice is between a planned outage on your schedule and an unplanned one on the elevator's.
Modernization also takes time to budget. Whether you work from an annual capital plan or a reserve study, starting the conversation now gives you room to choose the option and timing that fit your building.
Think you have a Dover DMC? Contact Washington Elevator for a site assessment anywhere in the Puget Sound region. We'll confirm what you have, identify any Related Building Work, and give you a written modernization budget for your capital plan.