120 Volt AC Wired-In + 9 volt Alkaline Battery Operated
Loud 85 db Alarm
Microprocessor Eliminates Nuisance Alarms
New Universal Smoke Sensing Technology
Power and Alarm LED's
Product End-of-Service Life Warning
2 Tamper Resistant Locking Features
Battery Activation Tab
Quick Draw Battery Drawer
Interconnectable with up to 24 Compatible Devices
Ideal for Homes, Apartments and Mobile Homes
Listed to UL217 Standard
California State Fire Marshal Approved
10 Year Limited Warranty
The USI Electric MDS107 Smoke and Fire Alarm responds quickly to both fast-flaming and slow-smoldering fires to protect your family against deadly threats in the home. Perfect for new or replacement installations, the 120V AC hardwired alarm is suitable for houses, apartments and mobile homes. Universal Smoke Sensing Technology responds 87-percent faster to slow smoldering fires and responds quickest to fast-flaming fires. The alarm is fully interconnectable with all USI and Universal 120V alarms using existing wiring and mounting. Auto sensitivity calibration provides superior nuisance alarm protection and creates consistency in alarm sensitivity.
This alarm has additional automatic features including a self-diagnostics check to ensure proper operation, a sensitivity adjustment for changes in temperature or humidity and an end-of-service life warning that sounds when it's time to replace the battery. The 9-volt alkaline battery (included) continues protection in the event of a power outage. This alarm features a front-loading battery drawer for replacing the battery without removing the alarm from the bracket. Mount the bracket to any standard wiring junction box and use the large mounting base to cover imperfections in drywall. For maximum protection, install an alarm inside every bedroom, outside every sleeping area and on all levels of the dwelling. The USI Electric MDS107 Hardwired Universal Smoke Sensing Smoke and Fire Alarm comes with a 10 year limited warranty.
Warranty: 10 Year Limited Warranty
Alarms Power Source: 120 volt hardwired with battery backup (Battery Included)
Q: WHY DOES MY SMOKE ALARM 'CHIRP' APPROXIMATELY ONCE EVERY MINUTE?
A: The smoke alarm chirps to indicate a "low battery" condition, meaning the battery needs to be replaced. Battery powered smoke alarms will chirp a minimum of 30 days before the battery completely loses power.
AC powered smoke alarms with battery backup will chirp indefinitely assuming AC power is present; if battery power is low, or battery is removed; until a fresh battery is installed. Approved replacement batteries are listed on the back of each smoke alarm and in the user's manual.
Certain model smoke alarms with a silence button (designed to silence the alarm during a nuisance alarm) may chirp to indicate the smoke alarm is in the silence mode. The chirp will stop after approximately 8 minutes and the smoke alarm will return to its normal operation.
Q: WHAT DOES IT MEAN WHEN THE RED LIGHT ON THE ALARM FLASHES APPROXIMATELY ONCE EVERY MINUTE?
A: The flashing red light gives a visual indication that the smoke detector is functioning properly. It also indicates a working battery is connected to the smoke alarm.
Q: WHAT DOES THE CONTINUOUS GREEN LIGHT ON MY SMOKE ALARM INDICATE?
A: When a green light is present on your smoke detector, it means that AC power is currently operating the alarm.
Q: THE GREEN LIGHT ON MY SMOKE ALARM HAS GONE OUT, WHAT DOES THIS MEAN?
A: If the green light on your smoke detector is not on, it means the AC power has been interrupted to the alarm. Check the circuit breaker and AC wiring to make sure power is still reaching the smoke alarm.
Q: HOW CAN I TELL WHICH SMOKE ALARM IN A MULTI-STATION SYSTEM INITIATED THE ALARM?
A: When interconnected alarms are alarming, the smoke alarm which initiated the alarm, either by test button or sensing smoke, will flash the red LED light approximately once per second. The red LED light on the other non-initiated interconnected smoke detectors will not be lit but will sound the alarm.
Q: HOW MANY SMOKE ALARMS OR DEVICES CAN BE INTERCONNECT AT ONE TIME?
A: The NFPA 72 standard states the interconnect limit is 12 smoke alarms and up to 6 other alarms (heat alarms or carbon monoxide detectors) for a total of 18 total alarms. With 18 alarms interconnected, up to an additional 6 relay modules may be interconnected (for a maximum of 24 devices).
If battery backup alarms and non-battery backup alarms and accessories are mixed in an interconnect system, all devices without battery backup WILL NOT operate during an AC power failure.
CAUTION: USI alarms and accessories should only be interconnected with other USI alarms and accessories. Connecting devices from another manufacturer to USI devices may result in nuisance alarms, failure to alarm, or damage to one or all of the devices in the interconnect system. All interconnected USI alarms should be powered by the same fuse or circuit breaker. Smoke alarms shall not receive their power from a circuit that is protected by a ground fault circuit interrupter. Improper connection will result in damage to the alarm, failure to operate, or a shock hazard.
If you are interested in ordering a large quantity of items you may qualify for volume pricing discounts. Volume Discount Pricing is a great way for customers to save big on large, bulk orders of most items available in our store. Please send a bulk order request to our friendly sales staff so they may create a quote and provide personal service for your order! You will receive a response within 1-2 business days and our office hours are Monday through Friday, 8am-5pm CST.
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USI Electric Hardwired 2-in-1 Universal Smoke Sensing Smoke and Fire Alarm with Battery Backup
Reviewed: 04/12/2021 by Ha N
Good service and delivery as promised.
Reviewed: 03/29/2021 by MARK S
Good value for dual unit for detection of 2 different types of fires. Also appreciate the added technology to not trigger a false alarm with common household situations. Easy to install with clearly written instructions.
Reviewed: 01/30/2021 by Amir University of Massachusetts Medical school
Work well, easy to replace the old unit with this one.
Reviewed: 10/02/2020 by Rob Warner
Reviewed: 05/04/2020 by Bruce Provo
They are everything I hoped for.simple to install,look good,test easy and not to loud.fast delivery and good price.
Reviewed: 01/06/2020 by Beatriz Penshorn
Excellent service and delivery on time thanks very please to had a business with universalsecuritystore
Reviewed: 06/19/2019 by Dale Steadman
Very Accurate Description
Reviewed: 02/22/2019 by Tom De Martini
This alarm really works. It does respond well to even a small amount of smoke. I accidentally burned some food on the stove top and the alarm about 20 feet away started blaring.
The only thing to realize is the potential for the smoke to get trapped inside an interior compartment of the alarm itself. The alarm will keep blaring if you reinstall it. When this happens there is no way to blow out the trapped air and the alarm must be replaced by a new one. This, however, could be true for any smoke alarm.
Overall this alarm does work very well.
Reviewed: 01/01/2019 by Pietro Dova
Nice to see that the pin connection remains unchanged from 2011. But for some reason the clamping system has changed from prior model so the ceiling mount needs to be replaced with the new one provided to re-attach the unit to the ceiling.
Reviewed: 12/22/2018 by Jake Repash
Easy install and so far have worked good without any false alarms.
Reviewed: 12/08/2018 by Wayne Jertson
I'm very pleased with my new Smoke/Fire alarms. Easy to install and test. Good product!
Replaced 6 Smoke and Fire Alarms
Reviewed: 11/02/2018 by Bruce E. Stuck
I discovered the USI Model 1204 Smoke and Fire Alarm Detectors in my home were 5 years beyond their 10 year lifetime! From information on the detector, I contacted USI, Inc. and was promptly sent an email that contained a video link on replacing the detectors. The link answered all my questions. Hence, I immediately ordered 6 Ea. MDS107 Smoke and Fire Detectors that arrived about 5 days later. I replaced and tested all 6 and they worked perfectly in our alarm system. The efficient assistance provided by Michele Metcalfe at USI, Inc., Owings Mill, Md was superb. Thanks for excellent customer service.
Reviewed: 10/10/2018 by Eugene Smith
First time ordering but was very happy with the quality service.
Reviewed: 10/01/2018 by A.R.
I recently purchased this item directly from USI.
Product arrived as expected and in the condition described on their website.
Excellent Value..... Thanks
Pretty Much Plug and Play
Reviewed: 09/28/2018 by Greg Griffith
Very pleased with warranty support from my old house. I changed out all outdated models in my new home. Simple swap out from one manufacturer to another. 2 mounting screws and a pigtail. Also comes with battery so it's good to go.
New Smoke Alarms
Reviewed: 09/19/2018 by Kevin Kaari
I recently bought 10 new hardwired detectors to replace my existing USI detectors that aged out. The new ones installed quick and easy. No issues with any of them. I am happy with my purchase.
Replace old units
Reviewed: 09/15/2018 by Chester Hewitt
Installation of new smoke and fire detectors was simple and easy, mounted to existing boxes with ease and rewireing was also simple.
Reviewed: 09/10/2018 by Joseph Armstrong
Well satisfied with my purchase! Four units boxed together for shipping. New 9-volt battery included in each unit. Relatively easy to replace / install. MDS107 is well designed and engineered. Battery drawer is a wonderful design change over my original USI detector. Original detectors manufactured in 1999 or 2000. If offered, I would rate my MDS107s as a 6 - Outstanding.
Reviewed: 05/07/2018 by ruth betcher
The alarms installed wonderfully easy. They are great.
Best Ceiling Option
Reviewed: 05/02/2018 by Kristin Pardue
Best option as CO should be monitored down low, not on ceiling.
Replacing old hardwired alarms
Reviewed: 03/23/2018 by Charles Dove
Replaced whole home hardwired ion alarms that were over 10 years old for my parents. Have these alarms in my home for a few months now and am well pleased. Learned from research that photoelectric alarms provide needed coverage in addition to ion technology alarms. These are among the best priced alarms that have both types of sensors.
Reviewed: 03/05/2018 by Phil Gaglia
Your service was excellent and everyone I spoke with was very helpful and professional. It was a pleasure doing business!
Great Service and Product
Reviewed: 01/22/2018 by R B Moreland Jr
great product and customer service. Prompt shipping. Easy installation
Reviewed: 12/03/2016 by Derek Fremd
Had 15-year old USI products and decided to replace as they were long overdue. Good price, fast shipment and super easy install.
Reviewed: 06/03/2016 by Robert Adamski
Great product - Had First Alert's in house and lots of problems. Replaced with USI and no more trouble
Reviewed: 11/28/2015 by Jessica Troutt
We bought four at once and are very pleased. They shipped quickly and were easy to install.