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  • Cell Phone Freeze Alarm
  • Monitor your home remotely!
  • MAR-500A
  • MAR-500A Temperature Alarm

MAR500 and MAR501 - Cellular Temperature Alarm Dialer


Product Information

New! Cellular Freeze Alarm System

Cell Phone Freeze Alarm - No Phone Line Required!

The MarCell MAR-500A is a cellular freeze alarm, perfect for applications without a land line. The MAR-500A is perfect for monitoring your vacation home or winter home while unoccupied. The alarm will monitor for power outages as well as temperature and humidity conditions. It communicates via the cellular network to the Sensored Life cloud where users can easily program the alarm points, the alarm contacts and log in at any time to monitor the temperature and humidity levels.


  • No Phone Line Required!
  • Will monitor temperature, power, and humidity.
  • Will send alerts via text, email, and telephone calls.

How often does HomeSitter report in with temperature and humidity data?
HomeSitter checks current temperature and humidity against your settings every 10 seconds. If the current readings are outside of your “safe range”, an alert will be sent immediately. If readings are within your safe range, they are recorded every hour. The MarCELL then calls into the servers every 6 to 8 hours to report the previous period's hourly readings. At that point, this data is displayed on the web site in graph or chart form.

A subscription is required to monitor the property and receive alarm notifications. Service subscriptions are available on a month-to-month, seasonal or annual basis

How does the cellular billing work?
Part of the beauty of the MAR-500A; is that you can turn the cellular connection on and off on a monthly basis so you are only paying for the coverage you need when you need it. You can do this online at any time - quickly, easily and with no hassle.

Billing Options:*
  • Annual: $99.00 ($8.25 per month)
  • Seasonal (4 - 8 month term): $11.95 per month
  • Month to Month: $14.95 per month
*Pricing as of 09/23/15 and subject to change

Product Videos

MarCell Cellular Connected Monitoring System 04:27

The MarCELLĀ® Cellular Connected Monitoring System is a monitor that is based on cellular technology. It can monitor temperature, humidity, and power status. Cottages, homes, business, boats, and many more can all have this device installed to monitor their premise. No phone line or internet connection is required.

  • MarCell Cellul...
    The MarCELLĀ® Cellular Connected Monitoring System is a monitor...

Product Reviews

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  1. Thank you! 5 Star Review

    Posted by on 12th Dec 2015

    Love this product! I am a property manager in Minnesota, so winters can be quite a drain on our resources when we have vacant properties - driving to/from them daily/weekly/monthly to check thermostats to ensure pipes don't freeze - this product allows us to spare those trips by the click of a mouse and touch of a keypad. Thank you!