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Temperature Guard - Temperature & Power Alarm with Telephone Dialer

Item # VM500-3

This item weighs 1.80lbs.

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Product Description

  • has programmable high and low temperature setpoints.
  • will alert if power is out for 5 minutes or longer
  • can call up to 4 telephone numbers, including pagers.
  • The perfect solution to remotely monitor temperature critical areas.
  • The Temperature Guard will alert you with a telephone call if the temperature exceeds the limits you set.
  • Ideal for monitoring the temperature of computer rooms, server rooms, homes, equipment rooms, and greenhouses.


  • Protect valuable equipment against damage due to low temperature, high temperature, or high humidity. Reduce down time due to equipment failure or power loss. Receive a telephone call and be notified to possible equipment failure or power loss before damage occurs.
  • Program the low temperature limit to protect against heating system failure and help prevent frozen pipes.
  • Program the high temperature limit to protect against air conditioning failure or against the heating system failing to turn off (this has happened).
  • Protect your "Florida" home from mold and mildew damage due to high humidity.
Product Description
The Temperature Guard is a full featured remote temperature monitor and alarm system. The Temperature Guard will monitor the temperature and power wherever it is located. When the Temperature Guard has an alarm, it will dial up to four emergency phone numbers and the integrated voice tells you the temperature and whether the power is on or off. You can also call anytime and hear the temperature. Please see the How to use FAQ for more information.

Key Features:
  • Monitor temperature, monitor humidity (optional), and monitor power. Call and hear status any time.
  • The Temperature Guard makes temperature alarm telephone calls if the temperature goes above the upper limit or below the low limit.
  • The Temperature Guard makes power alarm telephone calls if there is a power loss.
  • Simple to install...plug in a telephone line, plug in the power and turn it on!
  • The Temperature Guard is programmed over the telephone following voice menus
  • Programmable low and high temperature alarm limits.
  • Programmable low and high humidity alarm limits. (optional)
  • Records maximum and minimum temperature, humidity values.
  • Record a 10 second personal identification message over the phone.
  • Works with most telephone pagers.
  • Operates with an answering machine on the same phone line.


How to use the Temperature Guard
1) Locate the Temperature Guard (TG) in the area where you want to monitor the temperature.
2) Plug in the phone line and power pack and then turn the TG on.
3) Call the TG from another phone, or cell phone.
4) Follow the spoken instructions and the manual to program at least the following items:
The phone number(s) where you want the TG to call you in case of emergencies.
The upper and lower temperature limits.
5) Hang up by pressing the "0" key until the TG says "Good-bye".
6) That's it. The TG is now monitoring your home or business!

What happens when the temperature goes out of programmed limits?
1) The TG begins to make emergency phone calls starting with the primary phone number.
2) If a person or answering machine answers the phone at the primary phone number, then the TG will say, "Warning the temperature is xx degrees. Please enter you PIN number." xx is the temperature in degrees F. If an answering machine answers, the TG will wait until your greeting message is over, and then it will leave the "Warning..." message.
3) The TG will wait for a valid PIN number.
4) If a valid PIN number is entered, then the TG will stop making emergency phone calls.
5) If a valid PIN number is not entered or an answering machine answers, then the TG will continue making emergency phone calls with the second programmed phone number.
6) Once all the programmed phone numbers have been called the TG will wait twenty minutes and begin making phone calls starting with the primary number.
7) Steps 1) through 6) are repeated until someone enters a valid PIN number or the temperature goes back to within limits.
8) If a new alarm condition occurs, steps 1 through 7 are repeated again.

Can a Temperature Guard and an answering machine share the same line?
Yes, most answering machines answer the phone on the 4th ring. To have the answering machine answer the phone, program the Temperature Guard to answer the phone on the 5th ring. To access the Temperature Guard, call your home and let the phone ring 3 times. Hang up and wait 20 seconds. Call your home again and on the 2nd ring the Temperature Guard will answer.

What do I need to do to store my unit when I am not going to use it for a long time?
Make sure you turn off your unit for storage. When you are ready to use it again, plug it in a few days before you need it to allow the battery to fully charge.

I purchased a Temperature Guard last year. Is there anything that I need to do to get it ready for this winter?
Charge the battery prior to leaving, by plugging the Guard in allowing it to charge for several days.

How do I reset the max and min temperature readings on my Temperature Guard model VM500-3 (and humidity readings on a VM500-3HT)?
To reset all max and min values on your unit, press 9 at the main menu. This option is NOT spoken. Pressing 9 will set the max and min readings to the current temperature (and current relative humidity on models equipped with humidity sensing).

Note: after pressing 9 you will be immediately returned to the main menu. Press 1 to hear the current status of temperature, humidity (if equipped) and power. The temperature and humidity high and low readings will be the same.

Battery Frequently Asked Questions

How long does it take to charge the batteries?
The standard four hour battery backup takes approximately four to seven days to become fully charged. Tests have shown that after one week of charging, the battery lasted six hours, dialing two phone numbers every twenty minutes.

The twenty and thirty hour batteries take approximately two weeks to become fully charged. Tests have shown that after three weeks of charging, the thirty-hour battery lasted fifty hours, dialing two phone numbers every twenty minutes.

I ordered a 20 or 30 hour battery, where is it?
The optional batteries are installed internally at the factory, no user installation is necessary.

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