What happens if two digital thermometers are set on the same channel

I can understand when it is very cold outside, the voltage of the battery drops below the point is can service the transmitter (in the thermometer). But if night temperature is not below zero that can't be the cause.
Be aware, even batteries that come with a new device, can be "old". you never know what the battery had to last, before you put it in the device.
I would advice to buy a new battery for the thermometer. Look in the manual, for what the manufacturer advices. But never use manganese (Zinc-Carbon) batteries. Although the alkaline batteries perform bad in cold, it could be the best choice.

go to http://www.taylorusa.com/digital-indoor-outdoor-thermometer-1.html and select the link for the manual (Instruction Book under support info, bottom right)

SearchElf - Find Utilitech Timer Instructions
Here is a link to the instructions.

email me for the instructions manual.
[email protected]

Take the batteries out of both units (the base and the outdoor thermometer). Put the batteries back into the outdoor unit, and then put the batteries back into the base unit. This worked for me.

I found one here at this link,
I got mine here
http://www.smarthome.com/manuals/25078.pdf

You can download/print your manual here:

http://www.thencc.com/westinghouse/LS/Instruction/28011_Manual_2007.pdf

Go to http://www.thencc.com/ncc/support.html and type in 28011 as the model number. Click on the word "instructions" for a .pdf 1 page instruction sheet.

Good luck!
JL

Wireless Digital Thermometer GE5805WS4
Instruction Manual

Buttons and Functions
Button Function
Front of unit:
Min/Max...........displays Min or Max temps recorded
CH(Channel)......changes displayed channel
(hold 3 sec to erase)
Clear................clears memory in Min/max display
Back of unit:
C/F....................Toggle between Celsius
or Fahrenheit temperature display
Scroll.................Remote Channel Scrolling ON/OFF

INSTALLING BATTERIES
IMPORTANT:Read the section SETTING UP THE THERMOMETER before installing the batteries for the first time.

1.Remove the rear cover of thermometer. Install 2 new AA batteries. Replace battery cover.
2.Loosen 4 screws on rear battery cover of the Remote Sensor and slide battery cover off.
3.Install 2 new AA batteries .
4.After batteries are installed, the remote sensor will begin transmitting and automatically register to the Thermometer
(within range) after several minutes. However, you can also press the small button in the battery compartment (labeled Tx) to register the Remote Sensor to the Thermometer immediately
5.Replace battery cover and tighten 4 battery screws. Make ure that the battery cover is fully on and tightened to assure a watertight seal.

SETTING UP THE THERMOMETER
The thermometer can monitor up to two different Remote Sensors on two separate channels. Add-on remote sensors can be purchased separately and are compatible with the GE Wireless Thermometer/Clock (model GE5805WS4) as well as this unit. When first installing, always insert batteries into the Thermometer first, then into the Remote Sensor.
The thermometer uses random security code technology-it will learn the random code of the first Remote Sensor it detects and log in as channel 1. Channel 2 will register in the same way. NOTE: Registered channels will be erased when the batteries of the Thermometer or Remote Sensor are removed. When replacing batteries for a Remote Sensor, remember to clear the corresponding channel of the Thermometer in this way:

1.Remove batteries from the remote sensor (step 2 of installing batterie)
2.Select the channel that you would like to clear by pressing the CH button on the Thermometer until this channel number is displayed.
3.Hold the CH button for 3 seconds to clear the channel
4.Follow steps 3-5

MOUNTING THE REMOTE SENSOR AND THERMOMETER
Remote Sensor is suitable for outdoor mounting (watertight) at a range up to 100 feet from the Thermometer. HOWEVER, HE UNIT SHOULD NOT BE MOUNTED IN A POSITiON WHERE IT WILL BE SUBMERSED IN WATER, OR EXPOSED TO DIRECT SUNLIGHT, OR NEAR OTHER SOURCES OF HEAT OR COLD (I won't bother typing the rest) except for:

LOW Battery icon for the sensor will show up on either the
ch 1 or ch 2 display depending on which sensor is losing battery power.

Battery life 6 months
Temp Range Therm 32 to 122 deg F
Remote Sensor -58 to 158 deg F *
*Alkaline batteries can freeze temporarily at temps below -4 deg F. In this condition, the Remote Sensor cannot accurately transmit temp info to the Thermometer. This limits the effective minimum temp fo the Remote Sensor to -4 deg F

Operational Range....>50ft(and up to 100ft)(less interferances)

RF Channel ....refresh to "---" if no signal received in 60 minutes