The intercom light on my GE 2-9451 phone is flashing between green and red

You may need to assign an intercom ID for that unit by pushing one of the intercom buttons at the top.

Unplug all power and phone cables for ten minutes, so that you reset it by draining power, this will clear the error,

Try these first and let me know
Intercom does not function correctly
• Make sure line 1 is connected properly and common to all phones on the system.
• Make sure all phone ID’s (station numbers) involved have been assigned.
Transfer does not function correctly
• Make sure receiver phones (stations) have same line connected.
Intercom indicator turns red and green alternately
• The station address needs to be re-assigned due to a duplicate station address in the system. See “Changing the Phone ID (Station Address)”.
Good luck,
Lee

You need to have the phone join the network that you are in by assigning a station address to the phone. If this the only phone that you have like this, simply remove the plastic cover where the station addresses are to be printed. Beneath this cover there is a small button labled "PROGRAM BUTTON". Use a pen, press this button, then press "INTERCOM" and then label your station (01-16) followed by pressing the # key. This will make the intercom button flash on and off red and then it will stop flashing.

I hope this helps!

I didn't fix it myself. We had a phone technician come out to fix the line outside and that must have solved my problem. Thanks

Thats a common "problem", but its easy to fix. The Intercom lights flashing like that is normal and they will continue to do so until you "assign" the phone its intercom number.  If you have more than one of these phones, go to your other phones, lift the handset and see what intercom number lights on that phone when you do so(the lights/buttons that are flashing). Notate which intercom number that is and move to the next phone. Once you have notated the other intercom numbers go back to the phone you wish to program and push PROGRAM , then push the touch tone key of which intercom number you wish to assign the phone (ie. 1 2 3, etc.), then push MEMORY.  That should do it, and if you need replacements their on Amazon. Good Luck

Each telephone must be connected to line 1 and line 2 for
proper operation. The remaining lines 3 and 4 may — or may not —
be connected to each station as you desire. First plug in the battery, then the phone lines (1 & 2 are mandatory), and third the power cord. If your intercome LED is blinking red and green, then press: STORE IN, followed by "INTERCOM" followed by a free intercom# (i.e., any of the memory buttons 1 through 16 not already assigned to another telephone set. Then wait for the phone to go through its initiation sequence during which it searches each of the four possible lines. After that concludes, you should get dial tone on your active lines. :-) Marco

Remove the plastic speed dial card covering and the speed dial card. Press "program" with a pen tip. Press the intercom button. The lcd display says "address-xx" (probably out of range). Type in a new 2-digit address within range (the number of phones you have), probably 01, 02, 03 or 04. Then press the # key. The intercom light should turn green, and there you have it.

Each telephone must be connected to line 1 and line 2 for
proper operation. The remaining lines 3 and 4 may — or may not —
be connected to each station as you desire. First plug in the battery, then the phone lines (1 & 2 are mandatory), and third the power cord. If your intercome LED is blinking red and green, then press: STORE IN, followed by "INTERCOM" followed by a free intercom# (i.e., any of the memory buttons 1 through 16 not already assigned to another telephone set). Then wait for the phone to go through its initiation sequence during which it searches each of the four possible lines. After that concludes, you should get dial tone on your active lines. :-) Marco

Each telephone must be connected to line 1 and line 2 for
proper operation. The remaining lines 3 and 4 may — or may not —
be connected to each station as you desire. First plug in the battery, then the phone lines (1 & 2 are mandatory), and third the power cord. If your intercome LED is blinking red and green, then press: STORE IN, followed by "INTERCOM" followed by a free intercom# (i.e., any of the memory buttons 1 through 16 not already assigned to another telephone set.) Then wait for the phone to go through its initiation sequence during which it searches each of the four possible lines. After that concludes, you should get dial tone on your active lines. :-) Marco