Reset after power outage

Hold down "Energy Saving" and "Lighting" buttons simultaneously for 10 seconds (or top left & right buttons). Display panel returns immediately. Or try pressing the power freeze and vacation buttons for about 3 secs and it worked great.

Free manual for similar named Upstar monitor. https://mans.io/item/Upstar/M280A1

maybe replace intellivent gas control valve:
http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html#intellivent

gene

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Water inside tank-type water heater can remain hot for some time.
That's one advantage of well-insulated tank-type water heaters.
http://waterheatertimer.org/9-ways-to-save-with-water-heater.html

Power outage can be related to failure of gas control.
Unplug stuff when power goes out. And then plug back in after power is restored.
Water heaters with electronics are not protected from surge.
Electronics can blow out during and after power outage. For example nearby lightning strike will cause current to run along household wires. With ordinary power outage, once power is restored, the surge can affect all kinds of electronic circuitry such as timers, water heaters, water softener, treadmill etc.

Sounds like you have intellivent gas control valve:
Open following link to identify gas control, and download typical manual, and download intellivent service manual with troubleshooting, error codes, etc.
http://waterheatertimer.org/How-to-adjust-temperature-on-water-heater.html#intelli

Take a moment and vote on answer:
And take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.

I simply press and hold the top left and top right buttons (which are for the temp in each section) for about 5 seconds to reset. It's fine until the next power failure...and I don't want that when I'm on vacation.........

Ideally you have the original operating guide that came with the unit. The guide should show the location of a reset button and explain how to reset it to original factory settings.
If you don't have the guide, open the control door and see if instructions are printed on the inside of the door. If not look for small (usually red) button behind door and depress to reset.

I had a like problem with a HP printer after I returned from vacation. While mine wound up being dead from a power outage while I was away, make sure the power supplly is firmly connected, also try another outlet, as silly as it sounds. but most likely the power supply failed. You can look for a replacement on a popular auction site and expect to pay up to 10 bucks for a OEM unit.

Your machine is set to "Announce" instead of "Answer" mode. The announce mode merely plays an outgoing message but does not record any incoming messages.

Since you neglected to specify the model of your VTech 5.8GHz cordless system I can only suggest you enter it into the search box here to download a copy of the manual to learn how to switch modes.

Actually it sounds like the vacation lock has been enabled. To turn it off press and hold the lock button for 2 seconds and test it out. If this is not it then you will need to replace the logic board and get a surge protector as well. Thanks BB