Digital thermostat resets to ambiant temp

When I use the thermostat to call for heat, the temp resets to ambiant temp in a few moments. At the furnace, the fan starts but the gas fails to ignite. Any thoughts?

Thanks!

You can try replacing the battery and checking the wiring for a loose wire or broken contact.

But, if it's an old thermostat that had been working properly, it may be time to get a new one.

If it's a new thermostat, either it's defective or it's wired up improperly.

Most of the digital thermostats only display one number...they show room tempertature unless you are changing it.