How Do I Know If I Have A Dead Battery. If you have a dead battery inside your thermostat then you see no Power to Thermostat. Weak battery leads to many problems in your heating and cooling system.

Next Test the Alternator. Check Your Battery Cables. There are many ways to increase your batterys lifespan.
This will help ensure a safe jump.
If you have a dead battery inside your thermostat then you see no Power to Thermostat. Do not connect the final black cable clamp to the dead battery. Connect the phones charger and wait until the battery icon. If you see a battery icon your phone is powered off and is chargingIf you see a red light your battery is fully discharged.
