Have you or installer checked for gas leaks? Or possible wiring problems. Did it become winter?

First place to start is whether electric usage or electric rates increased (or both). I wouldn’t think a new gas furnace significantly increased electric load/usage, but that should be confirmed with manufacturer. In some areas of the country, you could have gone from a low, all electric house rate to a different rate class with higher kWh rates, or changed rate class for other reasons. It is also possible that your bill is sometimes estimated, and this bill was a true up from your estimated bill to your actual usage. If your usage - as opposed to your electric rate - increased and the increase was not caused by the electric load of the new gas furnace, it is a different inquiry. Could be other changes in use, an electrical error or change associated with the gas furnace installation (improper grounding?) or other cause. If that is the case, your electric company may be able to help you verify that your bill is excessive based on the number/type/use of electric appliances and load and if so, suggest other possible causes. If none of those avenues shed light on the problem, the utility consumer advocate may be able to assist you in dealing with the issue.

Do you have one thermostat or two? Which one did they change (if they did)? And did they mix them up?

Thanks for your comments so far. Yes, we are definitely on heat and not aux heat. We do have 2 thermostats and they are installed correctly. We agree that there's something causing our electric heat to work overtime for some reason. Don't know why yet. We've had the installing company out after install. There's no gas leak and wiring gets inspected by the county tomorrow. We did a large comparison of our daily electric charge from comparing last December and January to this year. So we compared last year's daily electric charge from our electric company and this year's daily charge. We then compared these charges based on the daily temperature so we could compare correctly. The daily electric charges are 50% higher every single day in our comparisons after the furnace was installed. We need to figure out why our heat pump is working overtime.

What brand and model is the new furnace? Is the furnace thermostat set to the fan "on" position?

If the new furnace is a variable speed, it is possible the static pressure is high and the blower is running at a high speed in order to maintain the required air flow.

You stated the thermostat has been wired correctly. But have you checked the air conditioner condenser is not running when the furnace turned on?

You keep saying "electric charges", not electric usage. The charge and the usage only mirror each other if the rate hasn't changed, which is what Shivece (2nd comment) was saying.

Get your usage history from your electric utility.

TD

Only a diagnostic suggestion - turn off the heat pump and get some readings for electric usage. That hopefully would eliminate the possiblity the gas furnace and fan is drawing more than expected. And also give a chance to see if the gas furnace puts out the amount and level of heat expected.

How do I check to see if the heat pump is running on aux heat or back up heat? You are correct that the thermostat is set to "heat". How could I know if its actually running on aux heat?

Thank you for your suggestions. I appreciate the help.

There may or should be a setting on your heat pump itself - separate from the thermostat - to either force the heat pump into resistance mode (aux heat in your case? check manual), to lock out the aux heat entirely, or to set some preference for conditions in which it will go to aux heat. Is it possible some settings on the heat pump were adjusted during the period when the gas furnace was being installed (or the old one not working)?

(Note, you'll have to look at your manual and model-specific info, not something internet folk could guess at)

thanks