We have a new house with air to air heat pump and electric furnace. We are having trouble getting the house up to temperature at the time selected on the thermostat. The furnace supplier is telling us not to lower the temp during the night and bring it back up in the morning, but it is better and more economical to keep the house at a constant temperature.
Can anyone give some guidance on the best way to operate?
Thank you.

I have to agree with the supplier/manufacturer on this one. A heat pump system is not designed for a programed or manual thermostat that is changing the temp setting to try and save energy. It takes a long time for a heat pump to catch up after a set back and then the problem with kicking on the costly electric heat becomes a problem.

There are pros and cons on this subject and some will say lock out the electric resistance heat to solve that problem but that creates a comfort problem in the home and I want to be comfortable.

For comfy sleeping, you may want to drop it a little bit.

Your thermostat manual might say when the backup heat comes on. I've seen some stats that say a difference of 1.8 deg. See the problem?

In a fancier thermosat world you can set the outside temp above which the HP is the only heating allowed to run.

Heat pumps blow out air that is 7 to 10 degrees cooler that a gas furnace, so setting your thermostat back is going to take longer to warm up the house. But unless you are just trying to save energy I would set the thermostat to a setting that is comfortable when just setting around, if you become active and are plenty warm set it back a couple of degrees.

If you use ceiling fans reverse them so that they blow the air upwards, thie will get the warm air back to the floor and yet not be as much draft on you.