Why did they sabotage the invention?

The heat pump thermostat

For the technically challenged, the heat pump is the greatest invention ever for heating your house affordably with electricity. For every kilowatt-hour of energy it consumes, it delivers as much as four kilowatt-hours heat equivalent to your home interior. This is because it fetches heat energy from the cooler outdoor environment, raises it’s temperature by a compression process, and delivers it into your home. At the flick of a switch on the thermostat, it reverses itself to become a central air conditioner in the summer months.

The fly in this miraculous ointment is the stupid thermostats that they install with the heat pump. These all have a feature called “emergency” or “auxiliary” heat. This feature turns on an array of cheap energy-hog resistance heating elements to help the heat pump speed heating the house when the temperature setting is raised or in case the heat pump mechanism fails.

Now, I admit some benefit in having emergency back up elements in case your heat pump compressor fails on a frigid night in Fargo. The stupid part of this feature is that the thermostats are designed and default programmed to almost guarantee that the energy-hog emergency heat comes on eagerly all the time when it doesn’t need to. Apparently the vendors, installers, and thermostat manufacturers have a terror of getting complaints that the heat pump does not blow out warm enough air or that it just takes too long to warm up the house after the temperature has been set down for the night or a weekend away. So, your thermostat is configured to bring on the emergency heat when you tweak it up as little as one or two degrees higher than the current house temperature. Then it keeps it on until the house temperature rises to one or two degrees above the set point. Also there is a manual setting for turning on the auxiliary heat any time you want to as well as accidentally whenever you change modes from cooling to heating. Take heart; there is some relief for some thermostats. Check your thermostat manual; you will have to download one from the Internet since you lost it or were never given one. Actually you may have to download the installation instructions, which is often a separate item, intended for the installer. Many models have a well-obscured procedure to increase the difference between the set point and the actual indoor temperature that triggers the automatic energy hog to come on to maybe five or more degrees. Increase this setting to the maximum. Sometimes it is labeled as a choice between “comfort” and “economy”. Choose “economy”. Then when you’ve had the temperature way down because you’ve been away you may still have to raise it back up in increments so you don’t trigger the energy hog. Be patient though. The mass of structure and furnishings in an average house weighs 40,000 pounds, more or less. It takes a lot of energy to reheat it after it has chilled down. That means a whopper cost if you let your auxiliary resistance heat do it.

Finally here's a tipsheet from my former employer that will give you an option if your thermostat can't be adjusted to reduce the eagerness of auxiliary heat.