How do i tell how much power ... kwh ...electric ... for cost of use analysis ... what's a good thermostat degree of heat selection for a room that's now 40 degrees wi/ room size = 40X30X10

Your thermostat should have an emergency heat setting. Putting the thermostat in that position should make the electric heat strips only work and keep the compressor from coming on. If your thermostat doesn't have an emergency heat selection disconnect the compressor outside at the power source. Turn the thermostat 5 degrees Above the Rim temperature the electric heat strips should come on.

Sorry but there is no current cost - it depends on your supplier and which tariff you are on. If you have a smart electricity meter you could even be paying different prices at different times of the day or days of the week.
Such is the current state of the market almost everyone in a single street could be paying different amounts for electricity.

You need to contact your supplier or look at your electricity bill to discover the cost per unit or kWh (kilowatt-hour). Your 1500 watt heater will consume 1.5 kWh or one and a half units every hour.

the thermostats work from the room temperature and not outside temp
could be a problem with the thermostats or the setting procedure

If you turn your heat on and the temperature is set 3 degrees above what the actual temperature of the room, the auxillary heat will automatically come on. The auxillary heat is an electric heat strip that provides heat to your home while the heat pump is in defrost cycle or if there are extremely low temperatures outside. Try not to set the temperature more than 2 degrees above the actual temperature of the room. Hope this helps.

Sounds like a thermostat problem.

Wattage is a term used to express magnitude of power. A common use is to define the electrical power consumption of your home appliances (check the labels). For example, look at the back label of your kitchen toaster. It might read 120 volts, 60 Hz, and 1200 Watts. The 1200 Watts is the power drawn by your toaster when you turn it on. You can get that (Watts) information for any appliance or device that runs on electricity in your house. That's important because that is the unit of measure the electric company uses to charge you in your electricity bill. The electric company bills your electric consumption in kilowatt-hour (KWH). All they are doing is calculating the watts by the thousands (that's the meaning of "kilo") for every hour you have your appliance turned on. The amount 22 cents per kilowatt-hour is close to how much the electricity is costing today. Back to your toaster, 1200 watts is equal to 1.2kilowatts. If you are using your toaster every day for an hour your monthly consumption is 1.2KWH times 30 days equals to 36KWH. That means at 22 cents per kilowatt-hour your toaster is costing you (36KWH times 22cents/KWH) $7.92 on that month. That's the toaster alone, now you can repeat this exercise for every appliance or device using electricity in your home. Start by just doing an inventory of each, do a log with four columns: (1)Name of the appliance, (2)Location, (3)Watts, and (4)Watts/1000 (to get the number in KW). Make a fifth (5) column and call it Hours. Make a sixth (6) column and call it KWH. Then sit down to estimate (think) for how many hours per month each device is turned on. Now multiply each value of column 4 by its corresponding hour number in column 5. Write the results in column 6. Add the results of column 6 and voila! You just have a pretty good estimate of the total KWH consumed in your home in 30 days. Multiply that by $0.22 (or get the actual cost per KWH from your electric service company) and see how close you are to the actual billing. Hope there is no surprises.

There are the science and engineering definitions of the term watt you can research to come to the same conclusion hereto, I just laid a practical perspective.

Try the Worcester tech help line they are good

make sure it is not telling you room temp, some of the Honeywells, will display room temp over desired temp. check that, if it wont let you switch temp than buy a new one, if you dont have a heat pump a new cheap stat is around 20.00.

1500w / 1000w = 1.5 kwh. Every hour you run (assuming it is at 100% peak power) you use 1.5 kw. Just multiply that rate by how much it your power company charges per kwh.

Estimating high at 10 cents per kwh it would be $1 for every 10 hours you run the heater, or $2.40 per day, or about $72 per month if you ran it 24/7 for 30 days.

It is FAR cheaper to use these types heaters to heat one small room than an entire apartment or house if you are only in one room the majority of the time.

I don't have the book for this particular unit but, check the sequencers that control the electric heat mode, as the regulator heat pump works good. The part may have a time or temperature delay that is too long for you. Also if it has a remote thermostat, check the heat anticipate setting. You will have to check the installation manuel, but its usually .6 to .8, but I don't think that is the problem.