I've never heard of a HP without the backup and there's a reason....the HP can only keep up with the heating chore down to the lower 40s outside. The backup kicks in after that, at a cost. To me that means HPs are best where winter temps are moderate. A HP without backup might be possible in St Croix or Martinique.

No, not all heat pumps are equipped with back up heating strips, but most are. They are generally an extra cost option. I doubt that there are many that are incapable of being equipped with them.

Sometimes, heat pumps installed in locations like South Florida do not have any backup heat. It shaves a little bit of money of off the price of the heat pump and lowers the cost of wiring it in. The heat strips (resistance heating elements) dramatically increase the maximum amount of electric power required by the heat pump, which means much heavier or entirely separate power wiring, which increases the cost of installation.

The Payne model you reference can be equipped with no, 5, 8, or 10 KW resistance heat strips. The last three digits of the model number will tell you how it is equipped. Look at the last column on page 2 of the PDF for the code. If it is 000, there are no heat strips installed.

We have to get our definitions a little better here... NO heat pump condenser comes with heat strips (in a split system). The outdoor unit is where the heat pump is located and the indoor unit is either a gas furnace or airhandler. The airhandler has provisions for multiple sized heat packages...ie 5kw,7.5kw,10,15 and so on. The salesman or installer chooses what electric heat to install (if any), depending on wire & breaker size, how big your meter is, load on the breaker box and so on.

So technically, a heat pump is just the outdoor portion of your system and has NO HEAT in it. The indoor unit has the back up heat and together with the thermostat, they decide when to kick in the aux. heat.

Hope this helps

"we didn't know the basic warranty only covers to 5 ton, our 2 systems add to 5.5ton"

Then each system should be fully covered since if they EACH are below five tons.
Might be worth a lawyers letter if they try to balk.

Five tons is about the upper limit for residential equipment, and they do not want to risk having to repair or replace a 10 ton commercial unit on a house.

Does all Heat Pump have emergency heater? Well, I don't think so........ It depends to the specification of the unit that you buy. In line with the technological development and the increasing awareness of the safety issue, today I see most of new heat pumps come with great safety and back-up features!

Here is a link that might be useful: Heater Information

So if a heat pump is only good without backup to the low 40s (temps) does this mean that if it's say (20 degrees outside) that if the heat pump is cycling on and off that the heat strips are doing all the work? The heat pump itself isn't producing any heat? So you're basically using an electric furnace at this point?

no, you got it wrong.

Heatpumps produce usable heat down to 0 degree's fahrenheit.

Depending on the characteristics of your home (how well insulated, tightness, etc) you may be able to heat your home with straight heat pump down to 20 degrees or even colder.

If its super cold, and you have straight electric, the heat pump run constantly with the electric heat strips in the furnace turning off and on sometimes.

At 17 degrees my heat pump still has a COP of 2.58. That means its producing 2.58 units of heat for every 1 unit of electricity. Heat pumps are very efficient compared to straight electric heat strips.

My heat pump can maintain 70°F inside at 25°F outside, and cycle on/off occasionally ... *without* using the heat strips/auxiliary.

Keep in mind that in normal circumstances the "emergency"/auxiliary heat source is activated during defrosting. It doesn't DO the defrosting, but rather warms the cold air that would otherwise be blowing in the house when the system switches to cooling mode for the defrost cycle.

so last dec/jan when my compressor died, it was bitterly cold both months and I was unknowingly running aux/heat the entire time and my power bill was outrageous, had the heat pump been working correctly, it would NOT have constantly been using aux heat, even at those bitterly cold temps, thus a cheaper electric bill?

Yes

The heater package is ordered separately. I doubt you'll find many (if any) air handlers at Carrier's distribution warehouse that have heat strips factory installed. The heater package comes in a separate box and is field installed 99% of the time.