No heat I purchased the 4-1 Air Conditioner/Dehumidifier/Fan/Heater with remote and never worked. It turns on alright.Blows air but not heat nor cool . Very disappointed in the product.

May be a tstat issue. How about when fan in on position?

Sounds like wiring issue to me. I've delt with units like this and there is a wire lead for fan only and a separate one to run the fan when the unit is cooling or heating. I'm only speculating here but I would bet money that this was improperly installed.

Dont get discouraged though because it sounds like its working (for the most part) if you feel up to the task find the manual and check your connections. Otherwise hire a professional.

A heat pump is an air conditioner that reverses its refrigerant flow. In the cooling mode, the evaporator is cold to the room and its condenser is hot. In the heating mode, a valve reverses the refrigerant flow and makes the evaporator warm and the condenser cold.

With heat pumps that's the way they work. In heat mode they are using the evaporator as the condenser and it blows heat out the front and cold out the back. In cooling mode, a reversing valve switches the gas flow reversing the operation of the coils and it blows cold out the front and heat out the back.

It is normal for a dehumidifier to discharge warm air. A dehumidifier is really an air conditioner - a fan blows humid room air across a cold fin coil that causes the moisture to condense on it and drip into a container - thus cooling AND dehumidifying the air. The cool air is blown over the warm coil and discharged out the back. A dehumidifier WILL normally increase the temperature of the room it is in.
You can do the same thing with sitting an A/C unit on a stool in a room. Room air will be drawn in, cold air will come out the front, hot air out the back and water will drip on the floor. And, the room will get hotter, due to what is called "heat of compression" even though you're running an A/C unit.

sure.

what is your goal hot air, you never said,

got full fan speed? on high>? sure.
got full engine coolant heat 180F or more holding??? if not all is lost.
if car has a heater core water valve is it open>?
are the 2 heater core water tubes both fully hot,(hand test)
yes> good.
now you need air flow through the core (heater)
that means the damper most be open,, is it?

in that order. (heat)
the dampers on hondas can be complex. (10x on electric damper motors , aka, damper actuators)
see part 5 and 6 here
http://www.hondaautomotiveparts.com/auto/jsp/mws/prddisplay.jsp?inputstate=5&catcgry1=ACCORD&catcgry2=2002&catcgry3=2DR+EX&catcgry4=KA4AT&catcgry5=HEATER+UNIT

the fSM covers the complex tests of dampers, and not having
a real FSM makes this near impossible.
why , because your dampers are no like anyothers on earth.
other cars use different types. and are all unique .
unlike CABLES
unlike vacuum servos.
see>?

here are the basics for heat.
http://www.fixkick.com/AirCond/heater.html

check for wiring & compresor

There are 3 possibilities beginning with the most likely problem

1) If your heater heats up for a few minutes and then quits, chances are there is a blockage in the air flow, check for dust and grime blocking the air intake coarse filter , airgun blow to clear accumulated dust and otherwise clean the coarse filter .
2) If the heater fan blows but there is no warm air, the heating element needs renewal ( this happens very rarely)
3)If the fan stalls and the heater heats up and the thermostat kicks in, then this will be not be a DIY job. This is least likely as you said the air cooler works.