I have installed one of the above unit for my ac and furnace. While the item works perfectly when only the AC related wires are connected, It just keeps coming on and off continuously, with the exhaust fan being the only thing that comes on and off. I got a technician to come in and look at the wiring to see if I made any error. He confirmed that every connection was right. He left with a comment saying that may be the NOMA is not compatible with my HEIL ULTIMATE furnace.
No I have disconnected the NOMA and conncted my old mercury 2 wire thermostat for the heating only and everything is fine.
Any advice!

Yeah, if you had a technician in to look at the wiring then you should have had him fix the problem.

Mark said it. They should have fixed the problem, whether it be a non compatible thermostat or any other issue. If your old thermostat works, and the new one doesnt(and it is wired correctly), then you need to geta compatible thermostat.

From your owners manual. Call them



Compatibility
Generally, equipment with low voltage control is compatible with the Heating/Cooling Programmable
Thermostat (52-2570-6). For details on compatibility of your particular equipment, please call our
Technical assistance line at 1-888-468-6876.

This should be your model number of thermostat. If not the phone number above is still good for Noma. UPM is the same as Noma. Info and model number found on page 23

http://www.upm-marketing.com/images/productID_16/THM501_Manual_Downloads.pdf