I have a home with the NTI GF 200 combo instantaneous water heater and hydro air furnace all in one, nice unit.  The EnergyGuide label on one side of the unit listed the furnace as NY Thermal GF 200 AFUE 97.1, the mfgrs label also on the unit confirmed this and on the other side was another EnergyGuide label that listed a Navien NPE-240A.  I could find AHRI Certificate for the GF 200 as a furnace with the AFUE of 97.1 but could not find the AHRI certificate for it as a water  heater.   I am pretty sure there is not a Navien inside as I have seen the insides of Naviens and they don't look like this.  The manufacturers brochure lists the AFUE of 97.1 and the EF of 0.97 (UEF 0.96) but there is no mention of Navien.

I heard this model mentioned today can anyone shed some light on this, is Navien associated with this?

I wish we could attach files as I have all the backup I'd love to show, pictures, documents.