Appollo Heater - Does not blow hot air

[Pomah25]

How are you, hopefully i am posting this in the right place.

I have an Apollo water heater, when i turned the heat on the other day, the air coming out of the vents is barely warm air. It heats the house, but takes forever and the heater is constantly running.

I did some googling, and some of the things that i read said to change the air filter(done) and to turn the water temp up (done). The water temp is so hot, that when i have to turn hot water on i also have to run cold water just to be able to use without scalding myself. None of it seemed to help, the air coming out the ducts i still barely warm. Does anyone have any suggestions?

My water heater is 50 gallons (same as originally installed)

If i need to provide more info, just let me know what you need.
Thank you so much in advance!

[Pomah25]

checked the temp coming out of the vents and its about 79.8 degrees, according to all the research i did it should be about 95 or so. Not sure what to do...

It looks like the heating unit is made by First Co. out of Dallas Texas and Model number is 30VAq3 3DVAQ3. Any help would be greatly appreciated.