trane 181

[masshvacguy]

had a trane 181 with a low heating discharge temp..took readings right under heat exchanger...only in the high 90's with 2 stages running,,,gas valve pressures good,,,inducer motor running on high speed,,,correct oriface,,,economizer closed,,,amps on motor fine

[tjc76]

what is the return air temperature? what is the mfr's specified temperature rise for the unit?

[masshvacguy]

only getting a 25 degree temp difference across heat exchanger..I think it was a minimum of 40 in the paperwork,,,return temp was about 72...other units on same roof,,discharge temp was about 120

[timebuilder]

I'd check the airflow. Sounds like too much air moving.

[chill67]

Just curious, where were you measuring return temp? The reason I ask this

question is because I have seen the return temp. at 70 and the mixed air

temp. much lower than that, especially on new rtu's with economizers that

are closed and still let large amounts of cold air in.