Relize this is an A/C issue but hoping some of you old refrigeration dogs may have some insight!
I have a 7.5 ton York packaged RTU with electric heat. The problem I'm having is it keeps locking out on High limit control --- 9 blinks. I have replaced the air pressure control and the high limit control and thoughly checked all the wires for shorts. From what I understand this unit is designed to lock out even the A/C when this circuit is broke three times in an hour. I have taken the limit wire from the board and put it on red bypassing all the wires and safties and it does not lock out ! There is a total of 4 units on the roof and the other units have done the same thing.
Any and all help would be greatly appreciated !!!
York MD# NM090E36B2BMB3C SN# NGNM085086