Hi
This past winter I installed a NOMA THM 501 thermostat. During this past winter season the HEAT worked perfect now that I switched it to COOL the air conditioning does not come on.
If the wires were not connected properly I wuold think that the heat would not work, therefore considering that the heat works the cooling should work as well
Can anyone give me a hand in fixing my dilemma?

Thank you
Giorgio

Hi
This past winter i installed a NOMA THM 501 thermostat. Durring this past winter season the HEAT worked perfect now that i switched it to COOL the air conditioning does not come on.
If the wires were not connected properly i wuold think that the heat would not work, therefore considering that the heat works the cooling should work as well
Can anyone give me a hand in fixing my dilemma?

Thank you
Giorgio

Just because the heat worked has nothing to do with the A/C signal wires at the thermostat being wired correctly. I would revisit the T-stat install FIRST. Check over the wiring and make sure the wiring is absolutely correct. I would also make sure the circuit breaker for the A/C unit is turned on in the home and the fuses/breakers(if so equipped) in the outside disconnect are turned on or in case of fuses tested to be sure they are good.

Thank you for the instantenous reply. I have checked the breaker at the electricla panel in the basement to ensure it is on as well I checked the switch mounted on the exterior wall outside beside the air conditioning unit. They are both turned

Have you got your installation instructions for the tstat? Did it or has it got a jumper from rh to rc? Most units need this jumper