The medium a/c contained by my house is on the fritz. When I turn it on, the emergency grill comes on and blows out thaw out air. Any suggestions as to what could be wrong? The...

air. Any suggestions as to what could be wrong? The centralized heat is working fine, newly the a/c is not acting right.
Furnace make an "explosion" nouns while running?
Answers:    I don't know where you live...but it's the middle of winter here surrounded by Tennessee. On most newer thermostats, there should be 4 settings...cool, steam, off, and emergency. You mentioned that the emergency warmth is coming on, do you have it set on emergency? Sounds similar to it might be time for a replacement thermostat if you have it set to cool and the emergency roast is activated. You might want to own a certified HAVAC technician come out to your home for an inspection of your heating/cooling system. If you decide to renovation out the thermostat yourself, make sure you cut the power past its sell-by date to the heat pump. Failing to do this can seriously make worse the circuit board in the HVAC. A friend of mine only just had to hold the circuit board replaced in his because he messed up to turn off the breakers to the boil pump.
My worcester 28i occasionally give cold marine mid...
if your a/c and heat run at indistinguishable time, call your heat guy.