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hvacexpertjoe, HVAC Technician
Category: HVAC
Satisfied Customers: 183
Experience:  I have owned and operated 2 HVAC companies in KY an WV. My background is electrical engineering.
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I just arrived at my old house for first time since winter

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I just arrived at my old house for first time since winter and neither ac unit on the outside will fire up but both furnaces are on. What makes it even more strange is when I turn the thermostat to off the circuit those units are on loses power as in the lights go out until I turn it back on. Any ideas the units and house are 5 years old the units are rheem

hvacexpertjoe :

There can be up to a 10 minute delay between a call for cooling and the outside unit kicking on. Also some rheem units have a pressure switch on the outside unit located near the bottom that is usually red. try pushing this switch in. Does the fan come on in the furnace when the thermostat is set to fan on?

hvacexpertjoe :

Also, what lights are you referring to when you say they go out? LED's on the furnace control board?

Customer: The fan comes on when set to fan on and when set to auto... The fan in the furnace that is. The fan outside never turns on. I have been trying since 4:30 am so we are past the 10 min delay I have two two month olds with me so I was trying to make sure all was working or we are gone before it gets hot today.
Customer: By the lights go out I mean the lights inside my house the hallway and foyer lights share the same circuit as the outside ac units and they lose power when I set the fan to auto and the cool/heat to off. They will come back on when the fans outside try to kick on. One fan blade did rotate about an 8th of a revolution at one point when I was out there. I am checking voltage at the outside box now
Customer: There is no red button either
hvacexpertjoe :

are both outside units on the same circuit?

hvacexpertjoe :

pull the disconnect to one of the outside units and try to set the thermostat to auto. If it trips the breaker try the other one

hvacexpertjoe :

one of those units has a short and is tripping your breakers

Customer: The are on separate breakers and the breakers are not tripping. One unit is getting 122v outside the other is getting 105v
Customer: Even when the lights go out it's not tripping anything they remain out though until I turn the thermostat back to on and a fan tries to kick on
Customer: When you turn off just one unit it dims the lights when both are off it kills the lights by lights I mean hall lights again
hvacexpertjoe :

120? you should have 230v outside at the units

hvacexpertjoe :

maybe something is going on in the main breaker panel to the home?

hvacexpertjoe :

try turning all the breakers off and then on again

Customer: When I turn off the downstairs furnace at the switch on the furnace itself it has the she effect it takes out the whole circuit
hvacexpertjoe :

are you checking voltage at the disconnect? between both legs you should have 230volts

hvacexpertjoe :

if you have 120 at both units it tells me that the main breaker in the home may have something wrong with it

Customer: I was checking it in the outside box that says no fuse in box I would pull out the connector and check inbetween the gap I just created
hvacexpertjoe :

turn the main breaker to the home off and back on. turn both furnaces off at the furnaces, and then recheck the outside voltage please

Customer: 120v
hvacexpertjoe :

do you have 230 volt dryer outlet you can check your meter with?

hvacexpertjoe :

what voltages did you read at the dryer outlet?

Customer: I don't have 230v outlet
Customer: Gas dryer
hvacexpertjoe :

is the stove gas?

Customer: Yes
hvacexpertjoe :

If you have two separate outdoor units that are both only reading 120 volts that tells me there is an issue inside your breaker panel. the main breaker feeds 2 legs of 120 volts to give 230 volts AC. If your meter is accurate either the main power coming into your home has lost 1 leg of 120 volts or the main breaker has an issue

Customer: I get 120 in regular outlets too if that tells you anything
hvacexpertjoe :

At this point I would recommend getting an HVAC tech out to check your main breaker panel

Customer: Ok thanks
hvacexpertjoe :

your welcome. glad i could assist

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