New nest constantly in delay mode, temp not dropping

[Fluffernutter]

I put up a new nest thermostat today after thinking the internal battery of the last one had gone bad (3.3v- even after connecting c wire)

I put up the new one and immediately got a very low battery alert. I moved out the aaa batteries and confirmed they were in. I put it back up and went to check the volts from the settings menu- it was only 3.03v. This is new out of the box. After 5 hours I checked again, volts went up but only to 3.214v. 

The air is coming on (blowing cold air) but the temperature is not decreasing. Air filter is new, coils are clean and not frozen, I even used a multimeter on the R and C wire and confirmed it was reading 24V.

The snowflake on the front screen is pulsating, looking that up it seems it is a delay mode? It has been in delay mode for over 5 hours. It seems that the nest is kicking the ac on but then shortly turning off, and then repeating the cycle so often that I'm not actually getting a decrease in temperature.

Is this because the nest says the battery is only at 3.214V - and why is the voltage low when it is receiving the 24V in?

I'm stumped. 

[CoolingWizard]

@Fluffernutter , there are a couple reasons for this type of a problem.  The Nest does not make any decisions about the rate of cooling.  You say you have batteries and that you have a C wire.  The AA batteries are used as a backup source of power and do not get charged or recharged by the Nest Thermostat.  The power to operate your Nest Thermostat comes from the air handler.  The AC voltage from the system to the Thermostat is seldom an even 24 Vac. If you have a voltage sharing problem your AC Step-down transformer might be going bad. If the transformer is not outputting enough voltage or current the thermostat will detect this cease a call for cooling. You need to open the air handler, turn the air conditioner on manually by putting jumper between R and Y, then measure the current and voltage direct off of the transformer.

AC Cooling Wizard

[Fluffernutter · Accepted solution]

I also measured the voltage between  R&Y at the thermostat level and got 26.8V - does that number help at all?

[CoolingWizard]

@Fluffernutter , the reason you see a voltage between R&Y is the the compressor contactor coil has the Common wire attached on the other end. This is how a Nest Learning Thermostat can be charge the battery without a C wire attached; It draws a very low current through a connection path like your system has.

The voltage is not the governing number, it  is the  available current (Amps) that we need to be concerned with. We need to determine if there is a component that is drawing excessive current thus not sharing enough or available for the Nest Thermostat. 

AC Cooling Wizard

[Fluffernutter]

I checked at the transformer and I am getting 110v in and 26v is coming out.