Do not know what symbols mean on thermostat. - Daikin BRC2A71 - Simplified Individual Wired Remote Control

A thermostat in electronics general mean that there is a overheating issue..

+ symbol means to add together, - symbol means to subtract one from the other, x means to multiply each, / means to divide.

Do you mean a Venstar T1700 thermostat? If that is the case, the Lock symbol merely indicates that the keypad is locked to keep people from reprogramming the thermostat. This prevents anyone from quickly changing the target temperature or the swing temperature (the temperature at which the unit turns on) for the HVAC system. To unlock the keypad, press and hold the Mode button. Then press both the Up and Down arrows. Release all three buttons when the lock symbol disappears.

If the AC has cooled your apartment to a temperature below the target temperature for the current time period, then the control board of the HVAC may be damaged. (It isn't getting the message and has failed in the on position.) Contact an HVAC repair professional.

If the thermostat is indicating that the room hasn't reached the target temperature, then you should replace your thermostat. The thermistor has failed. (Contact Venstar if the thermostat is less than one year old.)

I hope this helps.

Cindy Wells

That symbol usually means that the a/c unit inside the house has frozen over and it won't start working again until after the ice has melted. I would recommend hiring a repair guy for it though. I had this problem and even after it melted the a/c would still go wonky from time to time. There's a part that you might need replaced on the outside unit.

By unit, do you mean the thermostat? And if so, do you mean the whole face is flashing, or just a heat or cool symbol? And if your talking about the heating/cooling unit, are you talking about a flash on the board?
A thermostat face that is flashing is usually batteries.
A symbol that is flashing on a thermostat indicates a call and is in a delay. There will be a 5 minute delay on calls if the call has been short cycled, powered off and on, etc.
If the symbol continues to flash for an extended amount of time, then the problem is in the furnace, air handler, etc.
If the system is working, but flashing, then it could be the programming of the thermostat.

Copy following link for Lux product manuals
http://www.luxproducts.com/instructionmanuals.php

It might mean that AA batteries needs to be changed.
Or it might mean 2nd stage heating cycle.
Air filter needs to be changed.

Tech assistance 856-234-8803
http://www.luxproducts.com

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

did you push the little reset button on thermostat?

It's one of the model numbe. Please state your exact problem that you're facing.

Fan symbol - defrost (fan only - does not use thermostat)
Fan symbol within a circle - fan forced oven
3 little triangles - static grill (keep oven door open)
3 triangles above the fan symbol - fan grill (keep door closed)

I had this same problem today.  I called Honeywell and they said the flashing broken battery symbol may mean low batteries, or it may mean the battery type is incorrect.  They recommend only non-rechargeable alkaline batteries.  I was using rechargeable NiMH batteries.  Even though they were fully charged, I had the flashing battery symbol and the thermostat relay would not work.  I replaced with alkaline, the flashing battery indicator went out, the thermostat works again.
Odd that it worked for 3 months on the rechargeables after first install. I did notice the broken battery symbol came on after the first few days, but I checked the battery charges and they were good, so I disregarded the symbol until the thermostat stopped working today.  Apparently there is something about the NiMH performance characteristic that the thermostat doesn't like.