I replaced an old analog thermostat when we first moved into our new place. Since then, the new Honeywell thermostat I put in is set to 78 during the day it reads around 82 and won't shut off until it gets dark or rains then it runs and turns off fine.

spoke to my landlord and he seemed upset I replaced the ancient one with a new one said it required a special thermostat to be able to run right. I've never heard of that. There are 4 wires - yellow, red, green and black.

Any ideas?

Gonna need. more info than that. First off, Why did you replace it? As of right now, it seems like something else is going on that's not the stat.

I replaced an old analog thermostat when we first moved into our new place. Since then, the new Honeywell thermostat I put in is set to 78 during the day it reads around 82 and won't shut off until it gets dark or rains then it runs and turns off fine.

spoke to my landlord and he seemed upset I replaced the ancient one with a new one said it required a special thermostat to be able to run right. I've never heard of that. There are 4 wires - yellow, red, green and black.

Any ideas?

Your landlord sounds like a bloody genius. Tell him I have some special lamps(light bulbs) that will make all the 110volt fixtures in the house run off 120volts. This will make all the lights burn more efficiently and save him lots of money. I smell a freaking gold mine to be made off this fella.

Oh, and unless he rigged the thermostat some kinda way. I've never heard of that either. Let Slonezp be your guide. I just supply power to the units. I just chimed in cause it sounds like your landlord is a gullible idiot that I could make money off of. Hell, I will even discount some special volt insulating wire termination devices. They greatly improve the quality and integrity of the homes electrical system.

OK I'm done.

We replaced it cause it was an ancient mercury filled kind and it just didn't seem accurate. It wasn't in long before we replaced it.

It just seems it's reading higher than what it is. We took off the front panel of the Stat and placed it around the house and it seems to read correctly. Just not when it's on the wall. The wall doesn't seem like it's hotter than the rest of the place but I don't have a thermometer to check.

Pic

Is it next to a tv or something else causing it to heat up?

A properly sized air conditioning unit is designed to cycle long hours to remove humidity from the space, and could possibly run all day long depending on the outside temp. Couple things I would recommend before going any further is making sure you have good airflow. First, a clean air filter. Second, a clean condenser coil (outside coil). To clean the condenser coil get some Simple Green. Shut the unit off and spray it on the coil. Let it sit for 5 minutes and hose it down. If that doesn't work, it may be time to have the landlord call his a/c guy. If the evaporator coil (indoor) is dirty, normally they are not easily accessible and would need to be professionally cleaned. They get dirty from no filter, long time between filter changes, and pet hair.

 

Something else to check is warm air circulating behind the wall the thermostat is on. If there is no insulation, stick some in the wall behind the thermostat.

 

As far a the mercury stat, that mercury could have stayed in the glass bulb and done no harm to anybody for the next hundred years. If the new stat has batteries that's fine. If not it's a "power stealing" stat and sometimes they don't work well with newer equipment.

Coils are all clean and it's getting and putting out good airflow. The new Stat does batteries. I'll look into the wall it's mounted on.

Thanks a lot!