Thermostat Problem

[boykinlp]

I have a programmable thermostat that displays the outside temp too. The outside temp is not registering correctly. I figure the most likely culprit is a faulty outdoor temperature sensor. Here’s the conundrum. This thermostat is about 20 years old and I like the way it works very much. I have NO idea where the outdoor temperature sensor is located or what it may look like. I was thinking that I might turn the thermostat off at the breaker and see if it resets when I flip the breaker back on. Can any of you folks steer me in the right direction? Thanks, in advance, for any advice.
Larry

 

[jeffrefrig]

Outside sensors should be mounted on the North side of a building, when possible. You're in SC, do you have the furnace in the attic or do you have a basement. I've seen some sensors mounted in the combustion air PVC pipe. It pulls in outside air to feed the burner on 90%+ furnaces. I put mine in that pipe as close to the outdoors as possible, but it never read the correct temperature, so I ended up drilling through my basement wall and put it outside. I couldn't get to the North wall, but it's on the NE wall. for a couple hours in the morning the sun hits it and throws it off. I don't have the stat programmed to run at any certain outdoor temp so I don't care. Your sensor may be mounted in the combustion air pipe. My sister lives in SC and her house is one floor on a concrete pad. Seems like a lot of houses down South are on slabs. If you find your furnace, the sensor is at the end of a gray wire, similar to a phone line. Any more info I may be able to help better. Good luck.

 

[mtgianni]

Stuff wears out. I would suspect the sensor rather than the electronics that display it. I doubt a reset would do much but do not know for sure. Weather monitors are cheap and that is how I would go if the thermostat still functions otherwise.

 

[Zuchus]

Outdoor sensor might just need a new battery. Finding it, as you indicated, might be an issue. My thermostat is newer than yours, but here’s a picture of what my sensor looks like, mounted on the side of the house.

 

[AugieTN]

Some of the newer thermostats connect to the internet and can display outdoor temperature via the internet. No outdoor sensor needed/

 

[WR Moore]

My HVAC guy says to avoid programmable thermostats.

 

[LVSteve]

My HVAC guy says to avoid programmable thermostats.

Why is that? I think they are great, especially in the summer. I have them set up to cool the bedrooms before we go to bed.

 

[WR Moore]

Why is that? I think they are great, especially in the summer. I have them set up to cool the bedrooms before we go to bed.

I didn't ask. I was having problems with my heat pump not heating. Even after replacing a fried circuit board. Turned out to be the thermostat, and the name brand replacement didn't work either. He sold me a TopTech 'stat at cost and the heat's been on since.

I expect the dislike is the complications and the electronics. More opportunity for parts to fail/take other things with them.

 

[Rustyt1953]

 

[MTC(SS)Ret]

I just had a new Carrier HVAC system installed and it came with the programmable thermostat but no outdoor temp sensor. (It was available at extra cost) However the programmable feature is great and it is also able to be controlled by an app on my phone. The AUTO feature is great where you can set a temp range and it will heat/cool as required.

 

[DWalt]

I have a digital thermometer, the sensor/transmitter hangs outside in the shade with the readout display inside the house. It is not connected in any way to the inside furnace thermostat. The sensor/transmitter does contain an AA battery which needs to be replaced every few years.

 

[boykinlp]

Outside sensors should be mounted on the North side of a building, when possible. You're in SC, do you have the furnace in the attic or do you have a basement. I've seen some sensors mounted in the combustion air PVC pipe. It pulls in outside air to feed the burner on 90%+ furnaces. I put mine in that pipe as close to the outdoors as possible, but it never read the correct temperature, so I ended up drilling through my basement wall and put it outside. I couldn't get to the North wall, but it's on the NE wall. for a couple hours in the morning the sun hits it and throws it off. I don't have the stat programmed to run at any certain outdoor temp so I don't care. Your sensor may be mounted in the combustion air pipe. My sister lives in SC and her house is one floor on a concrete pad. Seems like a lot of houses down South are on slabs. If you find your furnace, the sensor is at the end of a gray wire, similar to a phone line. Any more info I may be able to help better. Good luck.

There are many houses in SC built on concrete slabs. Mine actually has a crawl space, and that is where my furnace is too. Since I posted yesterday, I searched the web and found out what my outside temperature sensor looks like. I didn’t have time to look for it today, but think it will probably be like yours on the northeast side of my house since that is where my A/C unit and natural gas enters the house. Mine definitely doesn’t have a replaceable battery since I haven’t had to replace it in the 20 plus years.

My HVAC guy says to avoid programmable thermostats.

I have really liked this thermostat, especially when I was working. Being single, in the winter I would set it so it would be cool at night when I slept, heat would come on to be comfortable when I showered, stay colder during the day while I worked, and come back on to be comfortable when I got home until bedtime. The opposite for the summer. It was intuitive and would figure out how early it had to turn itself on depending on outside temperatures to reach the desired temperature.

I just had a new Carrier HVAC system installed and it came with the programmable thermostat but no outdoor temp sensor. (It was available at extra cost) However the programmable feature is great and it is also able to be controlled by an app on my phone. The AUTO feature is great where you can set a temp range and it will heat/cool as required.

I don’t know which one you got, but mine is the Carrier TP-PRH01-A Thermostat - Silver. Being as old as it is, it doesn’t hook up to the internet or have the ability to be controlled by my phone. I, too, like being able to set it so the A/C or heat will come on depending on what the temperature inside the house is, especially last month. Sometimes the A/C was needed during the day and heat at night, and I wouldn’t have to touch the thermostat if I had it set correctly.


Hopefully, I will be able to look for sensor sometime this weekend. While doing my web search last night I believe that I found which sensor I need if I have to replace it. Here it is, I think:

Just a moment...

 

[MTC(SS)Ret]

There are many houses in SC built on concrete slabs. Mine actually has a crawl space, and that is where my furnace is too. Since I posted yesterday, I searched the web and found out what my outside temperature sensor looks like. I didn’t have time to look for it today, but think it will probably be like yours on the northeast side of my house since that is where my A/C unit and natural gas enters the house. Mine definitely doesn’t have a replaceable battery since I haven’t had to replace it in the 20 plus years.



I have really liked this thermostat, especially when I was working. Being single, in the winter I would set it so it would be cool at night when I slept, heat would come on to be comfortable when I showered, stay colder during the day while I worked, and come back on to be comfortable when I got home until bedtime. The opposite for the summer. It was intuitive and would figure out how early it had to turn itself on depending on outside temperatures to reach the desired temperature.



I don’t know which one you got, but mine is the Carrier TP-PRH01-A Thermostat - Silver. Being as old as it is, it doesn’t hook up to the internet or have the ability to be controlled by my phone. I, too, like being able to set it so the A/C or heat will come on depending on what the temperature inside the house is, especially last month. Sometimes the A/C was needed during the day and heat at night, and I wouldn’t have to touch the thermostat if I had it set correctly.


Hopefully, I will be able to look for sensor sometime this weekend. While doing my web search last night I believe that I found which sensor I need if I have to replace it. Here it is, I think:

Just a moment...

The thermostat I got with the system is a Honeywell, sorry I don't know the model number, but it was the standard for the system so probably not very expensive. Just required you have wireless internet so the phone app can control it. Also doesn't need batteries. Oh and it does have a touch screen, not the individual buttons.

 

[Heymatt]

OP, got a pic of your thermostat? Some of the older Carrier Thermidistats had a thermistor hard wired from the air handler and located at the condenser.

 

[BU1]

OP, I have a Carrier thermostat here that is now 26 years old. My outdoor temp sensor is mounted in the condensing unit junction box. Several years ago it did as yours and was not displaying outdoor temp correctly, which affected the operation of the heat pump as it is locked out if the ambient temp is below 35*. I ended up shutting the breaker off to the system for awhile, and it then worked fine, and has not acted up again since then.