Two Thermostats to Control the Same Furnace

[LifeLongWNYer]

Hi guys, I have an unusual question. My daughter and her husband are both school teachers and therefore have a lot of days with no work. I installed a clock thermostat for them, and it works great. The problem is, if they program the times and temperatures for work days, then when they are off, all they can do to get heat during the day it to hit the override. What happens then is they forget to take off the override and the heat stays up all night.

What I'd like to do, is install another thermostat next to the existing one. One would be programed for work days, the other for days with no work. The evening and over night settings for both would be the same, but the morning and day temps would be different.

So, when they have a day off, they would flip a toggle switch to the "no work" position, and when they go back to school, flip it to the "work day" position.

Both thermostats would still need to get power all the time, so they don't use the back up battery in the thermostat and run it dead. What I need to switch is the command to the furnace to start.

So, how do I do this?

JBP






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[jgorm]

Get a switch with as many poles as your thermostat has. Our spend $20-50 on a new thermostat that it's more flexible. My thermostat has about 5 times per day that you can adjust it in the program, and the days of the week. If I hit override, it only runs until the next time point.

 

[Electric_Light]

Get a different thermostat with better features and program courses. The "clock thermostat" sounds like the most basic unit. Many thermostats have a temporary override that overrides only several hours at a time or until the next scheduled scheme.

If you don't turn off the competing thermostat, you'll mess up the predictive programming and become unstable. Whenever the thermostat calls for heat or cool, it keeps track of how the room temperature responds and know when to turn on to hit the set point by the programmed time. If you disconnect the output and let the thermostat "spin out", it thinks the heat is running, but the room temperature isn't going up. You could have undesirable things happen like having the heat come on at 2AM, because it thinks it needs four hours to reach 70F by 6AM. Kinda like popping into the neutral in cruise control without pushing the clutch in.

 

[tfi racing]

My first thought was this should be a no-brainer for educated folks such as teachers,but nevermind...How about trying one of those whizzy I-phone app type wifi t-stats,the kids should be able to get enthusiastic enough about one of those to take a few minutes to figure one out,and be able to command it from work or wherever,even better you can be the one in control no matter where you are,I'm sure you will find that appealing.

 

[volleyball]

I agree with doing the wifi stat. They can be at work and turn up the heat before they leave, or turn on the A/C.
There may be a programmable one that is easy to use but it will never be able to cover all the variables.
I'd go as far as doing some remote controllable lights. That way they can turn on the house lights from outside. Great for those winter evenings when it is overcast and everything is dark.

 

[roscoe2000]

Using a switch between two thermostats would not solve your problem. If they are forgetting to reset the thermostat override, they will forget to switch between stats. A programmable thermostat that can reset with a smart phone would be an option but still would not overcome the human error component. There are some home automation products out there that would help overcome this, but then you must plan on every few years for component updates.

 

[75gmck25]

For the OP - I think you are over-designing the solution, unless I misunderstand the requirements.

There are 7 day and 5/2 (weekend vs. weekday) programmable thermostats sold at all the home store. I chose a Honeywell 5/2 version since I work a Mon-Fri schedule.

If I have a day with a different schedule (for example, today is a holiday for me) I hit the up arrow and turn the heat back up for the day. At the next setback transition it will just go back to the regular 5/2 schedule. I do not have to take it off the override. However, if I want the new temp setting to hold for longer I just push the hold button and it stays indefinitely.

Bruce

 

[Bondo]

Hi guys, I have an unusual question. My daughter and her husband are both school teachers and therefore have a lot of days with no work. I installed a clock thermostat for them, and it works great. The problem is, if they program the times and temperatures for work days, then when they are off, all they can do to get heat during the day it to hit the override. What happens then is they forget to take off the override and the heat stays up all night.

What I'd like to do, is install another thermostat next to the existing one. One would be programed for work days, the other for days with no work. The evening and over night settings for both would be the same, but the morning and day temps would be different.

So, when they have a day off, they would flip a toggle switch to the "no work" position, and when they go back to school, flip it to the "work day" position.

Both thermostats would still need to get power all the time, so they don't use the back up battery in the thermostat and run it dead. What I need to switch is the command to the furnace to start.

So, how do I do this?

JBP

Ayuh,.... If they can't remember to flip the switch they got Now,....

What makes ya think they'll remember to flip another switch you install,..??

 

[404]

You will need 2 tstat control relays. Each tstat controls one relay and the switch controls which relay is in command of the furnace.

 

[shoot summ]

Simple solution, if they change the Tstat have them set a reminder on their smart phone to set it back.

As others have stated you are going to an extreme to fix a behavior problem. Short of something automated adding another stat isn't going to fix that.

Or go the wifi route, I have the Nest and really like it. If they forget they can change it from an app on their smart phone, tablet, or even a PC.

 

[pop pop]

My daughter and her husband are both school teachers. I installed a clock thermostat for them.
What I'd like to do, is install another thermostat.
So, how do I do this?



I suggest that if you give them some "room" they'll grow up and become responsible enough to take care of their needs. After all, they are old enough and smart enough to marry and become teachers.

 

[Rob_b]

why not have 2 T-stats with a common base and switch them out. Have one programmed for home days...another for away days. Change them out as needed...why make it so complicated using relays, switches etc. I my mind, its so simple, but I am a bit simple minded too

 

[volleyball]

They were smart. They went to someone who could know or at least understand of how to easily.
I am grateful my kids consult me for something this important that is out of their scope of expertise.

 

[Kevin C]

On my programable, if you override it only overrides until the next programming event.

I have the day off so I punched the temp up a bit. At 10:30 tonight ( next programmed change) the override will automatically be canceled and the temp will go back to its normal pattern (62°F at night).

The only time I have to remember to turn it down, is if I punch the temp up after 10:30 PM... That will stay warm till the morning.

Its a 7 day programmable, HD special that cost $50 or so ( I think they stopped carrying it). The brand is called RiteTemp. The temp override is easy, the programming is not all that intuitive. Obviously better units have come out in the 8 years since I bought it. It still works fine and does what I want. What I like is that it has four programming periods per day.

So we set it to warm the house when we get up in the morning, set back because we went to work. Warm up when we get home.... And end of the night set back to cool. I suppose thats why the smart T Stats are so popular

 

[nehog]

Two thoughts:

Nest will do this automatically.

Honeywell will reset automatically at the next segment of the program. If I forget to turn down the heat in my shop, when the time for the next segment (four per day, IIRC) it will go back to the program. To fix the temp to a static high temp you have to tell it not to change by going to a manual mode,.

 

[RECox286]

The more complicated you make anything, the more

people will fail to understand or use it, and the more

gadgetry there will be to make it fail.

IE: A good friend of mine had the boiler for the house

heat in his detached garage. Garage was also a wood

shop, and open to use by friends, family and contractors.

Garage was also heated by existing boiler... During the

cooler months while the boiler was working, said friend

noticed his gas bill growing out of proportion...I said:

"why not add a magnetic security door switch to the

pass door, and a sign: 'Keep Door Closed' ? That way if it

isn't closed the boiler won't try to heat the garage." Done

deal...Next fall, my friend calls me up: " no heat, boiler not

working." Me: "Is the garage pass door shut ?" (I hear the

palm of his hand slap his forehead.) People are the same the

world over.

Uncle Bob

 

[LifeLongWNYer]

Thanks for the replies guys. Sorry, was a little busy and forgot to check back.

I'm going with 404's idea of two relays in the burner box. That way, both thermostats stay powered up and keep their programming with the power from the furnace. Switching the entire thermostats will force the one "off line" to go into power failure mode and use the batteries to keep the programming, which will kill them.

I understand about the comments relating to them and their responsibility AND I AGREE, but "it is, what it is" and they are good, really good, at what they do, and not much good at what they don't do. After all, I can take an engine apart and put it back together, but that is about the only thing that I could qualify as a teacher for. I can't teach history, I can't teach math, and I sure as hell can't coach basketball and track.

I appreciate the time you guys took to reply, and thank you. I'll let you know how it works out..... both with the thermostats, AND with the kids.

More news, my daughter is pregnant, my first grandchild, so their concentration is about to get stretched a little thinner!




JBP
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[dw1]

another possibility would be a new T Stat with WiFi, they could have it on Cut Back (Energy Saving Mode) and with a touch of an App on a smart phone, they can adjust the temp before they leave school, you can also turn on lights, ect.

 

[404]

Thanks for the replies guys. Sorry, was a little busy and forgot to check back.

I'm going with 404's idea of two relays in the burner box. That way, both thermostats stay powered up and keep their programming with the power from the furnace. Switching the entire thermostats will force the one "off line" to go into power failure mode and use the batteries to keep the programming, which will kill them.

I understand about the comments relating to them and their responsibility AND I AGREE, but "it is, what it is" and they are good, really good, at what they do, and not much good at what they don't do. After all, I can take an engine apart and put it back together, but that is about the only thing that I could qualify as a teacher for. I can't teach history, I can't teach math, and I sure as hell can't coach basketball and track.

I appreciate the time you guys took to reply, and thank you. I'll let you know how it works out..... both with the thermostats, AND with the kids.

More news, my daughter is pregnant, my first grandchild, so their concentration is about to get stretched a little thinner!




JBP
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You understand my reason for doing it that way perfectly. I don't think you will have any trouble with it.

 

[DC73]

another possibility would be a new T Stat with WiFi, they could have it on Cut Back (Energy Saving Mode) and with a touch of an App on a smart phone, they can adjust the temp before they leave school, you can also turn on lights, ect.

To me, this is the best idea. My Honeywell Wi-Fi thermostat allows me to program each day differently, allows me to change settings with my smart phone from any location, AND allows me to temporarily override with a specific time to return to regular programming. I can also permanently hold a temperature while on vacation and then release the hold before I get home via the smart phone app. Way cool.

DC

 

[ishiboo]

Get a Nest, enjoy the auto away.

 

[89GLH]

My grandparents house was built in 1970, and had this same setup. The AC thermostat was upstairs, furnace thermostat downstairs. They never wanted to pay for dual zones, so up until the day he died they fought about controlling the temperature in the house. What a nightmare.

 

[mmack66]

I don't understand what two thermostats will do that one won't do.

You are still having to program the same number of days.

 

[volleyball]

another possibility would be a new T Stat with WiFi, they could have it on Cut Back (Energy Saving Mode) and with a touch of an App on a smart phone, they can adjust the temp before they leave school, you can also turn on lights, ect.

To me, this is the best idea. My Honeywell Wi-Fi thermostat allows me to program each day differently, allows me to change settings with my smart phone from any location, AND allows me to temporarily override with a specific time to return to regular programming. I can also permanently hold a temperature while on vacation and then release the hold before I get home via the smart phone app. Way cool.

DC

That was mentioned in post 4 and already passed on.

 

[DC73]

That was mentioned in post 4 and already passed on.

Your point? My post was an added value post for the OP who might not be familiar with some of the things you can do with the more advanced thermostats.

DC

 

[LifeLongWNYer]

Thanks again guys, I appreciate the advice. I do understand the features of a programmable thermostat, but what my daughter does has her out of the house for a couple of weeks, then back in the house for a whole week. One programmable thermostat would her her reprogramming it every time she is off for a week, then again when she goes back to work.

She is my daughter, but that won't happen, unless I swing by and do it. I love her dearly, but she has too much time off for me to keep up with that.

404's idea wins the race, as she can handle a single toggle switch. thanks to all.

JBP



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[PT Doc]

If they can't remember to take the stat off hold then why would they remember to pick the right stat for the day?

 

[LifeLongWNYer]

Well, they might not, but at the least they will still be getting SOME setback. If they forget to cancel the hold, the heat stays on forever.

I'm just trying to help the kids save some money. I remember being young and not making much money.


JBP



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[volleyball]

School teachers in NY make a lot more than a lot of other states. Their combined income may exceed yours. But you don't have a lot of their expenses.
Did you do any research for a more programmable T-stat? I bet there is one or more that will handle multiple week formats. Not cheap but less to think about