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Old 12-05-2016, 09:36 AM  
aNYCdb
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Default Wiring an "override" thermostat

I had another idea I wanted to float by folks. Currently in my house in upstate New York I have two zones of heat each with an old style mechanical thermostat (not line voltage). One of the potential issues I'm facing is we occasionally intend to let friends stay with us and I'm worried that if they turn the heat down in one of the zones and forget about it it may result in pipe freezing issues. I recently picked up two new standard 7 day thermostats and a similar wifi enabled version and I was wondering if I could do the following.

1. Replace the two existing thermostats with the 7 day programmable one.
2. Wire the wifi enabled thermostat to both zones and place it in the basement so that I could set it to turn on both zones if the basement went below 35 or so and if needed remotely raise the temperature of the hole house.

My though is that this would enable guests to play with the thermostats upstairs to their hearts content, but give me the piece of mind of having a backup.


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Old 12-05-2016, 10:41 AM  
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I just did this with a house I have out of state just so I could monitor it and also turn the heat up before I got there. I only had one zone though but I have a great peace of mind that I can click on an app to check the temp in the house and outside. I had some problems with wiring because my house was built with 4 wires and no Common (Power) wire to the thermostat because back in 2001 they didn't have these wifi ones. I had to steal my fan wire and convert to common and change it in the furnace. I lost the ability to have the fan only on but it still works like normal with the heat and AC. I am not sure how the two zones works as that is above my abilities.


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Old 12-05-2016, 01:47 PM  
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I just did this with a house I have out of state just so I could monitor it and also turn the heat up before I got there. I only had one zone though but I have a great peace of mind that I can click on an app to check the temp in the house and outside. I had some problems with wiring because my house was built with 4 wires and no Common (Power) wire to the thermostat because back in 2001 they didn't have these wifi ones. I had to steal my fan wire and convert to common and change it in the furnace. I lost the ability to have the fan only on but it still works like normal with the heat and AC. I am not sure how the two zones works as that is above my abilities.
Good to know. I just tore down a bunch of fake paneling on many of the walls, so I think I'm going to rewire anyway.
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Old 12-05-2016, 03:11 PM  
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I just did this with a house I have out of state just so I could monitor it and also turn the heat up before I got there. I only had one zone though but I have a great peace of mind that I can click on an app to check the temp in the house and outside. I had some problems with wiring because my house was built with 4 wires and no Common (Power) wire to the thermostat because back in 2001 they didn't have these wifi ones. I had to steal my fan wire and convert to common and change it in the furnace. I lost the ability to have the fan only on but it still works like normal with the heat and AC. I am not sure how the two zones works as that is above my abilities.
One member had the same issue of not having that common wire.
I tipped him off that sometimes when all wires are not needed, they will be cut back and to reveal a little insulation, you may find excess wires. Other times, they ran the exact number of conductors they needed and there is no other option than to rob the fan wire. check it out if you want to get your fan back.
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Old 12-05-2016, 03:17 PM  
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Originally Posted by aNYCdb View Post
I had another idea I wanted to float by folks. Currently in my house in upstate New York I have two zones of heat each with an old style mechanical thermostat (not line voltage). One of the potential issues I'm facing is we occasionally intend to let friends stay with us and I'm worried that if they turn the heat down in one of the zones and forget about it it may result in pipe freezing issues. I recently picked up two new standard 7 day thermostats and a similar wifi enabled version and I was wondering if I could do the following.

1. Replace the two existing thermostats with the 7 day programmable one.
2. Wire the wifi enabled thermostat to both zones and place it in the basement so that I could set it to turn on both zones if the basement went below 35 or so and if needed remotely raise the temperature of the hole house.

My though is that this would enable guests to play with the thermostats upstairs to their hearts content, but give me the piece of mind of having a backup.
My ? I think your over-thinking this. If wiring allows, replace the mechanical thermostats with programmables that have a password feature but, still allows for a few degrees of adjustment and your all set.
Guest will be able to adjust the temp a few degrees but, will not be allowed to drop the temp so far to allow for freezing. You'll also want the ON/OFF feature to be passworded also.
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Old 12-05-2016, 05:18 PM  
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One member had the same issue of not having that common wire.
I tipped him off that sometimes when all wires are not needed, they will be cut back and to reveal a little insulation, you may find excess wires. Other times, they ran the exact number of conductors they needed and there is no other option than to rob the fan wire. check it out if you want to get your fan back.
Already checked that, was hoping to find a wire hidden in there but no luck. They cheaped out on this one and only ran the 4.
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Old 12-05-2016, 05:26 PM  
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Already checked that, was hoping to find a wire hidden in there but no luck. They cheaped out on this one and only ran the 4.
Can you not just add a bypass switch at the furnace for the fan?
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Old 12-05-2016, 05:28 PM  
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Can you not just add a bypass switch at the furnace for the fan?
What do you mean by bypass switch?
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Old 12-05-2016, 05:36 PM  
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What do you mean by bypass switch?
You must have disconnected the fan wire at the furnace so if you take another power wire thru a switch and back to where the fan was hooked up.
Years ago that is all we had with the old thermostats.
Keep in mind I am only asking.
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Old 12-05-2016, 06:09 PM  
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I had to jump a wire to the fan switch in the furnace so it would come on with the heat. I guess I could put a manual switch for fan only but I don't think I have ever run just the fan by itself before.


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