Nest Thermostat and Harman P68

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bjb4d5

New Member
Dec 16, 2019
9
Kansas
After watching you tube videos (how I figure out most things in life) I am still needing some advice on an idea that I have. So I am remodeling my basement and plan to install a harman p68. I need to re wire many things down there and now that the drywall is gone in the area where I am going to install my stove I thought about thermostats and ease of use. According to some of the video's I have seen as well as posts on this site, a harman can be wired to a thermostat using RH and W1 to create a "loop" back to the p68. With room temp set on high on the harman unit and the controls set to auto this thermostat will work to control the stove.....is that correct given that i would use a battery powered thermostat?? Now, getting a little more complicated....installing a nest thermostat to this. The difference between the nest and the other thermostats I have seen is that nest will need a common wire run to it as opposed to battery on the other. Nest requires too much power with wifi, etc. SO......if I ran a common wire to power the nest and the other two wires from the back of the harman connected to RH and W1, would it work? Doing the compatibility checker on the nest thermostat home page (I checked the RH, W1, and C wires) and it said it would work......but most sites say the nest will not work with a pellet stove. Any feedback would be appreciated. Thank you.
 
A Nest on its own cannot control a pellet stove. Pellet stoves are millivolt systems and a nest needs 24 volts to operate. It can be done with a little ingenuity and a 24 volt transformer and relay. Here is a pretty good article on how to do it along with the parts needed.
 
After watching you tube videos (how I figure out most things in life) I am still needing some advice on an idea that I have. So I am remodeling my basement and plan to install a harman p68. I need to re wire many things down there and now that the drywall is gone in the area where I am going to install my stove I thought about thermostats and ease of use. According to some of the video's I have seen as well as posts on this site, a harman can be wired to a thermostat using RH and W1 to create a "loop" back to the p68. With room temp set on high on the harman unit and the controls set to auto this thermostat will work to control the stove.....is that correct given that i would use a battery powered thermostat?? Now, getting a little more complicated....installing a nest thermostat to this. The difference between the nest and the other thermostats I have seen is that nest will need a common wire run to it as opposed to battery on the other. Nest requires too much power with wifi, etc. SO......if I ran a common wire to power the nest and the other two wires from the back of the harman connected to RH and W1, would it work? Doing the compatibility checker on the nest thermostat home page (I checked the RH, W1, and C wires) and it said it would work......but most sites say the nest will not work with a pellet stove. Any feedback would be appreciated. Thank you.

I have a nest on my 52i , I used a 24v transformer and fan relay others have used the Honeywell all in one interfaces, basically you wire the room temp sensor through the relay and the Nest is powered via the transformer and when it “calls” it closes the relay.
 

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The nest are nice - I use Sensi thermostats for my heat pumps - but do you really need it for your pellet stove? I use a Luxpro PSP 511 - it’s a 5-2 day programmable stat with 4 periods per day. Quite easy to wire and program, and they run $20-$30 on eBay. No worries about a c-wire like you need for the WiFi thermostats.

I mean, if you want a WiFi stat then go for it with the instructions above, all you need is the transformer kit to power it. But if you’re just looking for easy to program thermostat without WiFi, the Luxpro is great.
 
Very good feedback, thank you! I am not 100% on doing the nest, but it's good to know there is a way and also good to know there are other options. Bcb1 makes a great point about really needing it for the stove. My main objective it just to have something else there besides the wire probe.....given that it is a finished basement. With the walls down to the studs I just wanted to do some homework before moving forward......in their present state I can run wires wherever I need them! Bcb1.....on the Luxpro, you are just running two wires to it and it's powered by batteries, correct? I'm a first timer with a pellet stove and really have appreciated the feedback on this site, thank you!
 
Very good feedback, thank you! I am not 100% on doing the nest, but it's good to know there is a way and also good to know there are other options. Bcb1 makes a great point about really needing it for the stove. My main objective it just to have something else there besides the wire probe.....given that it is a finished basement. With the walls down to the studs I just wanted to do some homework before moving forward......in their present state I can run wires wherever I need them! Bcb1.....on the Luxpro, you are just running two wires to it and it's powered by batteries, correct? I'm a first timer with a pellet stove and really have appreciated the feedback on this site, thank you!

Yes - super simple install! And yes, the Luxpro has 2 AA batteries and they last forever! Seriously I bet a set of 2 batteries must last me for at least 2-3 years. There are two wires running from the thermostat to the pellet stove. I have my pellet stove thermostat mounted right next to my heat pump thermostat, simply because I could easily run the wires from that location.

The two wires from the thermostat are really simple to hook up at the pellet stove. You'll see the Harman temperature probe wires plug in to two terminals on the back of your stove. Just splice one of the thermostat wires into one side, and the other wire into the other side - then plug back in to the stove. The thermostat then acts as a switch - it just completes the circuit to turn the stove on when it calls for heat...and it breaks the circuit when the setpoint is reached to turn the stove off. I can take pictures if you would like.
 
I also use a cheap programmable thermostat. it was 20 bucks at Menards. It's mounted on the wall and when my wife wants to turn the stove on all she has to do is flip the switch on the thermostat to heat and to turn it off flip it to off. It's the exact same thermostat that runs the gas furnace and the controls operate the stove exactly like the furnace. Temperature up and down same as the furnace.
Ron
 
The nest are nice - I use Sensi thermostats for my heat pumps - but do you really need it for your pellet stove? I use a Luxpro PSP 511 - it’s a 5-2 day programmable stat with 4 periods per day. Quite easy to wire and program, and they run $20-$30 on eBay. No worries about a c-wire like you need for the WiFi thermostats.

I mean, if you want a WiFi stat then go for it with the instructions above, all you need is the transformer kit to power it. But if you’re just looking for easy to program thermostat without WiFi, the Luxpro is great.
I have a nest on my 52i , I used a 24v transformer and fan relay others have used the Honeywell all in one interfaces, basically you wire the room temp sensor through the relay and the Nest is powered via the transformer and when it “calls” it closes the relay.
Do you have any pictures of wiring up a nest thermostat to my Harman Accentra pellet stove to get it to work.

Thanks
Brad
 
A Nest on its own cannot control a pellet stove. Pellet stoves are millivolt systems and a nest needs 24 volts to operate. It can be done with a little ingenuity and a 24 volt transformer and relay. Here is a pretty good article on how to do it along with the parts needed.

Are you able to tell to how to wire up a nest thermostat to my Harman accentra pellet stove with a 24 v transformer.

Thanks
Brad
 
Yes - super simple install! And yes, the Luxpro has 2 AA batteries and they last forever! Seriously I bet a set of 2 batteries must last me for at least 2-3 years. There are two wires running from the thermostat to the pellet stove. I have my pellet stove thermostat mounted right next to my heat pump thermostat, simply because I could easily run the wires from that location.

The two wires from the thermostat are really simple to hook up at the pellet stove. You'll see the Harman temperature probe wires plug in to two terminals on the back of your stove. Just splice one of the thermostat wires into one side, and the other wire into the other side - then plug back in to the stove. The thermostat then acts as a switch - it just completes the circuit to turn the stove on when it calls for heat...and it breaks the circuit when the setpoint is reached to turn the stove off. I can take pictures if you would like.

I also use a Lux DMH110 on both my stoves. It is especially handy for the main floor as I have the thermostat located in my office, about half way along the length of my house. It's just a simple one - I don't need any programming. I like that it has a "Save" button that automatically lowers the set temp by 5* when pressed once, then push it again and it raises it back to the original set point. I don't use the feature very often, but it is handy when I want it.

It uses the W and RH for the wire and has a jumper between RH and RC

This is how I have the wires set up to the stove/probe

Thermostat wired to P43-notated.jpg
 
I have a nest on my 52i , I used a 24v transformer and fan relay others have used the Honeywell all in one interfaces, basically you wire the room temp sensor through the relay and the Nest is powered via the transformer and when it “calls” it closes the relay.
@Montecarlossfan I recently purchased a Harman accentra 52i insert. I have my nest thermostat wired to a 24v relay but cannot figure out how to connect to the stove. The stove has the touch screen thermostat. Does yours have that? I am trying to have it wired up as the “aux heat” for my heat pump. When the outside temp gets below 30° I want the nest to switch to the stove. Do you have a picture of how it’s wired to the temp sensor?
 
@Montecarlossfan I recently purchased a Harman accentra 52i insert. I have my nest thermostat wired to a 24v relay but cannot figure out how to connect to the stove. The stove has the touch screen thermostat. Does yours have that? I am trying to have it wired up as the “aux heat” for my heat pump. When the outside temp gets below 30° I want the nest to switch to the stove. Do you have a picture of how it’s wired to the temp sensor?
Well not so sure on the 52i-tc although that stove is remote sensor capable. Essentially on the older version you break the connection to the temp probe inline with a relay that closes that connection when the nest calls for heat. I’m not sure the tc version works this way but it might.