# Thermostat Setting - Honeywell T6 Pro - ?



## user_12345a (Nov 23, 2014)

You have to have a wire connected to W2 at the furnace and stat to do thermostat controlled staging.

You have to disable the upstage timer on the board too.

The stat can automatically bring on the second stage sensing when first can't keep up before the indoor temperature even drops.

It can shut off the second stage and drop down to first as needed.

It can bring second stage on almost right away if you manually raise the temp up.

Well worth doing.

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"Backup Heat Stages: 0, 1"

This is for heatpump, shouldn't see it in the menu.

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"Also, in the book only there is option #371: Heating Cycle Rate (Stage 2) 1-12. However this does not appear in the thermostat. Is this because the heat stage in #211 is set at 1 rather than 2? Again same question if I change the #221 to 2 (should I?) than what can I get from adjusting #370 and perhaps #371?
"

It won't show up unless configured as two stage and means nothing if it's not wired for 2-stage anyway. See first part of my post.




> Next I see that there is an option # 370: Heating Cycle Rate (Stage 1) 1-12. Mine is set at 6. What does this control and what are the pros & cons of changing this?


It's cycles per hour at 50% load.

Controls length of cycles, the lower the setting, the longer the cycles, both on and off.

Higher number results in less of a temperature swing, more comfortable but harder on the furnace. Less efficient.



When the furnace is properly sized, a cph of 3 is a good setting. The factory default of 6 is way too high, especially for a 2-stage which doesn't need to cycle as much to maintain a comfortable temperature range.



Overall, what your contractor did is absolutely shameful -> giving you a 2-stage furnace and stat that you paid extra for and doing the minimum to get it to work, installing it the same way as a builder's special unit, not thinking.

It's apparently a common problem if these forums are any indication -> they'll sell higher end stuff just to make more commission.

There are other things that may need to be checked:

If you have a/c, the fan speed may need to be altered to get the correct airflow for the size installed. They come from factory set for nearly maximum cfm which can be too high for smaller a/cs.

It may also be wise to clock the gas meter to see if they set the gas pressures properly, let me know if you want more info on that.


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## beenthere (Oct 11, 2008)

Won't get the second stage CPH setting option until you set heat stages to 2.


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## UltraRed (Jan 20, 2018)

So, I should be going for a lower CPH setting as possible? When they fixed the induction motor I asked the tech about this and after he said he doesn't leave the install book for the customer and I said well I'd have looked it up on line anyway he said 6, the default, (1-12) is fine. A higher # is hard on the furnace - I understand that. 

But how, I asked him, does one determine if it should be 3 or 4 or 5 or 6? He really couldn't answer.

So how do I determine which is the proper setting? Why? 

BTW, I don't have the wiring for the the thermostat to control the 2nd stage, that is all at the furnace.

Thanks,

Jim


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## user_12345a (Nov 23, 2014)

The install manual is your property and he shouldn't have removed it. It should stay with the furnace for anyone who gets to work on it.

The way your contractor set up the furnace, you don't get the long cycles. *The entire purpose of getting 2-stage is to get long cycles.*


Lower settings, allow for more of a temperature swing; fewer cycles.

Higher cph setting, longer cycles.

I like 3 cph, this is what I would set most stats to.

You can experiment if you want and see what works best.


You should set the cph for 3 as a start and see if u're happy with it.

Do run a new wire with enough conductors to connect W2, disable the timer.

The house will be much more comfortable this way, especially in very cold weather. 

I hope your warranty is with the manufacturer and not with this arrogant contractor. this type, who takes your property so u can't learn about the equipment you paid for and doesn't answer questions isn't worth your time and hard earned money.


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## UltraRed (Jan 20, 2018)

user_12345a thanks for your reply. (to be clear, the tech did not take the manual, only said he would have...!)

I've set the cph to 4 - recommended by the manufacturer and the contractor, but I'm still trying to understand the whole process given my set-up. I only have 3 wires to the stat. 

So if the stat can only set cph # for stage 1, then how does this affect stage 2? 
In other words, if stage 1 is running longer now, how is stage 2 reacting to that?

If I run one extra wire to the stat then both stages could (with some adjustments to the furnace wiring) run from the stat? How is this better? (Again trying to understand the mechanics of it all...naturally and dangerously curious I am....)

If I'm going to add 1 wire, is there a benefit of adding more? I've heard about outside sensor's which somehow integrate into the system. Can you tell me about them? Does that require a different stat or just a sensor - where would the sensor connect into the system, at the stat or the furnace?

I'm also trying to evaluate how much benefit - over the next 20 yrs or more - these changes will help the functioning of the furnace - stress, cost of fuel, comfort levels, etc.

Thanks again!

Jim


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## UltraRed (Jan 20, 2018)

user_12345a, another question: How does the system (stat & furnace) "know" how long to run the cycle to keep the heat "stable" if it's limited to the number of cph? Sure it will run longer, but how is the decision made to run it for 15 mins vs 20 mins say for example as it get's colder at night?


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## user_12345a (Nov 23, 2014)

The changes won't impact fuel costs but will comfort.

Which wires do you have connected? R, G, W? I assume, no a/c?

Do you have any extra wires you can use?



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"I've set the cph to 4 - recommended by the manufacturer and the contractor, but I'm still trying to understand the whole process given my set-up. "

That's fine, if you find the cycles too short, you can back off to 3.



> In other words, if stage 1 is running longer now, how is stage 2 reacting to that?


Stage 2 will be brought on by the circuit board after the time delay, i think daikin is 12 minutes max and the colder it is the shorter the delay.

You may see more high fire operation set to a lower cph.

However, short cycling the furnace is not a good way to prevent it from switching to second stage unnecessarily.



> If I run one extra wire to the stat then both stages could (with some adjustments to the furnace wiring) run from the stat? How is this better? (Again trying to understand the mechanics of it all...naturally and dangerously curious I am....)


The stat knows when the second stage is required, the board does not.

The board's timer will bring on the second stage a lot when it's not needed, and it won't drop back down, it will stay on high fire until satisfied.

It could be bringing on high for the last couple of minutes of some cycles when low is sufficient to keep the house warm. That's dumb.

The stat will bring the second stage on only when it detects first is insufficient to maintain the setting (it will do this without allowing the room temp to actually drop) and will cycle it as needed to maintain the setting.

The result is a much more comfortable home without temperature swings.

If your furnace was oversized, low may be sufficient even in extremes and the 2-stage stat will not bring on high. Still advantageous.

Lastly, the stat will bring on high right away if you manually raise the temp.

The timer is dumb and has no idea what's going on.


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## user_12345a (Nov 23, 2014)

> Sure it will run longer, but how is the decision made to run it for 15 mins vs 20 mins say for example as it get's colder at night?


It monitors the temperature, how the temp responds to cycling and uses a very complex algorithm to determine run time. Constantly adjusts cycle times to prevent over-shooting.



The cph is at 50% load, that is, 50% on, 50% off to maintain the setting.

It may cycle more at greater than 50% load due to the house cooling down quicker and less at under 50% load, but the on time length won't get too short. 

The actual temp over-rides the algorithm, if it's colder than the setting, it will bring the heat on regardless. It won't cycle if continuous operation is needed to maintain setting.

This is all based on the honeywell literature I've read, i've never bothered to count cycles per hour and see how it changes, I would rather watch paint dry.


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## UltraRed (Jan 20, 2018)

so, until I can run more wire between the furnace and stat, can i use the fan wire for the 2nd stage? as it was explained to me by the installer, the fan wire allows me to turn on the fan only from the stat. if i don't care about that could then that wire be used to turn on the 2nd stage aspect of the stat?


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## UltraRed (Jan 20, 2018)

user_12345a said:


> The stat knows when the second stage is required, the board does not.
> 
> The board's timer will bring on the second stage a lot when it's not needed, and it won't drop back down, it will stay on high fire until satisfied.
> 
> It could be bringing on high for the last couple of minutes of some cycles when low is sufficient to keep the house warm. That's dumb.


So, as it is now the 2nd stage will ALWAYS go on after the timer requirement has been meant? Or will 2nd stage not go on if the 1st stage satisfies the stat setting?

So it seems better to have both stages run from the stat? Seems that if only the 1st stage is needed and is called for that would end up using less gas than if the 2nd stage comes on due to the timer even if it's not really needed??


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## user_12345a (Nov 23, 2014)

> So, as it is now the 2nd stage will ALWAYS go on after the timer requirement has been meant? Or will 2nd stage not go on if the 1st stage satisfies the stat setting?


Yes, with the timer, second stage will always come on after the time delay is finished. If the call for heat ends before the time delay does, it won't run on high.

To sum it up, the timer starts bringing on high fire when it's not cold enough outside to need it and doesn't allow down-staging to low, so it's impossible to get the long cycles you paid more for with this setup.

Your contractor technically didn't do anything wrong, just a question of whether you want to use the furnace to it's full potential or not.

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The fuel consumption is similar either way, on low it burns less gas over a longer time. 

Staging is mainly for comfort. 

You get more consistent heat with thermostat controlled staging. The high only comes on as needed and can be cycled back off, drop back down to low.

As previously mentioned, the new stats like yours do a good job of bringing on high before the temperature drops, so if you set it to 70, it won't be stuck at 68 or 69, *it will still maintain the setting.* 25 years ago this would have been a problem with thermostat controlled staging.

You may find that high fire is rarely actually needed, only a few cold mornings each year and when you manually bump up the temperature.

Continuous operation, supplying heat consistently is a good thing when it comes to comfort and lifespan of the equipment. (cycling is hard on motors, heat exchangers, relays, pressure switches - most of the wear occurs when the machine turns on and off)


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## UltraRed (Jan 20, 2018)

i have 3 wires to the stat. so, until I can run more wire between the furnace and the stat, can i use the fan wire for the 2nd stage? as it was explained to me by the installer, that the fan wire allows me to turn on the fan only from the stat. if i don't care about that could then that wire be used to turn on the 2nd stage aspect of the stat? (i assume then that the fan will turn off and on as needed).


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## user_12345a (Nov 23, 2014)

You can for sure, but have to move the wire on both ends to w2, disable the upstage timer, program the stat for 2-stage operation.

Do it wrong and fuse can blow or worse. 

Given that the heating season is ending soon and this system has no a/c, it may make more sense to leave it connected so you can circulate air in the summer. 

Early fall, run a new wire.

There are add a wire style devices that allow you to put two signals over one wire, but it's best to stay away from them unless pulling a new wire is downright impossible.


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## UltraRed (Jan 20, 2018)

one last question LOL (if you are in Vancovuer, I owe you a lot of coffee!), so if i manually, as i do now, up the stat when i get up in the morning does that effect how the furnace works (stage wise) as compared to programming the stat? i seem to remember seeing that if i manually adjust the stat it goes into 2nd stage sooner / faster?

my wife thinks since we moved the cph (stage 1 only) from 6 to 4 that the furnace is louder in the morning when i move the stat up....i think so as well. is that possible?

we don't program it as i just move it up when i get up...whenever that may be.


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## user_12345a (Nov 23, 2014)

lol not in vancouver but I enjoy doing this so no one owes me anything. (wait, if u're in vancouver, how did you get a mid efficiency furnace?)

Manually raising the temperature, it should run all the time until at the setting, so whether set to 4 or 6 cph, it should be recovering mostly on high.

If you were to program it, the stat would cycle it off a bit to give the house time to absorb the heat - part of their intelligent/adaptive recovery feature.


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## UltraRed (Jan 20, 2018)

i wish i was in vancouver, it's our favorite city....i'm on lummi island, near bellingham.

sounds like it would help to program the stat.


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## user_12345a (Nov 23, 2014)

ah, pretty close to vancouver. yah in canada the minimum efficiency allowed is 90%. 

i actually don't like adaptive recovery since it brings the unit on too early (so it can cycle as it nears the setting) and don't like cycling during recovery. the feature can be disabled

was just saying, it works differently if you program it and leave the intelligent/adaptive recovery/smart response enabled. VS. just raising it manually.

Running on high fire for recovery is desirable, not a problem, it's supposed to do that. a 2-stage stat will bring it on high even faster when temp is manually raised. (but also switch to low when it's at setpoint and continue running a bit)


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