# Honeywell thermostat question



## beenthere (Oct 11, 2008)

It should, try it and find out. I don't use box store thermostats to know the definitive answer to your question.


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## user_12345a (Nov 23, 2014)

The retail honeywells have the cooling cph parameter locked at 3 and there's no way to adjust it.

The heating is adjustable, on that model install instructions there are two equipment type settings; one is the actual type like heatpump, forced air, rad, steam and the second one actually determines cph.

The number selected on this particular one doesn't directly correspond with cycles per hour setting. But they used to use 3 cph for high efficiency heat, 5 or 6 for mid or conventional efficiency, 3 for hot water, 1 for steam and gravity and I assume this hasn't changed.

To adjust cooling swing/cph, you need the professional version of the same thing, models start with TH rather than RTH.


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## jdlevy (Aug 20, 2018)

user_12345a said:


> The retail honeywells have the cooling cph parameter locked at 3 and there's no way to adjust it.


That’s interesting. 3 cph is exactly what I’d use so I guess I’m covered there. 

Is the setting between standard and high efficiency a heat-only setting?

I think what my issue may be is that there’s too low of a differential. It almost feels as though when it it hits 0.5F degrees higher than the setting, it kicks back on, and then quickly gets back down to the set temp (not -0.5F to give a bigger spread), and because of that it’s constantly on and off — espdcially because there’s two zones. I’m wondering if there’s a minimum run time?

I’ve been using two Nest E TStats for a few days prior to installing these, but decided to return them given the overwhelming poor feedback from people here and HVAC pros... I do know the Nest had a much wider range and cooled to 1-1.5F past the set temp. maybe I got too used to that...


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## user_12345a (Nov 23, 2014)

Honeywell does not use fixed differentials. But in general they maintain the indoor temp very close to the setting and will cycle more than a old mercury stat or low quality nest.

Their stats use an advanced algorithm to cycle equipment, and cycles per hour is referenced to 50% load. The actual cycles per hour and swing varies a bit as the operating conditions change.

When the unit has almost no surplus capacity to raise or lower the temp, the swing will be very low.





Check your manual to see all the options - it gives more than standard and high efficiency.


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## jdlevy (Aug 20, 2018)

user_12345a said:


> Check your manual to see all the options - it gives more than standard and high efficiency.


Seems that’s the only option I have (Model RTH6360). 

I’m also finding that it’s cooling to 2 degrees cooler than the set temp, but I understand there may be a variance between a thermometer and tstat.

Generally speaking, will I find more accurate outcomes from a T6 pro? I’m also considering an Ecobee3 Lite if anyone has an opinion on that (esp vs the Nest E).

Thanks all.


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## user_12345a (Nov 23, 2014)

Honeywell makes fine retail stats, the pro would give you the option to adjust cooling cycles per hour. Retail stat is dumbed down.

You should let it run a bit so it adjusts to your house and equipment. It may be okay.

If you choose a different stat, key is to read the full manual before making a decision so you know what it's capabilities are, along with settings you can tweak.

Pic attached showing options. Each option will have a different cycle rate, they probably used the values i listed before.


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## u3b3rg33k (Jul 17, 2018)

you mention multiple zones - can you provide some specs on your envelope (sq ft, insulation quality) and furnace (%efficiency, # of stages, BTU/hr, etc)?


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## jdlevy (Aug 20, 2018)

For sure, thanks for the screenshot! I think my only options would be Standard or High Efficiency, as I have Forced Air Gas.

I’ll give it a few days. If the only thing I’m gaining between Retail and Pro is more settings (vs more accuracy) I think I’m happy with the purchase. Hoping it does in-fact settle in to my equipment! I unfortunately had to rush to make a purchase to be within the Nest return window.


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## user_12345a (Nov 23, 2014)

There may be other differences like warranty length and quality of relays. Fundamentally, it's the same product but stripped down.

Setting 205 should only affect cycle rate*, but they don't tell you what each rate each setting corresponds with.

In heating mode if you notice the cycles are very short on standard, switch it to high efficiency gas. Electric setting would probably cause very short cycles.

*There are other settings - call for fan with call for heat, stages, heating/cooling system type option before 205.


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## jdlevy (Aug 20, 2018)

u3b3rg33k said:


> you mention multiple zones - can you provide some specs on your envelope (sq ft, insulation quality) and furnace (%efficiency, # of stages, BTU/hr, etc)?


1600sqft

Zone 1 cooling 1000sqft, Zone 2 cooling a master BR (600sqft). The master is fully insulated/brand new. The rest of the house is old and not all that insulted (old windows etc). The master cools down QUICK, especially if the other zone is closed, and retains.

Zone 1 tstat is terribly place (near a large picture window), but working with what I’ve got. That’s what initially attracted me to the Nest (sunlight compensation).

Furnace is 1H/1C. I’ll get the BTU and %eff in the morning. Can you actually point me toward where I can find this? Purchased the house with these already in place (2yr old Diakin).


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## jdlevy (Aug 20, 2018)

user_12345a said:


> Setting 205 should only affect cycle rate*, but they don't tell you what each rate each setting corresponds with.


Ahh, interesting.


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## user_12345a (Nov 23, 2014)

The previous generation ones did show the actual cycle rate for heat and you could select cycle rate anywhere from 1 to 9, not just what was shown in manual. 

Attached:


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## user_12345a (Nov 23, 2014)

> Zone 1 tstat is terribly place (near a large picture window), but working with what I’ve got. That’s what initially attracted me to the Nest (sunlight compensation).


Ecobee with remote sensor may be a good option - can be set to average with stat, run 100% off sensor or rely on sensor or stat depending on where occupancy is detected.



> Furnace is 1H/1C. I’ll get the BTU and %eff in the morning. Can you actually point me toward where I can find this? Purchased the house with these already in place (2yr old Diakin).


You have to open the furnace and check the full model number. Check model of a/c too.

2-stage equipment is preferred for zoning, can keep the second stage off until both zones are calling.

Requires right zoning panel to do it though and panel can get set up to activate second stage, not done by stat.

Granted, it wouldn't make sense to replace a 2 year old furnace just to be able to stage it.


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## jdlevy (Aug 20, 2018)

user_12345a said:


> 2-stage equipment is preferred for zoning, can keep the second stage off until both zones are calling.
> 
> Requires right zoning panel to do it though and panel can get set up to activate second stage, not done by stat.
> 
> Granted, it wouldn't make sense to replace a 2 year old furnace just to be able to stage it.


Tell me about it. The system was in before the zoning was in place (the master addition was added after the fact by a builder), and this seemed like their workaround in order to not freeze us out of the bedroom.

The zone board is a Honeywell HZ322.

More unfortunately, zone 1 is only 4-wire so I had to do a G wire swap (and jump to the Y) just to get the Nest to work. Luckily these are battery powered.


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## user_12345a (Nov 23, 2014)

4 wire is normal, even with 2-stage and zoning. panel decides when to call for high based on settings.

you'll be best off with battery powered non-wifi. that would exclude the ecobee, i believe.

Your zoning panel appears to support 2-stage which is a good sign.

Zoning is actually good to have when you have spaces with very different heat loss characteristics.


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## jdlevy (Aug 20, 2018)

user_12345a said:


> 4 wire is normal, even with 2-stage and zoning. panel decides when to call for high based on settings.
> 
> you'll be best off with battery powered non-wifi. that would exclude the ecobee, i believe.
> 
> ...


 interesting. Is there a way to tell if the zoning panel is 1-stage or 2? The wires coming from the furnace are also just 4 (RGWY).

Re the power vs battery, one of my zones does have a live common wire. For the other, I do know that Ecobee has their version of an add a wire (called PEK) that would solve that zone’s issue. It likely works the same way the Fan-to-cool jumper works.


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## user_12345a (Nov 23, 2014)

Your zoning panel like i said before appears to be 2-stage, i looked it up.

Check furnace model number and on equipment terminals, see if you have anything hooked up to W2, Y2.


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## jdlevy (Aug 20, 2018)

user_12345a said:


> on equipment terminals, see if you have anything hooked up to W2, Y2.


I haven't had the chance to open up the furnace, but I can tell you that the Zone board only has 4 wires coming from the furnace (R-G-W-Y). BUT, my apologies, after checking again I realized its not the HZ322, its the HZ311 (which I believe is 1-stage).


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## user_12345a (Nov 23, 2014)

yah, that's not as good.

there is a chance your furnace is two-stage though but is using a timer.


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## jdlevy (Aug 20, 2018)

user_12345a said:


> there is a chance your furnace is two-stage though but is using a timer.


Beats me. I'll definitely look into it further -- thanks again for walking me through that.

Regardless... I'm home today, have both units set to 75F, both zones are hovering right around that temp (a little cooler, but not as low as it had dropped yesterday), and the compressor keeps kicking on and off. Outside temp is a balmy 85F (Atlanta, GA).

The compressor is right outside my office window, so I've been conscious of the on/off... definitely more than 3CPH, though I understand that the CPH may increase in this temp. I think my concern is that that tstats are kicking in RIGHT at 75.1F (maybe 75.5F, I can't tell because my thermometers are still reading less than 75). I don't necessarily want the Tstat to wait for 76F or 77F, I'm OK with it maintaining a constant temp -- just want to ensure its not bad for the compressor and fan.

A secondary concern is that yesterday evening, both units were also set to 75F, and both zones got VERY cool (71-72), even with the Tstats thinking they were at temp.


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## user_12345a (Nov 23, 2014)

To reduce number of cooling cycles, you'll have to get stats with adjustable cooling swing or cycles per hour.

Less cycling is better for the compressor and fans, more maintains a more consistent indoor temp.

I have no explanation for the zones dropping well below the setpoints.


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## jdlevy (Aug 20, 2018)

user_12345a said:


> Less cycling is better for the compressor and fans, more maintains a more consistent indoor temp.


Right. Makes sense. Do you have a model you'd recommend? Would love to stick with Honeywell w/ a UMP for ease, but if I should go with another brand, happy to (plenty of other screw holes behind my units already :laughing:

I keep hearing good things about the Ecobee3 Lite if I did want to go the Wifi route, but I'm also perfectly fine with a 5-2 Programmable. An HVAC tech recommended the T6 Pro but only because thats what he uses the most.



user_12345a said:


> I have no explanation for the zones dropping well below the setpoints.


I think its just inaccurate temp reading at the Tstats. What concerns me is that the newer zone has historically been pretty accurate, and thats the zone we noticed was significantly cooler than it was set to. Maybe these cheaper T3 Retail models just aren't going to cut it....


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## user_12345a (Nov 23, 2014)

Any professional honeywell should be good.

Maybe look at the focus pros if you don't want to spend a lot.

Not familiar with the newer T4/5/6 lines but they should be good too.

T6 manual shows compressor cycle rate under option 365


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## u3b3rg33k (Jul 17, 2018)

jdlevy said:


> Beats me. I'll definitely look into it further -- thanks again for walking me through that.
> 
> Regardless... I'm home today, have both units set to 75F, both zones are hovering right around that temp (a little cooler, but not as low as it had dropped yesterday), and the compressor keeps kicking on and off. Outside temp is a balmy 85F (Atlanta, GA).
> 
> ...


what matters here is how long it stays off for. under 3 minutes isn't good, over 5 minutes is fine.


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## jdlevy (Aug 20, 2018)

u3b3rg33k said:


> what matters here is how long it stays off for. under 3 minutes isn't good, over 5 minutes is fine.


Thanks. For the most part, it'll be around or over 5 minutes. The trouble there is the two zone system -- one zone finishes up, and then the other zone calls shortly thereafter. My understanding is that's just an issue I'll have to deal with. I've noticed it happens because the return vents are always open -- so when (for example) Zone 1 is cooling, but Zone 2 is not, Zone 2 is losing some of its cool air to the return, but not replacing it with cool air from the vent.


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## jdlevy (Aug 20, 2018)

jdlevy said:


> The trouble there is the two zone system -- one zone finishes up, and then the other zone calls shortly thereafter.


A perfect example: Zone 1 shut down -- whole system shut down -- two minutes later, Zone 2 called.


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## user_12345a (Nov 23, 2014)

The thermostats have a 5 minute delay to protect the compressor.

It may be worth seeing if the zone panel can be programmed to have a delay. There are also delay on break timers that can be added directly to protect the compressor.


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## beenthere (Oct 11, 2008)

jdlevy said:


> Thanks. For the most part, it'll be around or over 5 minutes. The trouble there is the two zone system -- one zone finishes up, and then the other zone calls shortly thereafter. My understanding is that's just an issue I'll have to deal with. I've noticed it happens because the return vents are always open -- so when (for example) Zone 1 is cooling, but Zone 2 is not, Zone 2 is losing some of its cool air to the return, but not replacing it with cool air from the vent.



Not quite how it works. 



Easy fix is you set the zone damper of both zones to a min open of say 10%. Then a small amount of air goes to the zone not calling, and prevents it from calling 2 minutes after the other one stops.


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## jdlevy (Aug 20, 2018)

I’ll definirely look into both the recommendations — 10% open damper and also the HZ311 settings to see if maybe there’s a delay I can activate.

I’ve been reading up more on the Ecobee and am hearing great things, especially by comparison to the Nest.


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## u3b3rg33k (Jul 17, 2018)

if you're going to shop around for fancy thermostats, don't forget the Honeywell Prestige system.


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## supers05 (May 23, 2015)

I have the ecobee3 and love it. My only problem with it, is that they aren't expanding its potential in the way I'd like. 

The sensi is a battery powered, basic wifi stat. Nothing special, but you can control it from your phone. 

Cheers!


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## jdlevy (Aug 20, 2018)

Hey all

Thanks to everyone again for the insight. To refresh the conversation: I've purchased two HW T6 Pro units (non-wifi), hoping that the extra flexibility in the options (differential temp and cycles per hour) will help.

Finally got my hands on the Furnace model: Its a Daikin DM80SS; 80,000 BTU/HR.


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