Can I disable emergency heat on my Geo?

[hilldweller]

I have a 5 ton Climatemaster Tranquility 27 hooked to a Honeywell VisionPro TH8000 (TH8320U) thermostat that heats and holds my house temp just fine. If I use the programmable features and lower my temp at night, can I prevent the EM heat frin coming on in the morning? I don't mind waiting on the longer recovery time of the geo. I just hate sending more to the utility company than I have to. Would changing to system type in the thermostat to 2 heat/2cool heat pump (no aux. heat) trick it into leaving my EM heat off? I don't have the remote outside temp. Thanks!

[DAVE W]

we install a toggle switch on the side of the climatemaster unit to disable the backup heat install between the W1 on the unit and aux. wire from the thermostat leave off to disable back up heat.

[junkhound]

See you are in PA, so you may need emergency heat when it is -40 F(or C); otherwise, I'd advise you to have your tech disconnect it!.

Seldom gets below 20F here, my own emergency heat is disconnected. You may have a separate circuit breaker for your emergency heat. I'd turn it off until it gets to near zero F if you have GSHP or WSHP, or unless you are in an uninsulated house.

[drsmith012]

The breaker for my strip heat also power the blower and electronics. I have been thinkin of the switch Idea. I would think that the Tranquility 27 is advanced enough, like my envision, that if a compressor lockout condition occurs it will activate the strip heat regardless of the state of the W input. My W wire is disconnected also.

[bullmoose]

If you have the Vision Pro 8000 I would recommend having the outdoor temperature sensor installed and set to lock out the emergency heat until it reaches a certain outdoor temperature. Seems to be the easiest way to control it. Unless you don't mind turning a switch on and off whenever you do need it. Those sensors are accurate too, as long as it doesn't get direct sunlight or wind blowing on it. I look at my stat every morning before work to determine how many clothes to put on. Just my two cents, but I don't have a geothermal system either. Although I wish I did, but I just don't have the land to do it. Good luck with your system.

[madhat]

I rewired my Air to Air so the Strip heat won't come on, even in defrost, till the basement drops to 55 F or the outside air drops to 10 F. Used a couple salvaged remote sensor stats. If emergency heat is switched at the stat, the strip heat will work normally. Wouldn't recommend a toggle switch, lets say you are on vacation and something happens. Wouldn't want to come back to burst pipes, flooded house.

[hilldweller]

Thanks for all the helpful replies. Just the info I needed. I wish all of you a great new year!

[drsmith012]

Just found out my waterfurnace has a dip switch to disable aux strip heat. According to the manual full "emergency heat" is still available when "aux" heat is disabled.

the other option is not to use set backs at night. I tried set backs one January and none the next Feburary. January had less heating degree days than Feb but my Feb bill was siginificantly lower than my Jan bill. If your heatpump can maintain temp at low stage then it is better to let it run continously on low instead of using full capacity and possibly strip heat to recover in the morning.

The Flordia energy commision (or council) actually recomends not using set backs on a heat pump system as it does not save but rather waste energy.

[JoeGen]

I've been told/read that aux heat shouldn't really come on unless there is at least a 4 degree difference between current temp and set temp, is that true?

I do a one degree step down at night (from 69 to 68) and I keep waking up to Aux Heat being on. The current temp and the set temp are both at 69 but Aux Heat is running.

If I turn the thermostat to OFF, then back to heat, it seems like the system resets and its 69/69 and off. Temp drops a bit and then regular geo heat comes on, system working normally at that point.

Any tips on what could be the issue? The thermostat? thermistors? My HVAC guy is stumped and by the time he gets over here, system is running normally.

The system is a ClimateMaster Tranqulity 27 2 stage earthpure 3 ton model TTVO38AGC01ALKS. It shares the loop field with a split unit 2 ton for upstairs, TTS026AGC00CNNS.

[Bergy]

What make and model number is your t-stat?

Bergy

[JoeGen]

Its a Honeywell VisionPro TH8000 series, model TH8320U1008.

[Bergy]

JoeGen,

Honeywell's stat is a bit of as mystery, no one seems to know exactly how it's logic works for 1 st, 2nd and 3rd stage heat. We have seen many of them running aux heat while the set point and room temp is the SAME. After many "chats" with Honeywell and Enertech, our heat pump mfg., the following thermostat settings seem to work the best.

#160 schedule options... Set this to "0" nonprogrammable

#220 1st stage compressor... Set this to "1" CPH

#230 2nd stage compressor... Set this to "1" CPH

#260 Aux heat... Set this to "9" CPH

#270 Emergency heat... Set this to "9" CPH

#680 Temperature control in heat... Set this to "1" Least aggressive
The least aggressive setting will allow the heat pump to run longer before aux heat is engaged.

If you are not comfortable making these changes, have your installer reprogram the stat.

Bergy

[beenthere]

You won't like that 9 setting on the aux or emergency heat.

[wagnerhvac]

You could get your contractor to put on the climatemaster tstat with programmable set backs. The new tstat has a logarithm feature that will monitor the increase in temp and time periods which ultimately means the stat is smart and wont bring the back up on

But I do have a question to ponder. You are saving money already why dont you keep your comfort level and dont set back your temp? just ponder I dont need an answer

[JoeGen]

It is a comfort thing for me, I actually like it to be about 2 degrees cooler at night when I am in bed with my big comforter on. Yes, I know, a little TMI. I know I lose a little efficiency, but I am losing more than I should with the aux heat coming on with only a one degree difference (switched to 1 degree from two a while ago to do some testing).

This morning, it was saying 68/68 (inside/set to) with Aux Heat On for a while, so I set it down one degree and it said 68/67 and the Heat stayed on. Shouldn't that have registered as a met condition? Took 10 min for it to show 67/67 with Heat still on the whole time (not Aux). Interestingly enough the digital thermometer I placed right next to the t-stat showed 68.4 before, during and after the inside 1 degree t-stat drop.

I think tonight I am going to take off the drop and just keep it at 68 all night and see what happens in the morning.

Are the residential ClimateMaster t-stats available directly to homeowners? Is the general consensus that they are good units?

[Bergy]

You won't like that 9 setting on the aux or emergency heat.

Why is that?

Every since we started using the Honeywell stats, Aux heat has been a problem. I did a lot of complaining to Honeywell and got NOWHERE. When Enertech Mfg.(GeoComfort and Hydron Module) got involved with Honeywell and began to use their stats, I started pestering them about it. You know what rolls down hill... Enertech and Honeywell got together on the problem and came back with the posted recommendations.

Bergy

[JoeGen]

You won't like that 9 setting on the aux or emergency heat.
Why is that?

Yes, would be good to get some info on why you think the 9 is not an optimal setting. Thanks!

Actually, I just pulled (not changed) my settings on my t-stat and here are my results:
120: 20
130: 10
140: 1
150: 5
160: 4
170: 12
190: 0
200: 0
220: 3
230: 3
260: 9
270: 9
280: 0
300: 0
320: 0
330: 1
340: 0
500: 0
510: 0
520: 0
530: 1
540: 1
580: 5
600: 90
610: 50
640: 12
650: 0
660: 0
670: 0
680: 2
690: 2
700: 0
710: 0

I was already at 9 for 260 and 270. 160, 220 and 230 are different than recommended though.

[beenthere]

3.25 min on, 3.35 min off, 3.25 min on, 3.35 min off, 3.25 min on, 3.35 min off, 3.25 min on, 3.35 min off, 3.25 min on, 3.35 min off, 3.25 min on, 3.35 min off, 3.25 min on, 3.35 min off, 3.25 min on, 3.35 min off, 3.25 min on, 3.35 min off.

In emergency heat, you hear it cycling on and off along with the blower if you don't run your blower 24/7.
If you have a VS blower and run it 24/7 you will probably notice the blower going to a higher speed and then back down to a low speed all the time.
Becomes very annoying.

In aux heat. If your HP isn't keeping up, and is discharging 85° air. You'll get 100°(10KW at 2000CFM) for 3.25 minutes and then back down to 85° air for 3.25 minutes.
9 times an hour.

Not very comfortable.

[Bergy]

What? While I'm no expert on CPH I do know that as long as there is a call for strip heat, the unit runs. I have NEVER heard, or seen, a unit that runs 3 off 3 during a single call for heat.

Bergy

[beenthere]

Go to a unit with the emergency heat set to 3 CPH. Set the stat to emergency heat. If its near the equipments 50% load range. It will cycle as I said.

Seen it several times on units set to 9 CPH.

[JoeGen]

So last night, I did no step down in the heat. Was checking it until about 11pm last night and it was always just 68/68 with "Heat On", no Aux. Woke up this morning about 6:30am and checked, "Heat On", no Aux. Climb back into bed to get a few more winks before I had to get up, and I hear the Aux come on. Go to the t-stat and sure enough it says "Heat On Aux", t-stat is showing 68/68.

I climb into bed and listen, and I hear the Aux going on and off alternately. Quick looks at the clock seem to comfirm BeenThere's post, it was about every 3 minutes for several cycles.

To be sure, I go in to time them with a stopwatch, but I did not get a pure 3 on 3 off cycle. Aux Heat seem to be on for about 3 min usually, but it was longer between off cycles. It seemed more random than anything (just did a 12 min off cycle then a 1:45 min on cycle). I will take better measurements tomorrow when I have more time in the morning to just stand in front of my t-stat.

Remember, I haven't changed any settings on the t-stat yet, they are all as listed in the post below. Not liking that aux heat is coming on when the t-stat constantly shows 68/68.

Thoughts?

[phabighorst]

Why is that?

Every since we started using the Honeywell stats, Aux heat has been a problem. I did a lot of complaining to Honeywell and got NOWHERE. When Enertech Mfg.(GeoComfort and Hydron Module) got involved with Honeywell and began to use their stats, I started pestering them about it. You know what rolls down hill... Enertech and Honeywell got together on the problem and came back with the posted recommendations.

Bergy

Stating in 2010 you will see Enertech moving to "Big Blue" Thermostat they will still have the Honeywell Stat. In the new 2010 price book you will see, White-rodgers "Big Blue" ATGNE32A works very well I have one in my house and I like it. ask your TM about it.

[Bergy]

We got the information about that at last years dealer meeting. I've never been impressed with the Honeywell stat used for Geo. They are VERY slow to respond to market needs so it appears as if White Rodgers is stepping up to the plate. As I posted before, Enertech and Honeywell can up with the recommended stat settings. We set them up that way and have not had the complaints about too much run time on aux heat .

Bergy

[beenthere]

The CPH is only accurate at 50% load.
Since you were having a long off cycle. You weren't at 50% of your equipments load(heat pump plus aux ability).

Changing to a lower CPH for aux heat probably would have either satisfied the stats call for heat. Or got it to go to fist stage heat pumps.

If you switched to emergency heat. it would have had shorter off cycles.

[JoeGen]

So what would be the best value then for 260 and 270? Would changing 220 and 230 from 3 to 1 by itself make a difference? Or setting 680 down a step to 2 or 1? What should be the order of things I change to test or should I do them all at once?

The settings that were suggested were:

#160 schedule options... Set this to "0" nonprogrammable

#220 1st stage compressor... Set this to "1" CPH

#230 2nd stage compressor... Set this to "1" CPH

#260 Aux heat... Set this to "9" CPH

#270 Emergency heat... Set this to "9" CPH

#680 Temperature control in heat... Set this to "1" Least aggressive
The least aggressive setting will allow the heat pump to run longer before aux heat is engaged.

[beenthere]

So what would be the best value then for 260 and 270? Would changing 220 and 230 from 3 to 1 by itself make a difference? Or setting 680 down a step to 2 or 1? What should be the order of things I change to test or should I do them all at once?

The settings that were suggested were:

#160 schedule options... Set this to "0" nonprogrammable 0

#220 1st stage compressor... Set this to "1" CPH 3

#230 2nd stage compressor... Set this to "1" CPH 2

#260 Aux heat... Set this to "9" CPH 3

#270 Emergency heat... Set this to "9" CPH 3

#680 Temperature control in heat... Set this to "1" Least aggressive
The least aggressive setting will allow the heat pump to run longer before aux heat is engaged.

1 Is fine for aggression setting.

[luv2cruiserccl]

i WOULD "NOT" use a toggle switch. Get a Thermostate with out door sensor and you get the temp outside when you want it to come on, and there are some that are custom that the unit has to run so long no matter what the temp is before the aux heat comes ok. Never turn something off or unplug this or that just do it right and never have to work about it again.

[drsmith012]

CPH is a variable in the PID loop equation (aka transfer equation) that resides in the stat memory. A PID equation is an equation that looks at the set point, how far from the setpoint you are, how fast you are moving toward or away from the set point and what is the state of the system trying to keep the set point, in this case what stage the system is at. The CPH adjust the agressiveness of the stat. But on these stats CPH doesn't really seem to do too much to increase of decrease the hysteresis at lease three engineers at (I was one of them) could not get this programed to the owners liking. He now has a blue one.

I have the White-rodgers (Emerson). My coworker and a couple of others have gone to this as well and I have installed on in my parents house. Instead of having to select something most people don't understand like CPH the WR stat lets you set the hysteresis (temperature swing). manual here (http://www.white-rodgers.com/wrdhom/pdfs/instruction_sheets/0037-6753.pdf) I have mine set to the maximum energy saving which is max discomfort but I really don't notice any temp swings.

[JoeGen]

I'm going to try one of the recommendations:

#160 schedule options... is it safe to leave this as programmable if I have no set backs scheduled? Will having these as 1 and using a 1 or 2 degree set back at night and the below settings be incompatible? I currently have this set to 1 still but have no setbacks scheduled, its 68 24/7.

#220 1st stage compressor... Set this to "3" CPH

#230 2nd stage compressor... Set this to "2" CPH

#260 Aux heat... Set this to "3" CPH

#270 Emergency heat... Set this to "3" CPH

Will let you know how it responds...

[beenthere]

Using a set back and electric resistance heat. often doesn't save any money.

With Adaptive recovery enabled. the stat will attempt to recover without using the more expensive resistance heat. It may or may not use it though.

[JoeGen]

I as under the impression my tstat supported adaptive recovery, but just not understanding what would cause aux heat to come on when internal temp is 68 and set to temp is 68... thought the geo would be able to handle a degree or two difference also.

[beenthere]

You asked about using a 2 degree set back.
Thats when it may or may not use aux.