C4 Thermostat not Accurate

[Miman]

New to the C4 and just getting set up. Installed the thermostat, however seem to be having issues with it turning on and off at a set temperate. For instance, if I set the temperature for 74 degrees even after it hits 73 degrees, it doesn't turn off. It will run for a while and doesn't seem to turn off until until it hits 72. Any advice anyone can give?

[dannyboy]

In composer you will find an off set value you need to adjust to zero for the Tstat properties.

Don't know why it's not 0 by default?

[TexasBill]

You can actually set your thermostat so that it is accurate with a known thermometer.

Then you can say how many degrees you want after it reaches its desired temperature before shutting off. You will want to do this in Composer.

[dgbrown]

You have control over 3 basic items:

1) the calibration, a -/+ value to dial in the tstat based on known reference temp.

2) how far past the set point to cool or heat to

3) how far under the set point the temp needs to go before the hvac kicks back in

These three settings determine the operation of your stat.

[Miman]

Thanks so much.

[turls]

What about all the other advanced settings? Any general guidance on those? My HVAC guy punted on adjusting those. I don't trust any defaults since I have Geo...

[TexasBill]

What about all the other advanced settings? Any general guidance on those? My HVAC guy punted on adjusting those. I don't trust any defaults since I have Geo...

Enclosing a picture of what I have the "other" settings on mine set to. Let me know if you ahve questions.

Bill

[CFUG]

New to the C4 and just getting set up. Installed the thermostat, however seem to be having issues with it turning on and off at a set temperate. For instance, if I set the temperature for 74 degrees even after it hits 73 degrees, it doesn't turn off. It will run for a while and doesn't seem to turn off until until it hits 72. Any advice anyone can give?

Yes, this is somewhat typical and dependent on individual settings. Settings are specific to your install/living space/comfort level. My recommendation to you, since I'm not there to measure flow and temperature, is to set the max runtime to a lower number. This rec. is mainly due to the fact that you cannot set a 0~0.5 degF deadband and, to a lesser extent, your systems could be slightly oversized.

[turls]

What about all the other advanced settings? Any general guidance on those? My HVAC guy punted on adjusting those. I don't trust any defaults since I have Geo...

Enclosing a picture of what I have the "other" settings on mine set to. Let me know if you ahve questions.

Bill

Thanks Bill, the main thing still confusing me is the difference between the "auxiliary heat"/"emergency heat" sections and the bottom "auxiliary stage" section. I don't know for sure which of these boxes are getting used and ignored on my Geo unit (although it is called "emergency heat"). And even if I did know I wouldn't be sure what these should be set to.

If I'm not too far off, I think most settings in your picture are basically the defaults.

[thegreatheed]

In composer you will find an off set value you need to adjust to zero for the Tstat properties.

Don't know why it's not 0 by default?

Because it's more efficient to run many HVAC systems in fewer longer sessions, than more shorter sessions.

[TexasBill]

What about all the other advanced settings? Any general guidance on those? My HVAC guy punted on adjusting those. I don't trust any defaults since I have Geo...

Enclosing a picture of what I have the "other" settings on mine set to. Let me know if you ahve questions.

Bill

Thanks Bill' date=' the main thing still confusing me is the difference between the "auxiliary heat"/"emergency heat" sections and the bottom "auxiliary stage" section. I don't know for sure which of these boxes are getting used and ignored on my Geo unit (although it is called "emergency heat"). And even if I did know I wouldn't be sure what these should be set to.

If I'm not too far off, I think most settings in your picture are basically the defaults.[/quote']

The emergency heat or AUX heat is the electric heat that comes on when your heat pump or geo pump cannot keep the temperature up. How many degrees do you want it to fall below your set point before it "asks" for electric heat. There are several strips on most systems so you need to tell it when to being on stage 1 and then stage 2.

In a sophisticated HVAC system I don't believe that you need the thermostat doing much other than calling for heat or air. The unit does most of the work and kicks on things automatically from what I was told.

However - if you find out differently, I am willing to learn - so please share what you find out.

Bill

[turls]

Bill, according to the docs, according to your picture your aux will be kicking in when temp drops 2 deg. below set point. That seems awful quick on a Geo system, but I could be wrong. On a Geo system, you should be hooked up to take advantage of the C4 thermostat options.

I think after reading the docs posted in another thread I have a better understanding:

http://www.control4.com/files/dealers/documentation/21-0170_RevC_Thermostat_IG_Online.pdf

[TexasBill]

Bill, according to the docs, according to your picture your aux will be kicking in when temp drops 2 deg. below set point. That seems awful quick on a Geo system, but I could be wrong. On a Geo system, you should be hooked up to take advantage of the C4 thermostat options.

I think after reading the docs posted in another thread I have a better understanding:

http://www.control4.com/files/dealers/documentation/21-0170_RevC_Thermostat_IG_Online.pdf

First of all remember that this is not what I do for a living.

It appears to me that the following would be true -

If it is cold - very cold - your heat pump would struggle mightily to warm up your house. and when it is successful it will move the thermostat up. As it gets colder the response time for your house to respond would get longer and longer. Eventually you would get to equilibrium where your heat pump would simply continue to run - I would HOPE that at equilibrium - let's say that this is 10 degrees F your house would run forever - this is not good - I would HOPE that after running constantly for "x" amount of time the heat strips /assist would kick in based on time.

NOW - let's talk about how many degrees you want the house to "fall" in temperature before rescue comes in - PERSONALLY, I don't like huge fluctuations in temperature and particularly when I have my house in the winter set to 68 degrees 66 is pretty darn cold.

So - I think that your house when it is 0 degrees outside (gong with my 10 degrees paradigm) simply cannot sustain and hold your set temperature, consequently it will drop much slower than normal since it is actually TRYING to keep it at your set temperature. I think that opening that up a lot might mean that you stress your heat pump more than you want.

OK - I have no science or math here to back up my supposition, but I would personally need someone with a lot of experience to tell me that I should not do it this way for the above reasoning.

Anyone that can throw rocks at that logic?

Bill

[turls]

I think the idea with Geo according to my HVAC guy and what I have read is to not let the temperature change much especially during winter. If you keep stage 1 and stage 2 going so you don't get any huge drops past your set point then you never would use your heat strips, which are the real expensive options. I will have to watch this winter since I have everything setup now the way I want I think and my house has been completely remodeled to hopefully hold heat better (it wasn't horrible before).

I don't know about stressing heat pumps, my HVAC guy is not too worried about it, but I would like to hear other theories.

I know some people turn off the breaker to avoid using the heat strip aux power, but with the right settings on C4 I can avoid that so I only use them if absolutely necessary.

[TexasBill]

I think the idea with Geo according to my HVAC guy and what I have read is to not let the temperature change much especially during winter. If you keep stage 1 and stage 2 going so you don't get any huge drops past your set point then you never would use your heat strips, which are the real expensive options. I will have to watch this winter since I have everything setup now the way I want I think and my house has been completely remodeled to hopefully hold heat better (it wasn't horrible before).

I don't know about stressing heat pumps, my HVAC guy is not too worried about it, but I would like to hear other theories.

I know some people turn off the breaker to avoid using the heat strip aux power, but with the right settings on C4 I can avoid that so I only use them if absolutely necessary.

I have foam insulation and live in Texas - so I was interested to see what would happen last winter (my first in the house.) We had 50-80 dollar electric bills. The heat almost never ran at all. We have a propane fireplace mostly for looks. We had a party and had to open the doors to the outside because the house was too hot. We cannot run the fireplace for more than about an hour or the house overheats. (we could turn on the air conditioning but that seems rather dumb in January.)

Bill