Thermostat for use with heat pump & em. heat

Reply

  #1  
Old 02-02-08, 04:12 PM
H
Member
Thread Starter
Join Date: Feb 2008
Posts: 16
Received 0 Votes on 0 Posts
Thermostat for use with heat pump & em. heat

Hey,

I'm looking at replacing my current Honeywell basic on/off thermostat, and I'm looking at going with a new Honeywell programmable one, specifically the TH8500 touch-screen one. But I need a little information first.

I have electric emergency heat, which I try to never use if at all possible, but I hear these thermostats will turn on the emergency heat if you try and increase the temperature by more than a few degrees at a time. Is there any way to disable this on these thermostats, but still be able to manually turn on the emergency heat on really cold days? I only want it to use the heat pump for everyday use.

Thanks!
 
Sponsored Links
  #2  
Old 02-02-08, 04:50 PM
Jarredsdad's Avatar
Member
Join Date: Oct 2002
Location: Troy, VA
Posts: 1,532
Received 0 Votes on 0 Posts
I hate to burst your bubble, but you can't get away from it.

First, Aux heat and EM heat is exactly the same thing. Both modes turn on electric strip heat.

Two different names for the same thing?

When the temp setting is a degre or two from the actual room temp the heat pump turns on. If it's 3 or 4 (or more) different the Aux heat comes on to help the heat pump. Aux heat also comes on when ever the heat pump goes into defrost mode.

Em heat is only used (needed) when the heat pump is broke and you need heat. Still the same electric heat but called a different name.

I thinck Robert Shaw still makes stats that bring on Aux heat over time rather than temp but not in touch screen.

Change the stat set the temp and let it go.
 
  #3  
Old 02-02-08, 05:14 PM
H
Member
Thread Starter
Join Date: Feb 2008
Posts: 16
Received 0 Votes on 0 Posts
Damn, that's what I was afraid of. Does Honeywell (or any other products you'll find in store) make anything that won't automatically turn on the emergency/aux heat? Doesn't have to be touch screen. Don't they realize that's a wickedly expensive way to heat your house, and some people don't want to use it unless they really have to?


Anyway, thanks for the answer!
 
  #4  
Old 02-02-08, 06:37 PM
Jay11J's Avatar
Member
Join Date: Sep 2001
Location: Rochester, Minnesota
Posts: 18,427
Received 0 Votes on 0 Posts
You can use the Honeywell IAQ t-stat with an outdoor sensor added to it, With the outdoor sensor, you can "Lock" out the electric heat.

Why change of temp? Heat pump are best to "Set it and forget it".
 
  #5  
Old 02-02-08, 06:42 PM
H
Member
Thread Starter
Join Date: Feb 2008
Posts: 16
Received 0 Votes on 0 Posts
Nobody's home during the day, and we're all asleep at night, so it's a waste of electricity to have them running at those times.

Anyway, thanks for the suggestions and information guys!
 
  #6  
Old 02-02-08, 08:42 PM
Jay11J's Avatar
Member
Join Date: Sep 2001
Location: Rochester, Minnesota
Posts: 18,427
Received 0 Votes on 0 Posts
There been a couple of guys reporting that the electric bill is cheaper when the just set it and forget it.

Heat pump can't recover quick enough like a gas furnace, so it's going to have to work harder to recover and depends on t-stat, the electric heat is kicking in to help catch up.
 
  #7  
Old 02-03-08, 08:15 AM
Jarredsdad's Avatar
Member
Join Date: Oct 2002
Location: Troy, VA
Posts: 1,532
Received 0 Votes on 0 Posts
Cheaper just to leave it

Think of it this way. Say your stat has a 2 degree deadband and the stat is set for 70 degrees. When the temp gets down to 68 the heatpump comes on until it's 70 again. Keeps doing that in regular cycle.

If you set the temp back to say 65 while at work it's still going to do the same thing as before just with different temps. Since the heat loss in your house isn't going to change the cycle rate of the pump will be about the same.

If you set the stat to bring the temp back to 70 a half hour before you get home from work it's going to bring on the heatpump and strip heat to get from 65 up to 70 and run much longer to make up that 5 degrees.

So like Jay said just pick a temp, set it and forget it.

You may want to run the fan all the time to keep air moving. Or look into adding a humidifyer to help hold the heat in the air.
 
  #8  
Old 02-03-08, 08:48 AM
H
Member
Thread Starter
Join Date: Feb 2008
Posts: 16
Received 0 Votes on 0 Posts
Actually we turn it completely off during the day, the sunlight is enough to keep the house temperature from dropping too low. During the night we drop the temperature back by about 5 degrees, but it never gets cold enough in the house for the furnace to come on. I know because it wakes me if it ever does come on. Our house is heavily insulated.

Our current thermostat never turns on the auxiliary heat, except of course when the heat pump is defrosting or we hit the emergency heat switch on the thermostat.

Ah well, I think I'll just stick with my current thermostat. Those touch screen ones are nice looking, but a lot of flash for just a thermostat!
Thanks guys!
 
  #9  
Old 02-03-08, 11:03 AM
Ed Imeduc's Avatar
Member
Join Date: Aug 2002
Location: Mountain Williams Missouri
Posts: 18,389
Received 0 Votes on 0 Posts
Wink

Actually we turn it completely off during the day, the sunlight is enough to keep the house temperature from dropping too low. During the night we drop the temperature back by about 5 degrees, but it never gets cold enough in the house for the furnace to come on. I know because it wakes me if it ever does come on. Our house is heavily insulated.
Have you tried to see what the cost is to just set it and let it alone???? I sure cant hear when the electric elements come on in my heatpump. I can feel it is all.
 
  #10  
Old 02-03-08, 11:50 AM
H
Member
Thread Starter
Join Date: Feb 2008
Posts: 16
Received 0 Votes on 0 Posts
Never looked into the cost of having it run all day, but I can't see how having the fan in the furnace and the heat pump running can cost any less than not having them run at all :P

The heat pump is right outside my window, and the inside unit is right under me, so yeah, I hear it at night!
 
  #11  
Old 02-03-08, 01:43 PM
Jarredsdad's Avatar
Member
Join Date: Oct 2002
Location: Troy, VA
Posts: 1,532
Received 0 Votes on 0 Posts
Just a thought

Have you thought about a Climatouch tstat?

It's expensive, but since I worked for a distributor at the time I got it for 180 cost (no markup).

It tells me the outdoor temp (with an add on rf transmitter) and will control the humidifyer (when I get off my butt and install it).

The two best thinks it does for me is tracks actual fan run time for filter changes, AND I entered the total KW of the heatpump, fan, and electric heat along with the cost of electricity. All I need to do is check the "energy watch" menu and I get a close estimate of how much it costs me to run the system.

I say close because you cant enter exact KW's. I had to enter 1 KW for the fan even though it doesn't use that much energy.

I just went in and looked. Cost for the last 45 days is about $138.78 or about $3 a day.
 
  #12  
Old 02-04-08, 03:20 AM
G
Banned. Rule And/Or Policy Violation
Join Date: Oct 2007
Posts: 176
Received 0 Votes on 0 Posts
you can turn off the aux, heat by throwing the breaker for the heat strip, but the defrost mode can get a bit chilly. If your house looses little heat due to the sun and insulation then your heat strips should not be coming on.
 
  #13  
Old 02-06-08, 07:08 PM
S
Member
Join Date: Apr 2007
Location: Vagrant
Posts: 220
Received 0 Votes on 0 Posts
Those Vision pro IAQ honeywell 8000 t-stats like jay was talking about are perfect for what you want to do. All you need is the outdoor sensor accessory. You can set it (lock out the aux coils) so that the aux heat will not come on untill it gets to the temp outside where you would really need them to come on, that way only the heat pump will run. Plus it is lots of fun to play with the settings.
 
  #14  
Old 02-24-08, 04:47 PM
Z
Member
Join Date: Sep 2006
Location: Connecticut
Posts: 251
Received 0 Votes on 0 Posts
Ditto on the IAQ. If you want the ultimate amount of control and flexibility over your system this is your best choice.
 
  #15  
Old 05-21-08, 06:38 PM
L
Member
Join Date: May 2008
Posts: 1
Received 0 Votes on 0 Posts
Question carrier thermostat wires

I had to replace old stat with new digital can only get fan to blow how can I check system without stat with just wires
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: