Other Talk "Otterville" plus Religion/Politics

Heating & Air Question

Old 03-11-08, 06:34 AM
  #1  
Needs to Contact Admin about multiple accounts
Thread Starter
 
Join Date: Jun 2004
Location: Winston Salem, NC
Posts: 2,806
Heating & Air Question

We have a Trane AC unit outside the house and I'm not sure if there's a problem with it or not, and thought you guys might be able give me some insight.

My wife feels the cold more than me, so always has the thermastat set at like 70 in the house. When it warms up to that it will automatically shut off. But on occassions when the temperature in the house drops slightly the heat will kick on, but will only blow out cool air. It's not until I turn the heat up on the thermastat and the emergency heat kicks on does it start blowing hot air.

Then once it warms up, I turn the heat down a little and it goes back to normal.

Could it be I need to add some freeon? (sp?)
DVDMagic is offline  
Old 03-11-08, 06:54 AM
  #2  
DVD Talk Legend
 
Join Date: Jun 1999
Location: USA
Posts: 12,209
Sounds like the normal workings of a heat pump.
Brian Shannon is offline  
Old 03-11-08, 09:26 AM
  #3  
DVD Talk Special Edition
 
Join Date: Nov 2000
Location: Northern VA
Posts: 1,445
When the "Emergency" heat kicks on, your bascially turning power on to a calrod (if you don't know, it's like the burner on an electric range that turns red). You pouring pure electricity into a rod with resistance and it's heating up. Then your blowing air across it and pumping it into the house. That is why it's very warm.

The heat pump is probably putting out warm air ok, it's just not as hot as the auxillary mode puts out. Many people don't like forced air because it feels cold to them. It could be 90 degree air, but because it's blowing, it feels cold on them.

How old is your heat pump? I see your in NC, has it been really cold down there?

When you get to a certain temperature heat pumps really loose their effectiveness and that is what the emergency heat is for. This is why those who live in New England and the Northern states all have oil and gas furnaces.


If your heat pump is old, it might be getting a little tired. If the house or heat pump is new, the builder may have put the bare minimum size in for the house.


Other things that can help are the installation of a bigger heat pump, the installation of a humidifier (in duct), the installation of automatic dampers so you can have more than one zone and it will put the heat in the area you need it without heating the whole house.


As a fix for now, you might look at "balancing the house" and closing off vents to hotter rooms or rooms you don't use to heat the parts of the house you do need heat or use. Often there is a manual damper near your air handler in the basement or attic that lets you accomplish the same thing, but for an entire floor or side of your house. (In winter, you close off the upper floor, heat the bottom and the heat rises, in summer, you open it up and the cool air comes out on the second floor and settles to the first)


Not many answers, but some info. Hope it helps.
Jeeden is offline  
Old 03-11-08, 10:32 AM
  #4  
DVD Talk God
 
kvrdave's Avatar
 
Join Date: Aug 1999
Location: Pacific NW
Posts: 86,200
Is this a heat pump? From what you describe, it is. The air coming out may feel cold, but it is probably still warmer than the air in the house. Heat pumps gradually warm.

Just call the furnace guy if you are really unsure. Not a bad idea to have them serviced on occasion., anyway.

Clean the filters?
kvrdave is offline  
Old 03-11-08, 05:17 PM
  #5  
DVD Talk Limited Edition
 
Join Date: Jun 2000
Location: BV VA
Posts: 6,061
Or don't do what I did. Download the manual to the thermostat and make sure it's setup correctly. When I put my new one up I turned the A/C on and the heat cut on. Sure it sounds silly, but it's possible
kantonburg is offline  
Old 03-12-08, 05:51 AM
  #6  
Needs to Contact Admin about multiple accounts
Thread Starter
 
Join Date: Jun 2004
Location: Winston Salem, NC
Posts: 2,806
Thanks for the help and insight guys. Judging by that, I'm pretty sure that everything is running just fine. It's actually my wife who thinks there's something wrong, but then she tends to feel the cold more so likes it really warm in the house, much to my dismay.

I believe the unit is no more than 10 years old and we actually had it serviced last year when the same problem arose. We couldn't figure out why the emergency heat kicked on.

Anyway, appreciate the info.
DVDMagic is offline  
Old 03-12-08, 09:11 AM
  #7  
DVD Talk Special Edition
 
Join Date: Nov 2000
Location: Northern VA
Posts: 1,445
Originally Posted by DVDMagic
Thanks for the help and insight guys. Judging by that, I'm pretty sure that everything is running just fine. It's actually my wife who thinks there's something wrong, but then she tends to feel the cold more so likes it really warm in the house, much to my dismay.

I believe the unit is no more than 10 years old and we actually had it serviced last year when the same problem arose. We couldn't figure out why the emergency heat kicked on.

Anyway, appreciate the info.

Yea, Emergency is kinda misleading. A lot of thermostats now say "auxillary" heat.
Jeeden is offline  
Old 03-12-08, 12:46 PM
  #8  
DVD Talk Legend
 
Dr Mabuse's Avatar
 
Join Date: Jun 2007
Location: 75 clicks above the Do Lung bridge...
Posts: 18,950
Originally Posted by DVDMagic
We have a Trane AC unit outside the house and I'm not sure if there's a problem with it or not, and thought you guys might be able give me some insight.

My wife feels the cold more than me, so always has the thermastat set at like 70 in the house. When it warms up to that it will automatically shut off. But on occassions when the temperature in the house drops slightly the heat will kick on, but will only blow out cool air. It's not until I turn the heat up on the thermastat and the emergency heat kicks on does it start blowing hot air.

Then once it warms up, I turn the heat down a little and it goes back to normal.

Could it be I need to add some freeon? (sp?)
there is a part in a central heat and air unit... that resets everything, and triggers everything, on the signal of the thermostat... basically a circuit switch... usually called a 'fan relay switch' or 'fan control switch' - IIRC... a small unit... most of them made by a company called 'Therm-O-Disc'...

it will 'stick'... and heat or AC will not be triggered to come on by the thermostat... often a reset of the thermostat, turning it off and then back on, etc. will trigger one that is failing to 'unstick' and activate the circuit... as the application of voltage finally 'flips' the switch on... when they go completely the unit no longer responds to the thermostat for normal operation...

it's a common thing and not too expensive to replace... call a good HVAC repair company and they can fix it... it's one of the more common issues...

since Trane is the best in the business right now it will be a little more for the part... i have a 4.5 ton Trane, and a 3 ton Trane on my house... they rock...

that's most likely the issue based on what you describe... assuming the thermostat is sound, of course, and unless you have actually lost the compressor...

Last edited by Dr Mabuse; 03-12-08 at 12:49 PM.
Dr Mabuse is offline  
Old 03-13-08, 07:13 AM
  #9  
Needs to Contact Admin about multiple accounts
Thread Starter
 
Join Date: Jun 2004
Location: Winston Salem, NC
Posts: 2,806
Originally Posted by Dr Mabuse
there is a part in a central heat and air unit... that resets everything, and triggers everything, on the signal of the thermostat... basically a circuit switch... usually called a 'fan relay switch' or 'fan control switch' - IIRC... a small unit... most of them made by a company called 'Therm-O-Disc'...

it will 'stick'... and heat or AC will not be triggered to come on by the thermostat... often a reset of the thermostat, turning it off and then back on, etc. will trigger one that is failing to 'unstick' and activate the circuit... as the application of voltage finally 'flips' the switch on... when they go completely the unit no longer responds to the thermostat for normal operation...

it's a common thing and not too expensive to replace... call a good HVAC repair company and they can fix it... it's one of the more common issues...

since Trane is the best in the business right now it will be a little more for the part... i have a 4.5 ton Trane, and a 3 ton Trane on my house... they rock...

that's most likely the issue based on what you describe... assuming the thermostat is sound, of course, and unless you have actually lost the compressor...
That actually does sound close to what the problem could be. I'm going to keep an eye on the situation and see if it arises again. The weather is starting to get nicer now, so there really shouldn't be much need for the heat at all.

We'll see what happens in the summer when it's time to run the AC most of the time
DVDMagic is offline  

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 On
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.