Question about Air Conditioners

1 Answer

I BOUGHT TWO DIFFERENT PROGRAMMABLE THERMOSTATS TO INSTALL IN MY HEAT PUMP SYSTEM, I FOLLOWED THE DIRECTIONS TO A T BUT WHEN I SET IT TO COOL THE UNIT REVERSES AND PRODUCES HEAT WITH BOTH THERMOSTATS. MY EXISTING THERMOSTAT HAS TWO MERCURY BULBS AND WORKS FINE, i HAD TO PUT THE OLD ONE BACK IN. WHAT CAN THE PROBLEM BE?

Posted by on

1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    Hot-Shot:

    An expert who has answered 20 questions.

    Corporal:

    An expert that hasĀ over 10 points.

    Mayor:

    An expert whose answer gotĀ voted for 2 times.

  • Expert
  • 95 Answers

Heat pumps normally have what is called a jumper wire between you R and RC, RC run cooling. You may not have the jumper installed correctly. Instead of RC you may be using RH run heat

Posted on Aug 10, 2008

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Fan will not come on when it's set in auto mode


If your thermostat is being used with an electric heating system and the fan does not start in heating mode on auto; remove the thermostat from the subcase on the wall and check for a switch on the back of the thermostat. A lot of electronic thermostats have a switch on the back that says electric/heat pump and gas/oil. If you have electric heat or heat pump you need to switch it to this side. Usually this is set at the factory for gas/ oil. Gas/oil furnaces have built in means of bringing on the fan and electric/ heat pumps are brought on by the thermostat.

Feb 11, 2015 | Hunter Fan Company 42999B - Heat/Cool...

Tip

How to change a thermostat yourself


Choosing your new thermostat:
Firstly you have to ask yourself why you are changing your thermostat. Is your old thermostat simply broken? Are you wanting a simple upgrade from analog to digital? Are you looking to save on energy costs using a programmable? Are you attempting to integrate your central system into a smart home network? Whatever the reason your choice of thermostat should not be simply the cheapest on the shelf. Different system types may require different thermostat types.
Before purchasing your new thermostat you need to figure out what kind of system you have. The general idea is *H/*C, denoting the number of heating/cooling stages and options, and fuel type (heat pump, gas furnace, electric furnace, etc.). An example would be a typical heat pump- it has a single cooling stage and a dual heating stage (heat strips, compressor) making it a 2H/1C heat pump thermostat. I usually install the Honeywell FocusPro 5000/6000 series for non-programmable/programmable applications for it's ease of use and general reliability.

Before beginning the swap always make sure power is off to both the indoor and outdoor sections!

Determining which wires go where:
First off, you may not ever rely on wire colors to guide you to the proper terminal. We have standard practices for wire color to function, but this varies from region to region and sometimes if a wire shorts out a substitute in the bundle may be used. When removing the old thermostat physically writing down or labeling the wires is not an exercise in tedium- it is almost necessary and something which I do every single time. You will usually have these terminals on the new device:
Rc- Cooling Power (usually jumpered to R/Rh)
R/Rh- Heating Power (usually jumpered to Rc)
Y- Primary Compressor
C- Common
O/B- Reversing valve (activated in cooling/heating)(Heat pump)
W- Primary heat (Furnace or Electric heat)
G- Indoor Blower
E/Aux/W2/X2- Emergency/Secondary heat stage
Y2- Secondary Compressor (2 stage cooling)
L- Communicator for E-Heat (Heat pump)
If you do not have all of the terminals on the old as you have on the new it may not be the end of the world. Required terminals are an R, a Y (if AC is present), a W/W2/E/Aux/X2 (if heat is present), an O/B (if heat pump), and usually a G. Common is optional most of the time as it is used to power the thermostat only and batteries may be substituted. L is not commonly used. If you have any doubts as to which wires go where, stop now. Miswiring can destroy a system's low-voltage and potentially start a fire.

Replacement:
After labeling the old wires and removing the old thermostat, you must attach the new baseplate. Leveling the baseplate is not as important as it was with older mercury thermostats, but still applicable at least within +-5 degrees of rotation. If you are attaching the baseplate to drywall with no backing wood installing wall anchors (usually supplied) is key. Make sure you have a proper length of bare wire (not too long, not too short) before attaching to the terminals. Do not overtorque the screw lugs. Pull back on the wires after attaching them to ensure the connection is proper. It is a good idea to plug the hole through which the wires come with something (I use plumbers putty) to keep a draft from effecting the thermostats temperature. Many thermostats will require some pre-programming before hooking up (refer to installers guide)- I find this much easier to do via batteries before attaching the face to the baseplate. Once the face is on and the power returned to equipment, test the system. Keep in mind modern thermostats include a 3-5 minute delay for compressors as a protective layer.

Common Pitfalls:
Zone system wiring can be confusing and is not as standardized as it should be. If you have a zone system and plan to purchase new thermostats it is highly recommended to call in an experienced service technician.
High SEER and IQ drive systems use very different types of thermostats than conventional systems. For now the newer technology has yet to be perfected in the public market and these changeouts are best left to an experienced professional.
Some older thermostats use B as common (Trane Weathertron for example) This is not to be confused with B as a heating changeover valve and if it is can blow out a fuse,transformer, and/or your brand new thermostat upon startup.
Most face to baseplate interfaces are pin based- if one is not quite careful bending one of these pins during attachment can be irreparable.
Common is the least standard color across installers. Most use either brown or blue, but I've seen some use green and black, usually used for blower and secondary heat respectively. Never assume wire color as a standard.
Most of the service calls regarding thermostats I receive come from homeowners who have purchased and self installed incompatible thermostats. This is something I do everyday for a living, not so for the average homeowner. Take your time and do your research.
Save your manuals- all of them. Many cheap offbrands can be next to impossible to find manuals for online.
When in doubt, call in a pro. Most of us charge around $70-100 to install a thermostat (plus cost). This is almost always much cheaper than a service call to diagnose and repair a low voltage problem.

on Sep 25, 2011 | Air Conditioners

1 Answer

Why does lenox heat pump not heat in normal heat mode?


The thermostat is not a heat pump thermostat or it is not wired or set up correctly.

Feb 05, 2015 | Air Conditioners

1 Answer

My furnace wont turn on.changed batteries but still doesnt turn on! there doesnt seem to be "option" for "HEAT" on screen


If you have recently changed your thermostat to this one, It may not be compatible with your system. If you have a heat pump system, your thermostat will not work with a heat pump. You will have to install a thermostat that is compatible with a heat pump.
-Said that, assuming this has worked in the past during the heating season, some times the switch slides on these thermostats are fairly tempermental in that the switch slide contacts inside the control board sometimes do not make contact and if jostle around a bit, will maybe make contact. You can also remove the front plate from the base plate and check the wire are properly attached and not loose. While you have it off, check the hg he switch to make sure it is selected properly. If you have a gas or oil furnace it should be in hg. If you have electric heat it should be in he.
Depending on the age of the thermostat, you may need to get a new one because of the slides do wear out and tend to give unreliable performance. If you replace the thermostat, may I recommend you get a Honeywell built thermostat. Many of the cheap thermostats are cheap and poorly constructed and become unreliable. On cold days or hot days air conditioning is essential for comfort, and the money spent for a good thermostat is money well spent.
Hope this helps.

Dec 20, 2014 | Hunter Set and Save Programmable...

1 Answer

Aux keeps coming on on regular heat is there something wrong with heat


See if it happens only when your temperature of the room is more than 3 degrees of your setpoint temperature. Since you have a heat pump, the auxiliary (electric heat strips) is use for backup of the heat pump when it can't keep up. The heat pump will run by itself if it can maintain temperature within a couple degrees. If it is too cold outside to handle the load or you set the temperature more than 2 degrees past room temperature, the auxiliary will turn on. The thermostat has a memory of how long it takes to reach desired temperature. If it goes into auxiliary mode trying to satisfy setpoint during the last call for heat, it will start the next call for heat in both aux & heat pump mode until the thermostats algorithm (timed program) allows only the heat pump to run. Not sure if you have an air to air, or geothermal heat pump. The outside air temperature will affect only the air to air system ie. when the temps drop outside, the heat coming out of your vents will be cooler...the air to air systems drops efficiency when the outdoor air drops.

Nov 08, 2013 | Honeywell TH3210D1004 PRO 3000...

1 Answer

Honeywell thermostat blank screen on cool


I wonder if they shorted a wire a during install. That is where I would begin.

May 14, 2013 | Honeywell Rth2310b 5-2 Day Programmable...

1 Answer

Wiring a thermostat


Are you changing out thermostat? If so you must turn off power to your furnace or air handler. You should mark or write down each color and what terminal it was removed from. example= red from term r=green from term.=g yellow from y... Be careful, some thermostats are wired different according to type of system you have. Heat pumps are different than straight cools and the thermostats sometimes have setting or little switches. Honeywells have installer set up guides in package. Read it carefully

Sep 16, 2012 | Honeywell RTH3100C - Digital Heat Pump...

1 Answer

Heat pump is in heat mode 4 hrs. in to the


Hi, this is your programmable thermostat not being programmed right. If you have the manual, set your times and temperatures for both heating and cooling to cool or heat at the times you want it to. I am not sure where you are, and if you want to use just heat or cool, but you can set it to run on just one or the other, or to auto change over. Just be sure to run it in the auto mode. I can't tell you how to over the net as there are so many models of thermostats, but if no manual, you may be able to get one by getting the model number off your stat and name, go to a place that sells that stat and they can tell or show you how to set it up. I hope this has been of help to you. Let me know please.
Shastalaker7

Dec 23, 2009 | Ruud Handle Air Conditioner

3 Answers

Honeywell Thermostat RTH 7500


Assumed all the wiring are correct,

to change from manual switching from heat to cool, press [system] button ( left ) to go into system setting.

then press and hold the [fan] middle button untill option display 120

use up down button to select option 300 ( Manual/Autochangeover) ,

select 0 for manual, 1 for automatic. ( read caution in page 22 of installation manual )

Good luck

Sep 30, 2008 | Air Conditioners

Not finding what you are looking for?
Air Conditioners Logo

Related Topics:

79 people viewed this question

Ask a Question

Usually answered in minutes!

Top Air Conditioners Experts

Dan Webster
Dan Webster

Level 3 Expert

8147 Answers

Bill Long

Level 3 Expert

577 Answers

Tim Whalen

Level 3 Expert

3056 Answers

Are you an Air Conditioner Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...