bad fan relay switch?

Reply

  #1  
Old 11-20-02, 02:52 PM
lsteele75
Visiting Guest
Posts: n/a
bad fan relay switch?

I changed our old mercury switch thermostat this past weekend with a Hunter 4100B thermostat. Everything worked fine until the second night, and then the fan first kept kicking on at very short intervals and then wouldn't shut off at all when the proper temp was reached. I called Hunter for technical assistance and was told to disconnect the G wire, which I did. The fan continued to run even with this wire disconnected, and the Hunter rep told me that there is most likely a problem with the fan relay switch. Do you have any idea how I would change this? The blower is a Rheem, and the mfg. tag has paint overspray on it, but it looks like the model # is KEAB 1415 J; it's got to be as old as this house, which was built in 1984 or so. Thanks for any feedback you can provide.

 
Sponsored Links
  #2  
Old 11-20-02, 07:26 PM
rclhvac
Visiting Guest
Posts: n/a
try removing stat & connecting the red & white wires together.
This should bring on your heat- let it run for alittle while then disconnect them- if it seems to operat properly - its the stat- if it continues to malfunction then its the equipment
good luck
 
  #3  
Old 11-20-02, 07:30 PM
GregH's Avatar
Super Moderator
Join Date: Jan 2001
Location: Manitoba
Posts: 9,903
Likes Received: 3
lsteele75:
What type of furnace is this?
Is it possible that the fan selector switch is in the on position or the summer fan set to on.
To change the relay you would have to locate it, mark the wires and then remove it to be able to get a replacement. The new relay may not be exactly like the old one, so be prepared to figure out how to connect it.
 
  #4  
Old 11-20-02, 07:58 PM
lsteele75
Visiting Guest
Posts: n/a
GregH,

Thanks for the feedback. For starters, I don't know a lot about heating and cooling systems, so I'm not really sure how to answer your question. What we have in our home is a blower (some people might call it a forced air) unit which circulates the cool or warm air through our home. We've only been in this house 1-1/2 years, so I don't know a whole lot about this particular system either, but evidently, there is a self-contained heating element in the blower unit which warms the air. In the summer, this is bypassed and the air is cooled by the compressor of the a/c unit outside.
 
  #5  
Old 11-20-02, 09:39 PM
rclhvac
Visiting Guest
Posts: n/a
Originally posted by rclhvac
try removing stat & connecting the red & white wires together.
This should bring on your heat- let it run for alittle while then disconnect them- if it seems to operat properly - its the stat- if it continues to malfunction then its the equipment
good luck

I assumed it was working fine before new stat -am i right?
 
  #6  
Old 11-20-02, 10:26 PM
lsteele75
Visiting Guest
Posts: n/a
Hi Rick,

Thanks for your feedback. You're correct - the stat was working correctly prior to my changing it. I had also checked the other night to be sure that it was on "auto" and not "on." My husband had put it to the "on" position, but even several minutes after I put it back to "auto," it still wouldn't kick off. I even tried shutting off the breaker switch that powers the a/c system - still no luck. I haven't had a chance to yet, but I will be trying your suggestion and will let you know if it works.

Thanks again so much.
 
  #7  
Old 11-21-02, 04:49 PM
Member
Join Date: Nov 2002
Location: Massachusetts
Posts: 1,815
Camstat

On your furnace you most likely have a camstat or fan AND limit control by Honeywell. Some of the Honeywell fan and limit controls have a white plastic ON/AUTO switch at the furnace. This control looks like a silver cover on it about the size of a wall switch. Under the cover is a round dial with different settings on it that are adjustable. The plastic knob has a push/pull action to make the fan run on a call or wait till it warms up to a preset temperature. The blower runs as long as the plenum box is at the lowest setting you see on the dial. You can try raise this a bit. It may just have a worn spot on it. Don't raise it much more than about 110F. This is used to ring out all the heat. OH! did hubby set the heat anticipator in the thermostat to the same setting as the old one? Make sure the air filter is clean also, if it has a belt change it annually and oil the motor with 5 - 10 drops on each end, if it has oilers.
 
  #8  
Old 11-21-02, 05:06 PM
hvac4u's Avatar
Member
Join Date: Aug 2001
Location: NW atlanta
Posts: 3,147
HUNTER TSTATS

they should stick to fans! have seen units do what you describe and almost every time found a hunter tstat on the wall. some techs call these "energy stealing" tstats, as rclhvac said, tie white and red, if no problem, replace stat.
 
  #9  
Old 11-21-02, 05:17 PM
GregH's Avatar
Super Moderator
Join Date: Jan 2001
Location: Manitoba
Posts: 9,903
Likes Received: 3
lsteele75:
I am thinking that based on what you are telling us the problem most likely lies in the thermostat or the connections.
Did you mark each wire that was removed?
You may want to reinstall the old stat if it was working when you removed it.
If there is a possibility that the wires got mixed up, you could go to the furnace and mark down the terminal ID and which color wire goes to it. You can then confirm that the red wire is connected to R and the white wire to W. Most furnaces have terminal ID's that match the thermostats.
In my rural area the color coding is rarely adhered to.
 
  #10  
Old 11-21-02, 05:35 PM
Member
Join Date: Nov 2002
Location: Massachusetts
Posts: 1,815
Thermostats...

If you decide to get a replacement thermostat, try the 9701i invensys by Robert Shaw. You can use a remote temperature sensor, Temperature averaging, heat pump, gas, or electric, it programs 5+2, 5+1+1, or individual, single stage heat and cooling, programmmable fan auto changeover...easy menu driven programming. I programed it without reading any directions. The sensor is 2 wire any order. a terminal for outside temp also. Easily wired. BUT it requires both the R and C wire from the low voltage transformer. They're the best I've seen so far. They even have idiot lights for heating, cooling, and fan when running. The remote sensor is about the size of a thumb.
 
  #11  
Old 11-21-02, 08:14 PM
lsteele75
Visiting Guest
Posts: n/a
Dear Everybody,

Thanks so much for all your help and suggestions. The problem seems to be solved - at least for the moment. I had shut off the breaker on the main panel and left it off for a few days after the malfunction. I have the t'stat set to 68, the current temp is 74, and when I put the thermostat on auto heat, it (thankfully) didn't kick on. I went a little crazy the first couple of days reprogramming the temp settings. Is it possible I confused the blower? Anyway, if I have any more problems I'll be sure to call on you guys again. Thanks so much for being there. Also, to my friend who says his wife accuses him of being inattentive, I'm sure you listen to all the important stuff.

Thanks again.
 
  #12  
Old 11-22-02, 04:15 AM
Member
Join Date: Nov 2002
Location: Massachusetts
Posts: 1,815
Make sure you separate the cooling setpoint from the heating setpoint by a minimum of about 4 degrees. Make sure there is nothing warm under the thermostat (ie TV, Radio, Coffee maker...) Keep in mind, setback thermostats either programmable or manual require a 4 hr window BEFORE you begin to save energy. Most people meet this requirement when sleeping. There are some night owls out there or a family member on the 11-7 shift that stay up late while others sleep. It depends on the family.
 
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
Display Modes