AC inside fan doesn't come on AUTO

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  #1  
Old 07-21-04, 09:54 AM
zampak
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AC inside fan doesn't come on AUTO

I have Goodman CPKJ heatpump with CHRONOTHERM thermostat. Here are the symtoms.

The outside unit keeps running when COOL on. The inside FAN doesn't run when in AUTO mode. If I leave the FAN ON then the AC works fine Cooling correctly.

Is the thermostat not working correctly or something in the AC unit causing it to do this?

Thanx
 
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  #2  
Old 07-21-04, 11:42 AM
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It's in the stat. That's a nice one though they usually last forever.
 
  #3  
Old 07-21-04, 12:39 PM
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jump g and Y, call for cool. if the fan runs, it is the stat

i am with matt, but i have a different opinion on those chronotherm tstats!!
 
  #4  
Old 07-25-04, 09:50 PM
greenjade800
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I have the same problem. Mine is Goodman also. I have 2 tech persons came over, They replaced thermostat(Honeyewell) a few days ago. but I still have the problem. Did you fix your problem? Please tell me. Thanks.
 

Last edited by greenjade800; 07-25-04 at 10:00 PM.
  #5  
Old 07-26-04, 05:56 AM
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If you take the thermostat off the wall and put R+Y+G together and everything comes on...(indoor fan, outdoor fan, and compressor) then the thermostat is bad. If everything works it's your thermostat if something don't work post back and let us know.

** Do not let the outside unit run for any amount of time without the indoor fan running.**
 
  #6  
Old 07-26-04, 06:46 AM
greenjade800
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I forgot to tell you that the inside fan work most of the time, but sometimes doesn't work. That is hard part. When the tech persons came to my home, it works all the times. They can't find any problems. They did replace the old thermostat with new one. Someone on this board said(other title), it is capacitors problem. I don't know where it is. inside or out.
 
  #7  
Old 07-26-04, 10:56 AM
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Wink

Greenjade
I forgot to tell you that the inside fan work most of the time, but sometimes doesn't work. That is hard part.
Like has been said what do you have there what units.like Matt and Mike said what do you get when you jump R to G does the blower come on all the time? Did any of the tech's check the blower motor with a amprobe also they should have checked the capacitor out? Its there right on the inside blower.

ED
 
  #8  
Old 07-26-04, 05:05 PM
greenjade800
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Thanks. I didn't try R and G jump(I have to work), but I did wash the out side of Unit. Do you want me to try when the problem happens or I can try it anytime even if it works fun? Tech did turn up(16 point check point, but I don't know the details) and installed T-stat. The unit is electric central air-conditioning(heat and cool). It made by Goodman.
 

Last edited by greenjade800; 07-26-04 at 05:18 PM.
  #9  
Old 07-29-04, 07:31 AM
greenjade800
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Question

I did jump R and G today after it is not work again. It didn't work. The fan did run. I also jumped R and, w and y. those are OK. Any idea? The tech will came in today. They have been here twice before. What should I tell him? Thanks.
 
  #10  
Old 07-29-04, 12:33 PM
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I did jump R and G today after it is not work again. It didn't work. The fan did run.
If R to G made the fan run then its in the tstat

ED
 
  #11  
Old 07-29-04, 12:57 PM
greenjade800
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I am sorry. The fan did NOT run when I jumped R and G. The tech said it is time delay problem, so he charged me $235 for the part and labor(It took about 1 hour). They charged me $116 labor before even if the T-stat didn't have any problem(they thought the problem was t-stat).
I called a few places, their prices are between $125-195 for time delay problem. Do you think the Collins Comfort Masters charged me too much?
Thanks.
 
  #12  
Old 07-29-04, 02:52 PM
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the part wholesales for @20 bucks

i would have charged 100 installed with diagnostic
 
  #13  
Old 08-02-04, 12:31 PM
zampak
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Can someone explain what time delay part is_ where it is located and how to replace it? I have opened the outside unit of the heatpump (Goodman) before. I have never looked inside the attic fan unit.

I am having a similar problem where the fan doesn't come on sometimes during cool cycle in Auto mode. So under normal operation _ once in couple of days the fan doesn't come on... causing the temp to shoot higher. Whats interesting is --when this happens, if I change the fan position from Auto to ON, the fan still doesn't come on. If I turn off the COOL and then switch the fan to ON then it comes on fine all the time.

I tried jumping RGY and both outside and inside fan comes on. I have a dual stage heatpump so it took a while to find the thermostat that will work with it. I got a new Honeywell 3611 stat.I will replace it tonight and see if the intermittent fan problem goes away.

Somehow I get the feeling from this discussion that I also have a time delay problem? Please help...

Thanx
 
  #14  
Old 08-02-04, 02:22 PM
bigjohn
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I think what the guys are referring to is a time delay type INDOOR FAN RELAY. [it is located inside the control box in the air handler] They are common on today's higher efficiency units. There are several types, the most common is known as post purge time delay fan relay. It works like this- when the fan switch on the thermostat is in the auto position and the thermostat is satisfied on a call for cooling [ie: shuts off the cooling] the fan relay keeps the indoor fan running for about a minute or so to purge the cooling coil section and ducts of any residual cool air that is still there. Works out on paper but, when these relays start to act up, they can be very intermittent. It will work ok one cycle then not the next and so on. You have to catch it in the failure mode and do some electrical checks to verify. Of course, Murphy's law says it will always work ok if the repairman is there.
 
  #15  
Old 08-03-04, 10:28 AM
zampak
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How difficult is it to replace the time delay unit? I have never opened the attic air handler unit. I have opened the outside unit to check the caps etc.

I just replaced the thermostat. I will check if the intermittent fan failure in auto mode still continues.

Any advice regarding this would be appreciated.

Thanx
 
  #16  
Old 08-03-04, 12:40 PM
greenjade800
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That part is very small(like a egg). It is on the inside of big box. It is inside of the house(on top of the roof), not outside.
 
  #17  
Old 08-04-04, 07:01 PM
zampak
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AC blower fan intermittent

Even after replacing the thermostat, I am still seeing the blower fan fail once in a day... especially when its very hot outside. Thermostat calls for cool. The outside unit runs but the blower fan doesn't run.

I have ruled out thermostat as a failure mode. How do I debug this to figure out that its the time delay relay thats causing the problem? I have Goodman AC blower unit A49-20 in the attic. I have a simple diagram which shows the names of different parts of the blower unit. (from Sears)

Also, can someone explain what happens when outside unit runs with inside fan not working? This has happened a couple of times for a few hours. The unit is still running when I turn FAN to ON and cools fine.

Thanx in advance.
 
  #18  
Old 08-05-04, 12:22 AM
bigjohn
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When it fails, test for 24 volts from G to C terminals at the low voltage terminal strip in the air handler. If yes, the fault is inside the air handler controls> most likely the fan relay. If no, the fault is in the wiring or the thermostat. It's not a good idea for the outdoor unit to be running with the indoor fan off; it could damge the compressor.
 
  #19  
Old 08-05-04, 08:38 AM
zampak
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Thanx BigJohn... I opened the air handler and then traced the circuits. I identified the Fan Time Delay relay. While I was making sure that the connections are tight to the fan relay, the top piece (with connections 1 2 3) came off and a small circular disc fell off. I replaced the disc back and now the fan comes on all the time.

It appears that something is wrong with the timedelay unit. Is the top suppose to come off so easily? What did I do wrong that the fan is stuck on? Is having the fan on all the time going to do any harm? The outside unit comes on according to the thermostat.

Thanx
 
  #20  
Old 08-05-04, 09:01 AM
bigjohn
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It sounds like you found the problem in that the blower time delay relay is bad [this is a common failure]. There are 2 types- one that cycles an additional power relay for the fan motor and one that has the hi power relay contacts for the fan motor built in. Go to www.icmcontrols.com to see what the generic repalcements look like. It won't harm anything to have the indoor fan running all the time.
 
  #21  
Old 08-06-04, 11:00 AM
zampak
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How does Time delay relay work?

Thanx for all your help.

It was very hard to get the Time delay relay from any of the AC shops. You had to be a contractor to get it. I found one place who sold me the relay and the cap across the fan. 25 bucks for both the parts.

I just replaced both parts in the morning. So far things seem to be working.

How does the time delay relay work anyway? I opened the broken one. It just seems to have a couple of metal disks in it. Is it temperature sensitive contacts.
 
  #22  
Old 08-06-04, 04:13 PM
bigjohn
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These are usually what we call a Delay on Break type relay. IOW- when the power to the relay coil is removed there is a delay period before the contacts open shutting off the load which in this case is the indoor fan motor. You usually set it for 60 seconds [if it's adjustable, the lower cost ones have fixed times]. This means that the fan motor will continue to run for one minute after the thermostat shuts off the outdoor unit [assuming you have the FAN switch on the thermostat set to AUTO]. It sounds like your old one is probably some type of thermal relay.
 
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