Air handler problem - http://www.hvacmechanic.com/ Forums
Original message
| George R
 |  "Air handler problem"
, posted Sat 5 Jul 17:57:  
Hi folks,
I have a problem with my air handler not coming on when the tstat turns if off/on. The compressor comes on but the handler doesn't always come back on after reaching the maintenance temp.Sometimes it does, sometimes it doesn't. (It most always turns off when it's supposed to)
I have installed a new Honeywell RTH6300B stat, which, I assume is wired correctly or it wouldn't work at all. I had the same problem with the old thermostat, which is why I changed it out. I tried tightening the connections but it still is erratic. Sometimes just cycling the circuit breaker will turn it on, other times it has to sit a while with the breaker off.This is a Goodman AH30-08C. Any ideas?? Thanks a bunch.
[this message was edited by George R on Sat 5 Jul 17:59] |
| Replies:
|
| allen1980
| "Re(1):Air handler problem" , posted Sat 5 Jul 18:36
how old is your unit?it sounds as if the fan relay is bad.
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| | George R
| "Re(2):Air handler problem" , posted Sat 5 Jul 18:47:
quote:
how old is your unit?it sounds as if the fan relay is bad.
...
It's maybe 10/12 years old. Is the fan relay id'ed on the schematic?
If the relay is bad, would it be intermittent??
Right now it's running great. After I go to bed is when it most commonly occurs.
Is there a test I can do on the relay??
when you refer to the 'fan' are you talking about the squirrel cage??
Thanks
[this message was edited by George R on Sat 5 Jul 18:49] |
| | Houston204
| "Re(3):Air handler problem" , posted Sat 5 Jul 20:54
Goodman fan relays resemble heat sequencers. You might try Johnstone supply.
Probably have a number like...
H1-25C65-115
12S50 H24V 305234
"Tip of the Day" Remember to remove power first.
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| | George R
| "Re(4):Air handler problem" , posted Sat 5 Jul 21:21
Hooray, that looks a lot like my set up except for the dust.(I cleaned mine) I have 60amp breakers but I 'm not going to open it up again until tomorrow am. Is that fan control the device I'm looking for?? Will the p/n be on the device?
Johnstone doesn't seem to have a similar item. How about Grainger???
Your help is greatly appreciated.
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| | Houston204
| "Re(5):Air handler problem" , posted Sat 5 Jul 21:27
I don't know, I only get them from Johnstone. (Even though Goodman is here in Houston and we have an acount there as well)
Wholesalers don't like selling to the general public.
Yes the part labeled fan control (with a green wire from your stat) is the part you need.
"Tip of the Day" Remember to remove power first.
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| | George R
| "Re(6):Air handler problem" , posted Sun 6 Jul 09:34
OK Houston, The p/n checks out with what you gave me. There is a red wire that comes out of the front bottom of the fan control that is not connected in my set up. As near as I can tell from your pic this wire should go to a spade on the heat sequencer (M1 as near as I can see, it's difficult to tell for sure because of the number of wires) It appears to not have ever been hooked up. Could this be a problem??? Again, the fact that this problem is intermittent bugs me more than anything else.
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| | TnNATE1412
| "Re(7):Air handler problem" , posted Sun 6 Jul 09:51
The red wire should NOT be hooked up if the black wire is connected. That is another motor speed wire, and if both are hooked up, you WILL burn the motor out.
Goodman (Janitrol) is great for intermittent blower operation, just before the control goes out completely. You can do away with the time delay, by just having a 24 Volt relay coil, (90-293Q or 90-340, etc.)
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| | George R
| "Re(8):Air handler problem" , posted Sun 6 Jul 10:22
Well, that settles that. Thanks.
Does the 24v install in place of the present fan control?
Apparently my fan control has given up the ghost. It no longer works at all.
Thanks again
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| | Houston204
| "Re(9):Air handler problem" , posted Sun 6 Jul 11:56:
The only drawback to losing the time delay on the fan, when your heat strip control also has a time delay, is that the heat strips will glow red and get really hot for 30 seconds every time it cycles off.
I recommend the original replacement to reduce wear on your heat strips. (But of the 2 alternates listed I would get the 90-340)
If you were not using red before, do not use it now. The pictured AHU is smaller than yours and using a different speed.
"Tip of the Day" Remember to remove power first.
[this message was edited by Houston204 on Sun 6 Jul 13:22] |
| | George R
| "Re(10):Air handler problem" , posted Sun 6 Jul 12:24
I agree, there are several distributors around here who should carry the right part. Unfortunately, I don't know of any who are open on Sunday. So I guess I'm stuck sweating until tomorrow. Thanks again, especially to Houston204.
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| | Houston204
| "Re(2):Re(10):Air handler problem" , posted Sun 6 Jul 13:28:
Forget sweating. I would find the wire going to the motor and plug it in where the power feeds your fan relay.
The fan would always run, but the house would cool.
There is only 3 high voltage wires on the fan control (at terminals 1, 2 and 3)
In my picture light blue is 24 volt common, green is 24 volt fan signal.
Terminal 1 appears to be the fan motor wire, the brown wire at terminal 2 appears to be fan from your heater control.
The relay on my desk shows continouity between 1 and 2 with no demand.
Violet is high voltage common and red appears to be my low speed. I would move terminal 1 wire (yours is black)to the red side of the breaker.
1 and 2 are on the same side of your relay, with 1 in the middle of your tree and 2 on top. 3 is opposite 1 and should be your hot leg.
I would trace your wiring and not go by my picture of someone else's unit. IT IS HARD TO MAKE THIS OUT FROM THAT PICTURE since they used wired ties and I don't have a diagram available.
"Tip of the Day" Remember to remove power first.
[this message was edited by Houston204 on Sun 6 Jul 13:55] |
| | George R
| "Re(3):Re(10):Air handler problem" , posted Sun 6 Jul 14:42
It makes sense so far. I hooked the black wire to the red breaker and I'm going to power it up here in a few minutes. Some of my wires are slightly different,I have continuity between 1 & 2 as you indicated. that brown wire is red on my box and doesn't go anywhere. The light blue wires are a deep blue but seem to go to the same place as the pic. I can't see any real problem, I can always turn it off before the house burns down.
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| | George R
| "Re(4):Re(10):Air handler problem" , posted Mon 7 Jul 12:01
the system powers up ok with the fan running full time.
I have changed the fan control relay, but that made no difference in the overall operation. the fan doesn't come on when the control is wired into the circuit.
Could I have it wired wrong?? The new unit looks like the old unit except for some double spades. Can you tell me which wires (color)go to which lugs? Could there be some other problem?
Thanks
(the sales receipt for the new relay says No Return)
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| | George R
| "Re(5):Re(10):Air handler problem" , posted Mon 7 Jul 14:06
Well, it appears that the unit is not wired in accordance with the schematic that's stuck on the door. It's been more than a few years since I had to read a schematic, but it doesn't match up as near as I can tell. I suppose that this could be a result of the install set up and I don't have an installation manual.
Is this normal????? I'm running per suggestions from Houston204 at the moment but I would like to get the damned thing to work properly. What is the likely hood of getting a bad relay new in the box??
Thanks
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| | Houston204
| "Re(6):Re(10):Air handler problem" , posted Mon 7 Jul 22:36
Did you buy a goodman fan relay, a standard fan relay, or a heat sequencer? The Goodman relay and a sequencer are delay on make as well as delay on break.
Do you have a digital camera?
Pictures can be posted on this site using www.photobucket.com
upload your pics, select IMG Code, right click and paste on your post.
That connection diagram would be great.
"Tip of the Day" Remember to remove power first.
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| | George R
| "Re(7):Re(10):Air handler problem" , posted Tue 8 Jul 02:49
I've got pix on photo bucket, but don't know how to proceed. My eyes have had it for tonite. If you can tell me where to with the pix I'll do it in the morning. It's probably right in front of me, but when my eyes get tired, they don't work very well.
Thanks
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| | George R
| "Re(7):Re(10):Air handler problem" , posted Tue 8 Jul 00:19
There isn't any manufacturer on the relay. It looks just like the old one except that two of the terminals are doubles,and the base plate is smaller.(probably made in china like everything else these days)
Approximately how long is the make delay. It could be that I didn't wait long enough.
I have digital cameras. I will try to take a pic or 2 tommorrow am. and post them as you suggested. You want a picture of the schematic right??
I'm in FL so there are a couple of time zones between us.
Thanks again
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| | George R
| "Re(8):Re(10):Air handler problem" , posted Tue 8 Jul 09:20:
Houston204,this is my first shot so 'patience' please. http://s340.photobucket.com/albums/o332/GrampaJones /
Not sure why that didn't come out as a hot link, but I'm trying to find out.
(ahhhh, success in one of it's milder forms)
[this message was edited by George R on Tue 8 Jul 09:26] |
| | George R
| "Re(10):Re(10):Air handler problem" , posted Tue 8 Jul 12:00
Houston204; If I can read this one, anyone can. 
If you need more, just let me know
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| | theduke03
| "Re(2):Re(10):Re(10):Air handler problem" , posted Tue 8 Jul 21:53
Well the diagram and your pictures disagree. Where is the black blower lead? That should be on terminal 1.
The brown wire should be on terminal 2.
That disconnected red wire should be on terminal 3 .
Do you have a meter?
"My dad was the most feared furnace fighter in Northern Indiana."
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| | George R
| "Re(3):Re(10):Re(10):Air handler problem" , posted Tue 8 Jul 22:21
Yep, I have a meter
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| | Houston204
| "Re(3):Re(10):Re(10):Air handler problem" , posted Tue 8 Jul 22:11:
That is someone else's pic. The other poster is using low speed.
I agree, If that is indeed the correct part...
Black(Hi speed) to 1
Brown(M2) to 2
Red(M1) to 3
Do not use fan red (Low speed)
"Tip of the Day" Remember to remove power first.
[this message was edited by Houston204 on Tue 8 Jul 22:12] |
| | George R
| "Re(4):Re(10):Re(10):Air handler problem" , posted Wed 9 Jul 00:16
quote:
That is someone else's pic. The other poster is using low speed.I agree, If that is indeed the correct part...Black(Hi speed) to 1Brown(M2) to 2 Red(M1) to 3 Do not use fan red (Low spe
...
The red wire coming off term 3 is not connected. this is not the wire from the fan motor. Is this wire supposed to hook up to M1?? It wasn't connected when I first opened the system. Just hanging there.
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| | George R
| "Re(4):Re(10):Re(10):Air handler problem" , posted Tue 8 Jul 22:24
That's the way I had it hooked up with the green to the upper left and blue to the 2 bottom spades.
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| | Houston204
| "Re(2):Re(10):Re(10):Air handler problem" , posted Tue 8 Jul 21:46
So, black (fan) is normally closed to brown (heater control). When 24 volts is sent to green (G), black closes to red (power) and opens to brown.
Did you ask for a Goodman fan control when you purchased this relay? If you ended up with a sequencer, it will not work properly. Johnstone or Godman would be the place to get that part.
If you can't get the OEM relay, use the 90-340 relay.
(Or any double pole double throw relay with a 24 volt coil)
You will only use a single pole, but the double pole relays are more reliable.
"Tip of the Day" Remember to remove power first.
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| | George R
| "Re(3):Re(10):Re(10):Air handler problem" , posted Tue 8 Jul 22:18
At the present, I have the blower (black) hooked to red side of the circuit breaker. At least I can get some air. I just turn it off occasionally.
I asked the clerk for the relay for the Goodman AW30-08c air handler. That's what he sold me.(what's in the picture)It is essentially the same as the old one, except that the base is a bit smaller. The p/n is H1-25c65-115 Which is the same as the p/n on the old one. The sales receipt calls it a 'B13707-38 Goodman air handler relay'. I hooked it up earlier with the black wire going to the #1 term and let it go for about 5 minutes, but it wouldn't come on. (the air handler) I don't know how long the delay should be.?????
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| | Houston204
| "Re(4):Re(10):Re(10):Air handler problem" , posted Tue 8 Jul 22:29
30 seconds
If you use a standard relay and wire it as shown, it will run without overheating the heat strips when they cycle off (in heat mode).
Red = M1
Brown = M2
Black = hi speed.
"Tip of the Day" Remember to remove power first.
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| | George R
| "Re(5):Re(10):Re(10):Air handler problem" , posted Tue 8 Jul 22:48
Ok, if I use the relay, how do I hook up the tstat??
The current install has green and blu wires going to tstat and on blue wire going to M4 on what I assume is a sequencer????
Do you think the new relay is defective??
Thanks
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| | Houston204
| "Re(6):Re(10):Re(10):Air handler problem" , posted Tue 8 Jul 23:16:
Verify that you have 24 volts between green (fan signal from stat)and blue(24Volt common) before you condemn that new relay.
Be Careful.
M4 is a high voltage contact to your heat strip.
Blue is low voltage common.
The diagram is a little misleading at first glance.
Green and blue will wire as shown in the picture (refresh the pic).
"Tip of the Day" Remember to remove power first.
[this message was edited by Houston204 on Tue 8 Jul 23:19] |
| | George R
| "Re(7):Re(10):Re(10):Air handler problem" , posted Tue 8 Jul 23:25
Is the low voltage ac or dc???
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| | George R
| "Re(8):Re(10):Re(10):Air handler problem" , posted Tue 8 Jul 23:32:
Voltage between GRN and BL is 26.5vac
measured between the un marked terminals of the new relay (extreme top and bottom) whith the system energized.
[this message was edited by George R on Tue 8 Jul 23:38] |
| | Houston204
| "Re(9):Re(10):Re(10):Air handler problem" , posted Tue 8 Jul 23:37
bad relay
"Tip of the Day" Remember to remove power first.
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| | George R
| "Re(10):Re(10):Re(10):Air handler problem" , posted Tue 8 Jul 23:40:
Just so I can be prepared when I take it back, could I have done something to screw it during installation or power up/down????????
Just to be sure I measured 'across' the relay as well as between the spade where the green wire hooks up(new relay) and the bottom spade on the 'sequencer' hooks up with blue wire.???? safe to assume the relay is stuck???
[this message was edited by George R on Tue 8 Jul 23:43] |
| | Houston204
| "Re(2):Re(10):Re(10):Re(10):Air handler proble" , posted Tue 8 Jul 23:49:
Wiring high voltage to the low voltage terminals could damage your relay.
That might be one reason that many vendors will not sell to the general public.
"Tip of the Day" Remember to remove power first.
[this message was edited by Houston204 on Tue 8 Jul 23:50] |
| | George R
| "Re(3):Re(10):Re(10):Re(10):Air handler proble" , posted Wed 9 Jul 00:05
Should the low voltage terms be N.O. I measured across two bottom terminals of the old relay and it closed (shorted) and that is apparently what is wrong with the new one. I haven't energized the system with the wiring incorrect. So the new relay is obviously defective if it is shorted, or stuck closed (assuming it is n.o.) correct???
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| | Houston204
| "Re(4):Re(10):Re(10):Re(10):Air handler proble" , posted Wed 9 Jul 00:13
The one on my desk measures 106 ohms across the coil.
It is a faulty one that I removed from a unit, and I have stepped on it, so I'm not sure what the correct resistance should be across the coil. It should have resistance though.
"Tip of the Day" Remember to remove power first.
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| | George R
| "Re(5):Re(10):Re(10):Re(10):Air handler proble" , posted Wed 9 Jul 00:21:
I just rechecked the old one. It shows 00.1 ohms resistance??
I will check the new one again when I shut the system down.
The new one doesn't even show the .1ohm It's a dead short.
[this message was edited by George R on Wed 9 Jul 00:27] |
| | Houston204
| "Re(6):Re(10):Re(10):Re(10):Air handler proble" , posted Wed 9 Jul 00:31
It's not actually a coil. It's a snap disk.
"Tip of the Day" Remember to remove power first.
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