Blower Stays On
#1
01-18-17, 09:18 AM
Blower Stays On
Unit: Rheem RGRA-10EZAJS
I accidentally left a window open last night with the HVAC on so it ran the whole night. It did not get extremely cold but cold enough that it would trip the thermostat. This morning I noticed the unit would not shut off. After investigating the blower just stays on. I turned off the thermostat, nothing. I opened the HVAC unit and saw that the yellow light was flashing rapidly non-stop (no sequence or anything). I can manually shut the unit down and wait a while, it will stay off. As soon as I engage the thermostat and let it run through a quick heating cycle the blower will stay on or re-engage shortly after the cycle and the yellow light will once again start to flash.
What and where can I check? I have read that the limit switch might be bad and this could cause the blower to stay on. I have a multimeter, how can I check if it is bad or not?
There are also 2 burner limits/switches or maybe they are reset buttons, could one of these also be a culprit and how can I test for that? I tried to press one in but did not seem to go (I did not try to force it, just gentle push). Maybe I have to pull it out to reset it?
I have very limited experience with my multimeter so please dumb it down for me or point me to a link that would explain any stupid questions I might have.
Thank you in advance!
Limit part #: 47-25350-07
Limit manual reset: 47-22861-02
I accidentally left a window open last night with the HVAC on so it ran the whole night. It did not get extremely cold but cold enough that it would trip the thermostat. This morning I noticed the unit would not shut off. After investigating the blower just stays on. I turned off the thermostat, nothing. I opened the HVAC unit and saw that the yellow light was flashing rapidly non-stop (no sequence or anything). I can manually shut the unit down and wait a while, it will stay off. As soon as I engage the thermostat and let it run through a quick heating cycle the blower will stay on or re-engage shortly after the cycle and the yellow light will once again start to flash.
What and where can I check? I have read that the limit switch might be bad and this could cause the blower to stay on. I have a multimeter, how can I check if it is bad or not?
There are also 2 burner limits/switches or maybe they are reset buttons, could one of these also be a culprit and how can I test for that? I tried to press one in but did not seem to go (I did not try to force it, just gentle push). Maybe I have to pull it out to reset it?
I have very limited experience with my multimeter so please dumb it down for me or point me to a link that would explain any stupid questions I might have.
Thank you in advance!
Limit part #: 47-25350-07
Limit manual reset: 47-22861-02
#2
01-18-17, 10:14 AM
Group Moderator
As soon as I engage the thermostat and let it run through a quick heating cycle the blower will stay on or re-engage shortly after the cycle and the yellow light will once again start to flash.
Is the furnace heating as long as the thermostat is calling for heat or does it heat for a few minutes and then default to blower only ?
We aren't there... we're relying on you to relay to us the exact order of events.
That yellow LED is a flashing a fault code. Count the pattern. You can tell us what you get or look at the back of the blower door where they are listed.
The two limits with the buttons are for flame rollout. If they were tripped there would be no burner function.
#3
01-18-17, 10:42 AM
As soon as I engage the thermostat and let it run through a quick heating cycle the blower will stay on or re-engage shortly after the cycle and the yellow light will once again start to flash.
- Thermostat set to on
- Turn up the heat so it trips the HVAC to start its cycle
- HVAC engages as expected and produces heat (its internal cycle as far as blower on, ignition, etc all seem normal).
- I then lower the temp on the thermostat so that you hear the *click* which disengages the HVAC
- HVAC stops producing heat (burners turn off) but the blower continues to run.
Step 5 seems almost normal except for the part where the blower just never turns off. Usually it turns off after a minute or so but this just keeps going.
I initially also thought to count the flashes to see if there is a fault code but it is just a non-stop rapid flash of the light. I watched it for a minute, it just blinks rapidly (maybe 2 blinks a second or so?) non-stop. I checked the blower door but it only has the "blower performance data" which is pipe sizing and air flow table, unfortunately there is nothing else on that door (or anywhere else on the unit).
Ok, that is good to know about those limit switches! One less thing that I have to check then.
Thanks for your reply and I hope this gives you a better idea of what I could check next.
#4
01-18-17, 11:04 AM
Group Moderator
This should be an excerpt of your board. The yellow LED should be labeled flame. It flickers only when the burner is lit.
Since you are getting a normal heat cycle.....the limits are ok. Any open limit will not allow the burner to light.
If you look at the board.... I highlighted the fan control area. This board shuts the blower off after a heat cycle by timer. It would appear that board may be at fault. This is assuming the stat is not in the FAN ON mode. You could remove the stat and see if blower still runs.
Since you are getting a normal heat cycle.....the limits are ok. Any open limit will not allow the burner to light.
If you look at the board.... I highlighted the fan control area. This board shuts the blower off after a heat cycle by timer. It would appear that board may be at fault. This is assuming the stat is not in the FAN ON mode. You could remove the stat and see if blower still runs.
#5
01-18-17, 11:28 AM
Unfortunately the stat's fan control is set to "auto" so should only engage when the stat trips the HVAC to heat (or cool).
Thank you for the picture, that always helps. It does look similar to mine.
I tried turning off the stat and then removing it after one of the heat cycles (steps 1-5 mentioned previously). The blower just continues to run.
I guess I am going to start searching to see if I can find a replacement board. I will keep you up to date on any additional progress I make.
Is there anything else I can check to give me a guarantee that the board is bad?
Thank you for the picture, that always helps. It does look similar to mine.
I tried turning off the stat and then removing it after one of the heat cycles (steps 1-5 mentioned previously). The blower just continues to run.
I guess I am going to start searching to see if I can find a replacement board. I will keep you up to date on any additional progress I make.
Is there anything else I can check to give me a guarantee that the board is bad?
#6
01-18-17, 11:39 AM
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 12,667
Received 39 Upvotes
on
37 Posts
Just to eliminate a bad thermostat wire, remove the wires from the terminal strip leaving only R & W in place. This will allow you to create a call for heat from the stat but remove any possible outside cause for the fan running.
#7
01-18-17, 11:50 AM
Yellow LED rapid flashing means "unexpected flame". The board thinks there is flame when there shouldn't be. Check the flame sensor.
#8
01-18-17, 11:51 AM
Thank you! I am going to try both of those tonight. I was really hoping for a cheap part (a limit switch or pressure vent switch or something of that nature), maybe I am in luck?
In the mean time I believe did find my replacement board on Amazon based on my model and serial number.
Model: RGRA-10EZAJS
Serial: DF5D707 F4494 4584
I will report back soon with an update. Thank you all for your help so far, it is very much appreciated!
In the mean time I believe did find my replacement board on Amazon based on my model and serial number.
Model: RGRA-10EZAJS
Serial: DF5D707 F4494 4584
I will report back soon with an update. Thank you all for your help so far, it is very much appreciated!
#9
01-18-17, 03:39 PM
I checked the sensor and cleaned it (its a PITA to get to, you have to remove the burner assembly and those screws are tucked tight into the corners!). This did not help (unfortunately).
As @PJmax stated at this point everything seems to point to a faulty board. I also read the reviews of the replacement board and many of those purchasers mentioned the exact same issue that I am currently experiencing.
I will update the thread again after I install the board.
Thanks again for everyone's help, it is much appreciated!
As @PJmax stated at this point everything seems to point to a faulty board. I also read the reviews of the replacement board and many of those purchasers mentioned the exact same issue that I am currently experiencing.
I will update the thread again after I install the board.
Thanks again for everyone's help, it is much appreciated!
#10
01-18-17, 03:44 PM
Group Moderator
skaggsje.... I believe he was getting the flashing yellow LED when in heat mode and burner on.
Nothing wrong with the sensor although a good cleaning is routine maintenance.
The idea of the yellow LED is when the burner is firing..... you want the yellow LED to be on as much as possible. A fast flicker is good. An occasional flicker would be bad.
Nothing wrong with the sensor although a good cleaning is routine maintenance.
The idea of the yellow LED is when the burner is firing..... you want the yellow LED to be on as much as possible. A fast flicker is good. An occasional flicker would be bad.
#11
01-18-17, 05:55 PM
Just to clarify: The flashing yellow/amber light would be on in heat mode but would stay on after the burners would go off (once the stat reads room temp and desired temp match or is turned off) and the blower would continue to blow. I set a timer and it reached about 15 minutes of blower on + flashing yellow/amber light with no burner activity before I manually shut it down by cutting the power. So step 5 that I had described in my 2nd post add the flashing yellow/amber light.
#13
01-27-17, 02:44 AM
If you are looking for a replacement board and have the same model and direct vent type furnace look at this board instead: ICM Controls ICM288 of the other one mentioned in the post. The previous product link is actually exactly this board but marked up more with a different (wrong) image depiction and description. This was the board sent to me when I ordered it.
I did end up returning it and installing the ICM288 instead. Everything works great!
Thanks again to everyone for their help!
I did end up returning it and installing the ICM288 instead. Everything works great!
Thanks again to everyone for their help!
