Blower Turns Off With Gas
#1
12-23-18, 10:41 AM
Blower Turns Off With Gas
Hello,
I recently started having intermittent problems with my furnace and want to run them past the forum before calling someone out during the holiday. I have a Nest 3rd Gen with a York Deluxe Diamond 80 Furnace controlled by a White-Rodgers 50A51-242. Here is what has started happening:
1) Igniter warms up, burners kick on burn for 1.5 minutes and then turn off.
2) Blower kicks on after gas turns off and runs for about 10 minutes and then turns off.
Cycle Repeats
Wiring
Thermostat->Furnace
C -> B
* -> Humidifier Solenoid (Other side of humidifier goes to B on the Furnace)
Rh -> R
W1 -> W1
Y1 -> Y
G -> G
I recently started having intermittent problems with my furnace and want to run them past the forum before calling someone out during the holiday. I have a Nest 3rd Gen with a York Deluxe Diamond 80 Furnace controlled by a White-Rodgers 50A51-242. Here is what has started happening:
1) Igniter warms up, burners kick on burn for 1.5 minutes and then turn off.
2) Blower kicks on after gas turns off and runs for about 10 minutes and then turns off.
Cycle Repeats
Wiring
Thermostat->Furnace
C -> B
* -> Humidifier Solenoid (Other side of humidifier goes to B on the Furnace)
Rh -> R
W1 -> W1
Y1 -> Y
G -> G
Last edited by speemike; 12-23-18 at 10:53 AM. Reason: Add Furnace Wiring
#2
12-23-18, 10:48 AM
Group Moderator
There is a diagnostic fault light on that board. The fault codes are listed directly on the board.
Sounds like the furnace may be overheating,
Sounds like the furnace may be overheating,
#3
12-23-18, 11:14 AM
Hi Pete,
Thanks so much for the quick reply. I just opened the furnace up and the little red light on the board is not blinking. I also closed the switch for the panel to make sure the board was getting power, still no blinking light. But the furnace seems to be working fine, right now. The problem is definitely intermittent.
Thanks so much for the quick reply. I just opened the furnace up and the little red light on the board is not blinking. I also closed the switch for the panel to make sure the board was getting power, still no blinking light. But the furnace seems to be working fine, right now. The problem is definitely intermittent.
#4
12-23-18, 07:23 PM
Member
remove the nest thermostat from the wall and jump R and W - see if it functions normally.
with normal overheating, blower continuous to run, burners turn off.
with normal overheating, blower continuous to run, burners turn off.
#6
12-25-18, 10:13 PM
Watch
So the problem seems to be pretty consistent now. It is almost like it is programmed to run that way. It seems like something is telling it to turn the gas off when the blower is on and the shut the blower off and turn the gas on. Can anyone help verify the wiring is correct in the original post? Is there some kind of setting in the Nest which might’ve causing this? Thanks so much for the feedback.
#7
12-25-18, 10:37 PM
Member
The Nest stats are really low end junk and have been known to cause all sorts of bizarre issues. If you removed the stat from the equation and jumped R-W, and the unit ran fine, then yet another Nest thermostat is headed to the trash.
#8
12-25-18, 10:57 PM
Roughneck
Thanks roughneck! I am curious which thermostat you would recommend? I am going to still mess with it some more, as I have to much investeded into the network to just pitch it. I guess I should have done some more research.
#9
12-26-18, 11:19 AM
High Limit Switch
I rechecked all for the wiring per NEST and the furnace wiring diagram, it all checks out. I ran the furnace with the bottom cover off and I am getting an error light. It 4 blinks which indicates the high limit switch. Here is what happens:
1) Burners come on until the high limit switch triggers. Burners turn off and Error light starts flashing, 4 flashes.
2) Blower kicks on and runs for around 5 minutes.
3) While the blower is running the igniter starts glowing, as soon as the gas kicks on the blower turns off.
I pulled the limit switch out and checked it, it is good.
Super frustrating.
1) Burners come on until the high limit switch triggers. Burners turn off and Error light starts flashing, 4 flashes.
2) Blower kicks on and runs for around 5 minutes.
3) While the blower is running the igniter starts glowing, as soon as the gas kicks on the blower turns off.
I pulled the limit switch out and checked it, it is good.
Super frustrating.
#11
12-26-18, 11:45 AM
Blower
The blower starts and runs fine, but only when the gas is off. They will not run together. Which makes sence why the limit switch is getting too hot, because no air is blowing over it when the burners are on.
#12
12-26-18, 12:07 PM
Volt Meter
So maybe the board tells the burners to kick on but is failing to turn on the blower. The burners keep going until the limit switch kicks them off because it gets to hot. Then to recover from this high temp the board turns the blower on to cool it down. Once the limit switch cools down the board tries to run the cycle again. I am going to try and clean off the temp sensor, try to measure the voltage to the blower, and then probably try to call someone in. I am stumped.
#13
12-26-18, 12:18 PM
Group Moderator
Ok...... shorting the R to W makes the furnace run fine. That indicates a defective nest sub base. They will send a replacement no charge.
Yes.... when the system is in overheat...... the blower is on and the gas is off. That is by design. You need to find out why your furnace is overheating. Make sure registers are open. Make sure returns aren't blocked. I believe you changed the filter. You may have a lint clogged evaporator coil in the furnace.
Yes.... when the system is in overheat...... the blower is on and the gas is off. That is by design. You need to find out why your furnace is overheating. Make sure registers are open. Make sure returns aren't blocked. I believe you changed the filter. You may have a lint clogged evaporator coil in the furnace.
#14
12-26-18, 02:15 PM
PJ Max
Thanks PJMax,
Intersting comment regarding the NEST base. I noticed some continuity between the terminals when I was trying to figure out what was going on. I ended up taking all the wires out of the base because it kept showing voltage on temanals that should not have had voltage. I though maybe I had a short in the wires, must have a crappy base.
I wonder if the base is causing the problem.
In terms of the filter, it is a washable filter and it was pretty dirty. I ended up completely removing the filter while I have been diagnosing the problem. I even opened the filter door and left it open to see if the problem persisted. It did.
Intersting comment regarding the NEST base. I noticed some continuity between the terminals when I was trying to figure out what was going on. I ended up taking all the wires out of the base because it kept showing voltage on temanals that should not have had voltage. I though maybe I had a short in the wires, must have a crappy base.
I wonder if the base is causing the problem.
In terms of the filter, it is a washable filter and it was pretty dirty. I ended up completely removing the filter while I have been diagnosing the problem. I even opened the filter door and left it open to see if the problem persisted. It did.
#18
12-28-18, 06:24 AM
Nope
There is no link between the two. I am pretty sure I am close to having it figured out. For some reason the blower is not kicking on with the heat call. So the burners heat up to the point that the high limit switch shuts them off. Then there must be some safety mechanism that can kick the blower on to cool the system down. The the cycle repeats.
Does anyone know what should trigger the blower to turn on after the burners come on? Is it a temp switch or a time delay, or is it just controlled by the board?
Does anyone know what should trigger the blower to turn on after the burners come on? Is it a temp switch or a time delay, or is it just controlled by the board?
#19
12-28-18, 06:28 AM
Blower
Also, the blower seems to be working just fine and without any signs of humming. The blower turns on after I trigger the high limit switch and if I turn it on through the thermostat.
#20
12-28-18, 05:37 PM
Update
I finally called a guy out. He initially thought it was the capacitor and the blower. But then I showed him how the board just shuts the blower down mid cycle. He seems to think the problem is most likely the board. If I can upload a video I will, it shows how it was cycling.
