# Blower will not shut off.



## lj4 (Nov 25, 2006)

Hi, I have a Snyder General Corporation Model # GUG070A012N furnace.

The problem is that the blower doesn't shut off unless I turn power off to the unit. After reading some of the other threads, I removed the fan and limit switch and turned the dial until it clicked but the fan continued to run.

What should I try next?


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## acefurnacefixer (Nov 24, 2006)

If you dont mind messing with high voltage, turn the power off and replace the fan/limit control.


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## lj4 (Nov 25, 2006)

acefurnacefixer said:


> If you dont mind messing with high voltage, turn the power off and replace the fan/limit control.


How do I know for sure that it is the fan/limit control?


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## acefurnacefixer (Nov 24, 2006)

Well thats a great question .......I dont, but if you use your volts AC meter you can easily detemine if it is the problem.


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## #CARRIERMAN (Oct 18, 2006)

Hi lj4

Find the side that says fan on the fan limit switch. Remove one of the wires out of it, make sure it does not short against anything. Plug the furnace back in and see if the blower runs, if it doesn't eureka you got it.

Good luck 
Rusty


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## lj4 (Nov 25, 2006)

#CARRIERMAN said:


> Hi lj4
> 
> Find the side that says fan on the fan limit switch. Remove one of the wires out of it, make sure it does not short against anything. Plug the furnace back in and see if the blower runs, if it doesn't eureka you got it.
> 
> ...


I unplugged the wire but the fan still ran.
What can I try next?


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## #CARRIERMAN (Oct 18, 2006)

Hi lj4

Look at your thermostat and make sure that the fan switch is in the auto position. If its not, this is probalbly your problem. If it is in the auto mode you probably have a fan relay stuck. If you shut the power off to your furnace. Remove the blower door, trace the wires back from the blower motor to where they are connected inside the electrical box. You should see a relay with six wires on it. There will be a side that has red and a side that has black. Plug your wire back into the fan/limit switch properly. Remove the black wire from the relay that goes to the blower. Make sure to tape the end of the wire so it doesnt short against anything. Turn the power back on to your furnace and see if the blower runs. If it doesnt you will need to replace the realy, you relay should be a 90340. If you have any further questions let us know.

Good luck 
Rusty


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## wmm (Nov 21, 2011)

*Carrier Furnace will not shutoff blower*

Guys,

I tried posting this earlier but was booted off line. 

First timer with HVAC stuff...patience please.

My furnace would come on do it's job, and on shut down it would restart(or false start) about 5 times for 1 or 2 seconds. This has been going on for awhile, now the fan runs all the time. The only way to shut it down is the switch on the side of the furnace.

It is an old Carrier 5BLP1-2 series 211(i think, the label is very hard to read). 

I tried a new thermostat, still runs all the time. In heat mode and auto: fan runs continuous and burners come on and off to regulate temp. In heat mode and ON: fan seems to blow a little harder and burners come on and go off. 

When I switch the thermostat OFF...it does not shut down.

I read your thread and tried to find a temp control relay or anything to that effect. On the circuit board I found a Black wire labeled HI and Red wire labeled LO. 

I have tried pulling those wires out to trouble shoot different scenarios, but must do that again. That is when i got kicked off the internet.

Hope you all are still watching this thread.


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## how (Feb 26, 2011)

Hey WMM
If pulling your wire got you kicked off the internet, what you are pulling might not be a furnace wire. and please..no web cam follow up.

Hey lj4
Have you checked that the switch on the side of the furnace is really a power switch for the whole furnace and isn't just a summer fan switch.


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## M3 Pete (May 10, 2011)

I'm having this exact problem on a Friday night (of course!)

Will report back tomorrow when I poke around inside the furnace.


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## M3 Pete (May 10, 2011)

I have a Carrier Series 101, Model No. 58GS080-DA, built in 1980. 

Blower would not shut off. I pulled off the lower panel, took off the cover protecting the circuit board, and found what is shown in the attached photo.

I pushed down the safety switch to start the blower, and a quick rap on the relay on the right made it click right off, with a bit of an arc showing through the clear plastic of the relay when the gap opened. 

Hopefully that will do it for a while.


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## Houston204 (Oct 18, 2009)

I doubt that this is a permanent solution. If you are confident that you have isolated the problem, you might start checking the price and availability of that control.


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## harleyrider (Feb 20, 2007)

M3 Pete said:


> I have a Carrier Series 101, Model No. 58GS080-DA, built in 1980.
> 
> Blower would not shut off. I pulled off the lower panel, took off the cover protecting the circuit board, and found what is shown in the attached photo.
> 
> ...


 very common problem with old carriers.....thats why I keep a bunch of them boards in stock.


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## wmm (Nov 21, 2011)

I had to replace my board, almost identical to yours m3. I got it for about $50 and it fixed all my problems, blower not shutting off, false starting etc.

the name to another thread with some pics of mine:

When blower comes on, gas shuts off

it runs much better, gave it good cleaning too, which was much easier than I thought.


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## M3 Pete (May 10, 2011)

Houston204 said:


> I doubt that this is a permanent solution. If you are confident that you have isolated the problem, you might start checking the price and availability of that control.


Maybe not. But I'm choking down the cost of a reroof right now, so any no- cost fix is a bonus right now.


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