Why my Pellet stove take so long for the exhaust fan to cut out after shut down?

[Randy]

Hi, I installed a low limit switch on my pellet stove exhaust fan and the stove takes longer for the fan to cut out after shut down than it did with the original limit switch. original 25 min. now 50 min. Can I change this somehow? Is it the switch or type of switch? Do I need a ceramic switch?Thanks in advance. Randy!!

 

[heat seeker]

Check the numbers on each switch to see if they match. You should see some numbers like: L140-20, or F120-20. That is the temperature of the switch. Most are not adjustable, but there are some that are. Those have adjusting screws visible.

 

[Randy]

Check the numbers on each switch to see if they match. You should see some numbers like: L140-20, or F120-20. That is the temperature of the switch. Most are not adjustable, but there are some that are. Those have adjusting screws visible.

The number is F140 and sorry no screw to adjust. Thanks for the reply

 

[Randy]

It will switch the fan ON at rising temperature (at about 140º F) and will stop the fan when the temperature drops to about 120º F.

 

[heat seeker]

That means the switch contacts close at 140º. Do the old and new switches match numbers?

 

[Randy]

Yes they do

 

[Randy]

How about I space it a fraction from the surface of the blower housing will that cause it to cut out sooner? Thanks!!

 

[heat seeker]

It might, but then it will take longer to start the fan and let the control know there is fire. That could result in the stove shutting down.

I'd leave it as is. My stove takes a long time to cool down, so after I'm sure the fire is out, I pull the wire off the snap disc to stop the fans. Works fine, as long as I remember to put it back. Some day I'll add a switch to make it easier. Some day...

 

[Randy]

It might, but then it will take longer to start the fan and let the control know there is fire. That could result in the stove shutting down.

I'd leave it as is. My stove takes a long time to cool down, so after I'm sure the fire is out, I pull the wire off the snap disc to stop the fans. Works fine, as long as I remember to put it back. Some day I'll add a switch to make it easier. Some day...

That sounds good so what kind of switch? Thanks.....

 

[Randy]

I pulled the wire of the switch and the fan kept going? Why is that? Thanks!!

 

[TStark]

Likely its Reverse Logic for failsafe, any open in the wire or harness or connector keeps the combustion fan running.

 

[heat seeker]

On my stove, removing the wire tells the control that the stove is cooled off, so the fans stop. Your switch closes the contacts at 140º, so I assume it would work the same. Maybe this is not the Proof of Fire switch you're playing with, or your stove uses another switch/method.

I would put a simple toggle switch in series with my snap disc.

P.S. Does your switch have 2 or 3 terminals/wires on it?

 

[Randy]

It has 2 terminals.

I removed both terminals/wires still stayed going.

I connected 2 terminals together still on

I am here now stuck with no stove just a few days before Christmas so someone please help me?

My stove is a Danson Bayview stove

 

[heat seeker]

Have you reset the control? Unplug the stove for a few minutes, and try again.

Will your stove not run now? I didn't see where you said that...

Do you have a multimeter so you can check the new switch out?

 

[Randy]

Thanks and sorry forgot to mention after I removed the wire and replaced it the fan won't cut out so I have to unplug it. When I plug it back in the fan comes on again.

 

[Randy]

It shut down this time but can't install the toggle switch if the stove don't shut down with the wire removed. Any other ideas? Toggle switch the fan motor itself????

 

[TStark]

Certain you connectedmotor to the correct terminal? Some are always hot.

 

[Randy]

Thanks and will try that. Is that why the motor keep running with wire removed from switch. I did install new exhaust motor when I installed the new low limit switch.

 

[Harvey Schneider]

It sounds like you are talking about the convection blower and not the exhaust blower. You can't disable the exhaust blower....ever.
If the low limit switch doesn't stop the convection blower (either open or shorted) you probably miswired the motor when you installed it.
All this talk of reaching in and pulling wires makes me think that you are doing this with power applied. That is a very dangerous thing to do.

 

[Randy]

That is what I am talking about stopping the exhaust motor.

 

[Harvey Schneider]

That is what I am talking about stopping the exhaust motor.

The exhaust blower will typically run until the stove has cooled plus a fixed time set by the controls. If the low limit says the stove is still hot the Exhaust blower must still run. It may not turn off promptly when the low limit is reached.