NPS40 help

[ambene]

Hi All, I'm a pellet newbie although have spent the last week searching the internet on Napoleon troubleshooting and interestingly enough, I'm always led back to this site.

If anyone has any suggestions to help with my issue, I'd sure appreciate them. I have a Napoleon NPS40 pellet stove, which I have just loved using. I downloaded the pellet stove manual (I'm a new home-owner and the stove came with) to figure out what I've run into.

My stove doesn't ignite (the ignitor doesn't glow red/orange) and the blower on the left (exhaust blower) blows constantly. I've taken it apart and cleaned it but to no avail.

Anyone have any ideas? I've checked to make sure the 200 degree reset button is fine, I've depressed it as much as seems reasonable but don't want to break it. It's popped out about 1/8-1/4 of an inch and I've pushed on it with about 40lbs of force (more force than I tamp my espresso grind with) but it didn't depress.

Thank you anyone for any assistance!

 

[imacman]

First of all, welcome to the forum.

By this statement, "I have a Napoleon NPS40 pellet stove, which I have just loved using.", I guess we're to assume that the stove DID start and burn properly at one time?

Did you go through each step in the troubleshooting guide at the back of the manual under this section?

"The ignitor will not
light the pellets
however everything
else in the
heater operates"

 

[smwilliamson]

bad high limit switch

 

[ambene]

First of all, welcome to the forum.

By this statement, "I have a Napoleon NPS40 pellet stove, which I have just loved using.", I guess we're to assume that the stove DID start and burn properly at one time?

Did you go through each step in the troubleshooting guide at the back of the manual under this section?

"The ignitor will not
light the pellets
however everything
else in the
heater operates"

Hello, I sure did - I downloaded the manual and went through all troubleshooting steps and looked through the internet to see if there were any others with similar issues. There isn't much that supports troubleshooting the exhaust fan, more information surrounding the convection blower.

 

[arnash]

There isn't much that supports troubleshooting the exhaust fan, more information surrounding the convection blower.

I guess you've missed all that's been written in the last month about combustion blowers (tons!). You complain that the blower runs constantly, but why would you think that that is not normal, it has to run constantly to exhaust the fumes and feed air to the fire? As for the ignitor, they have a limited life-span, but can be not doing their job if they're not close enough to the pellets. Also, they aren't the only way to light a fire nor the fastest (my stove was made before they were invented so manual ignition is how I roll, it's how to get instant heat).

 

[ambene]

There isn't much that supports troubleshooting the exhaust fan, more information surrounding the convection blower.

I guess you've missed all that's been written in the last month about combustion blowers (tons!). You complain that the blower runs constantly, but why would you think that that is not normal, it has to run constantly to exhaust the fumes and feed air to the fire?

Well.....I guess I have missed the tons about combustion blowers because I have been searching for exhaust fan troubleshooting. I have used the pellet heater many many times and it's not normal for the exhaust fan to run constantly. The fan starts up when the start button is pushed and the stove is cool - that is normal behavior. Presently the exhaust fan blows constantly; as soon as the pellet stove is plugged in. The only possible way to turn it off is to unplug it. The stove has not been used for a week so there is no heat or smoke to exhaust/cool down.

 

[ambene]

bad high limit switch

I'm thinking you're right, but would it be the bad high limit switch or the 160 degree sensor? Is this because the high limit thinks that the stove is still hot, hence the constant fan? If so, then what is the point of the 160 sensor, it seems that it should action before the high limit (200 degree) sensor....

 

[ambene]

There isn't much that supports troubleshooting the exhaust fan, more information surrounding the convection blower.

I guess you've missed all that's been written in the last month about combustion blowers (tons!). You complain that the blower runs constantly, but why would you think that that is not normal, it has to run constantly to exhaust the fumes and feed air to the fire?

Well.....I guess I have missed the tons about combustion blowers because I have been searching for exhaust fan troubleshooting. I have used the pellet heater many many times and it's not normal for the exhaust fan to run constantly. The fan starts up when the start button is pushed and the stove is cool - that is normal behavior. Presently the exhaust fan blows constantly; as soon as the pellet stove is plugged in. The only possible way to turn it off is to unplug it. The stove has not been used for a week so there is no heat or smoke to exhaust/cool down.

EDIT:

Well I've spent the whole morning researching combustion blowers and really only found the one post on this forum that didn't follow up with their solution. Thanks for pointing out combustion blowers, but I didn't see much information pointing to the issue there either.

 

[SmokeyTheBear]

ambene,

Welcome to the forum.

Did you try manually lighting the stove?

 

[ambene]

ambene,

Welcome to the forum.

Did you try manually lighting the stove?

Hi Smokey the Bear, thank you for the welcome -- lots of info here!

No I didn't manually light the stove. Of course I could and get heat out, but I'm really for fixing the problem. I've just removed the high limit switch and plugged the stove back in -- exhaust fan still running. I've cleaned the stove top to bottom and disconnected/reconnected every switch & connection that is related to the high limit or 160 degree switch.

Is the suggestion to manually light the stove specific to just making it run or will it help troubleshoot this continuous exhaust fan issue? I will probably end up just lighting it anyway but I had hoped to fix it myself.

 

[SmokeyTheBear]

ambene,

Welcome to the forum.

Did you try manually lighting the stove?

Hi Smokey the Bear, thank you for the welcome -- lots of info here!

No I didn't manually light the stove. Of course I could and get heat out, but I'm really for fixing the problem. I've just removed the high limit switch and plugged the stove back in -- exhaust fan still running. I've cleaned the stove top to bottom and disconnected/reconnected every switch & connection that is related to the high limit or 160 degree switch.

Is the suggestion to manually light the stove specific to just making it run or will it help troubleshoot this continuous exhaust fan issue? I will probably end up just lighting it anyway but I had hoped to fix it myself.

No I just wanted to know if you had the stove generate some heat and then turn it off an see if the exhaust fan shuts down (the exhaust fan is the combustion fan), the other fan is the convection fan (room blower, distribution blower) that sends the heated air into the room.

If the stove is on the exhaust blower should be running, after the stove gets to temperature the convection blower turns on.

The normal issue is with the low limit (proof of fire) snap disc sticking on causing the convection blower to run all the time the stove is on or the controller thinking there is a fire and keeping the convection fan on all the time (sometimes with the stove turn off but still plugged in).

If you can fire the stove then the high limit switch isn't your problem.

 

[ambene]

ambene,

Welcome to the forum.

Did you try manually lighting the stove?

Hi Smokey the Bear, thank you for the welcome -- lots of info here!

No I didn't manually light the stove. Of course I could and get heat out, but I'm really for fixing the problem. I've just removed the high limit switch and plugged the stove back in -- exhaust fan still running. I've cleaned the stove top to bottom and disconnected/reconnected every switch & connection that is related to the high limit or 160 degree switch.

Is the suggestion to manually light the stove specific to just making it run or will it help troubleshoot this continuous exhaust fan issue? I will probably end up just lighting it anyway but I had hoped to fix it myself.

No I just wanted to know if you had the stove generate some heat and then turn it off an see if the exhaust fan shuts down (the exhaust fan is the combustion fan), the other fan is the convection fan (room blower, distribution blower) that sends the heated air into the room.

If the stove is on the exhaust blower should be running, after the stove gets to temperature the convection blower turns on.

The normal issue is with the low limit (proof of fire) snap disc sticking on causing the convection blower to run all the time the stove is on or the controller thinking there is a fire and keeping the convection fan on all the time (sometimes with the stove turn off but still plugged in).

If you can fire the stove then the high limit switch isn't your problem.

Perfect, thank you for the information then I shall re-assemble and give it a whirl. To quote Arnold -- "I'll be back".

 

[ambene]

ambene,

Welcome to the forum.

Did you try manually lighting the stove?

Hi Smokey the Bear, thank you for the welcome -- lots of info here!

No I didn't manually light the stove. Of course I could and get heat out, but I'm really for fixing the problem. I've just removed the high limit switch and plugged the stove back in -- exhaust fan still running. I've cleaned the stove top to bottom and disconnected/reconnected every switch & connection that is related to the high limit or 160 degree switch.

Is the suggestion to manually light the stove specific to just making it run or will it help troubleshoot this continuous exhaust fan issue? I will probably end up just lighting it anyway but I had hoped to fix it myself.

No I just wanted to know if you had the stove generate some heat and then turn it off an see if the exhaust fan shuts down (the exhaust fan is the combustion fan), the other fan is the convection fan (room blower, distribution blower) that sends the heated air into the room.

If the stove is on the exhaust blower should be running, after the stove gets to temperature the convection blower turns on.

The normal issue is with the low limit (proof of fire) snap disc sticking on causing the convection blower to run all the time the stove is on or the controller thinking there is a fire and keeping the convection fan on all the time (sometimes with the stove turn off but still plugged in).

If you can fire the stove then the high limit switch isn't your problem.

Perfect, thank you for the information then I shall re-assemble and give it a whirl. To quote Arnold -- "I'll be back".

The stove is running like a champ (through a manual start with gel fuel) everything going and making the usual noises - exhaust fan, convection fan and auger. I'll get warm and then shut down the stove and let it cool down - hopefully the issue is just a stuck 160 sensor.

 

[arnash]

I predict it will shut down normally. A few days ago I banged on my worn door latching rod to try to bend it backward a hair, (didn't work) when all of a suddenly the combustion blower turned on by itself. I switched-off the power strip the stove is plugged into, and turned it back on and the stove turned back on also. I left it switched off and the next day, after a day of use, it shut itself down normally. I think yours will reset itself also.

And I'm afraid you're right about the difficulty of finding all there is to find about any given subject using the search function. Many threads develop tangent subject-matter that isn't mentioned in the title (and many titles are pathetically limited in details about the subject issue).

 

[SmokeyTheBear]

To search the content of the threads you use the top search bar or even better the advanced search.

ambene,

How are things going?

 

[ambene]

To search the content of the threads you use the top search bar or even better the advanced search.

ambene,

How are things going?

Hi Smokey,

The stove ran very well all last night and I shut it off at about 8:30am ET (~2 hours ago). The fan is still running so far so I'll give it a couple more hours and then will manually start the fire again. I took out the high limit switch yesterday and the fan still ran when I tested (and then I put it back) so I'm guessing the problem must be that 160 degree switch which is stuck or has some issue.

Arnash posted right before you that his ran 24 hours and then shut off by itself so I can give that a try too.

 

[save$]

I have that same stove, I am not familiar with the problem solving for switches etc. But it seems you are getting some very knowledgeable advise, esp. from this forum's good friend, Smokey.
What I will contribute is that when you have turned that top switch to "click" off, that my stove will be silent in 15 mins. every time.
One other issue with the lighting. There were a lot of those stoves sold in 2008 that needed the igniter hole in the burn pot drilled out a little larger. That solved a lot of starting issue where the igniter was not faulty. Also, if yours has that ring that sat on top of the burn pot, you might want to take it off. Napoleon stopped making those and informed me that they found they interfered with the burning.
So far, with good cleaning from the advice on this forum, I've managed to stay problem free and to have a compfortably heated home at a more reasonalbe price than I would have had if I continued to heat with oil.

 

[ambene]

I have that same stove, I am not familiar with the problem solving for switches etc. But it seems you are getting some very knowledgeable advise, esp. from this forum's good friend, Smokey.
What I will contribute is that when you have turned that top switch to "click" off, that my stove will be silent in 15 mins. every time.
One other issue with the lighting. There were a lot of those stoves sold in 2008 that needed the igniter hole in the burn pot drilled out a little larger. That solved a lot of starting issue where the igniter was not faulty. Also, if yours has that ring that sat on top of the burn pot, you might want to take it off. Napoleon stopped making those and informed me that they found they interfered with the burning.
So far, with good cleaning from the advice on this forum, I've managed to stay problem free and to have a compfortably heated home at a more reasonalbe price than I would have had if I continued to heat with oil.

Hi and thanks for your comments, that was my experience too previously - that when I turned the auger feed & convection blower off in ~15 min the stove would be silent. This is not the case now so I'll keep on troubleshooting.

The information has been great and the support too - I am very very appreciative.

 

[SmokeyTheBear]

ambene,

Well we've eliminated one of the for snap discs on the stove, you seem to feel it is the 160 degree blower override, can I ask why you feel that?

You are there and the only information we get is what you tell us.

If you are up to it we can test the 140 and 160 degree switches provided you have a multimeter or a continuity measuring/indicating device device and lighter or candle.

 

[ambene]

ambene,

Well we've eliminated one of the for snap discs on the stove, you seem to feel it is the 160 degree blower override, can I ask why you feel that?

You are there and the only information we get is what you tell us.

If you are up to it we can test the 140 and 160 degree switches provided you have a multimeter or a continuity measuring/indicating device device and lighter or candle.

Sure thing! I just happen to have a multi-meter just waiting for the opportunity to be used. The reason I think (uneducated guess) it's the 160 degree module is because the problem is there and that's the closest electric measurement to the problem. Now unfortunately I have an appointment where I will have to leave for about 5 hours (1 hour drive one-way plus lovely traffic on the way back) so I can either attempt to test the switches when I return or whenever is most convenient for any guidance you would be willing to offer (and taking your schedule into consideration). If you would write instructions, I will follow them asap.

Thank you!

 

[SmokeyTheBear]

When you get back is fine.

With the stove off, cold, and unplugged:

Lift one of the wires off of the 160 degree convection fan override snap disc, using a multimeter on any of its resistance ranges, measure the resistance across the two switch tabs, if the resistance is infinite that switch is likely fine and we won't remove it for further testing and you can put the wire you removed back on to the switch tab it came from.

Repeat the same process for the 140 degree snap disc. Post to let us know what you found.

If either switch measures close to zero ohms, tap it and see if it then reads infinite (flaky switch, but this a problem switch, we will give it a bit of further testing with a flame). This switch will be the one that is causing trouble. While it is possible both switches are bad it isn't likely. It is also possible that both switches are good and the problem is elsewhere.

The 120 igniter switch I haven't really looked at yet but don't expect that to present this kind of a problem.

I'll also want to know if these switches are ceramic or bakelite (aka plastic).

I'd say have fun on your outing but from your description it doesn't sound like something that would be fun.

 

[ambene]

When you get back is fine.

With the stove off, cold, and unplugged:

Lift one of the wires off of the 160 degree convection fan override snap disc, using a multimeter on any of its resistance ranges, measure the resistance across the two switch tabs, if the resistance is infinite that switch is likely fine and we won't remove it for further testing and you can put the wire you removed back on to the switch tab it came from.

Repeat the same process for the 140 degree snap disc. Post to let us know what you found.

If either switch measures close to zero ohms, tap it and see if it then reads infinite (flaky switch, but this a problem switch, we will give it a bit of further testing with a flame). This switch will be the one that is causing trouble. While it is possible both switches are bad it isn't likely. It is also possible that both switches are good and the problem is elsewhere.

The 120 igniter switch I haven't really looked at yet but don't expect that to present this kind of a problem.

I'll also want to know if these switches are ceramic or bakelite (aka plastic).

I'd say have fun on your outing but from your description it doesn't sound like something that would be fun.

Hi Smokey thanks for the instructions - I'm just back and I have a class which is fun however traffic along 95 any time after 3pm is not so fun. I will follow your instructions first thing in the morning and report back. Thank you for your help!!

 

[ambene]

When you get back is fine.

With the stove off, cold, and unplugged:

Lift one of the wires off of the 160 degree convection fan override snap disc, using a multimeter on any of its resistance ranges, measure the resistance across the two switch tabs, if the resistance is infinite that switch is likely fine and we won't remove it for further testing and you can put the wire you removed back on to the switch tab it came from.

Repeat the same process for the 140 degree snap disc. Post to let us know what you found.

If either switch measures close to zero ohms, tap it and see if it then reads infinite (flaky switch, but this a problem switch, we will give it a bit of further testing with a flame). This switch will be the one that is causing trouble. While it is possible both switches are bad it isn't likely. It is also possible that both switches are good and the problem is elsewhere.

The 120 igniter switch I haven't really looked at yet but don't expect that to present this kind of a problem.

I'll also want to know if these switches are ceramic or bakelite (aka plastic).

I'd say have fun on your outing but from your description it doesn't sound like something that would be fun.

I applied the multimeter to the 160 switch (I had to figure out how to use the thing) and it shows multiple readings when I apply the leads but always returns to zero.

I applied the leads to the metal rivets on the switch represented in the attached photo - it's all plastic and the pic looks exactly the same as on my stove.

 

[SmokeyTheBear]

ambene,

If you have some electrical tape around we can further verify that is the problem.

That 160 degree snap disc that is showing up as always closed can be removed from the circuit by placing electrical tape on the lead you removed to do the continuity test and the stove manually fired at a low heat level setting, allowing the stove to come to temperature the blowers and auger should operate and then turning the stove off.

It should proceed to normal shut down.

Did you also do the test with the 140 degree snap disc?

 

[ambene]

ambene,

If you have some electrical tape around we can further verify that is the problem.

That 160 degree snap disc that is showing up as always closed can be removed from the circuit by placing electrical tape on the lead you removed to do the continuity test and the stove manually fired at a low heat level setting, allowing the stove to come to temperature the blowers and auger should operate and then turning the stove off.

It should proceed to normal shut down.

Did you also do the test with the 140 degree snap disc?

I did not do the test with the 140 but I will now. A question, if I remove the 160 disc completely from a cold stove, shouldn't the stove shut off?