What does a pressure switch do?

[Andy H]

The auger on my forester pellet stove stopped working so I called the united states stove company's 800 number. The guy told me that on that stove when the auger stops working it usually is because of a bad pressure switch and then he said I could just bypass it to check it out; so that is what I did.

Sure enough it started working. I let it run for about 20 minutes and then called him back and they are going to send another one out. The day before the auger stopped working I noticed that the front glass was turning completely black with soot. Not sure if this had anything to do with it. I was using the same brand of pellets and all the settings were the same.



Btw- I'm not a person that complains a lot but we got this stove in October and it's been complete junk ever since. I guess it's my fault because we didn't have any feedback on the thing before we bought it. The thing was a new model so there was nothing really out there. We got it because of it's small size and the area we could put it in would not work with a large stove.

The thing only starts about half the time so I have to use a torch with mapp gas to get it going, you have to keep messing with the air adjustment which is totally fine but the way the stove is set up you have to take the whole side cover off to do that. The fire brick backing cracked so I ordered a new one and that cracked about 3 days later so we are just using it like that. Sometimes the thing will get burning hot and sometimes it feels like it's not putting out half the heat it should be .... and this is all with the same brand of pellets and all he settings the same.


Not really sure what I can do though. It's under warranty so I'm getting the parts for free but not for much longer. I have a feeling it's just going to get worse and worse with this stove. Not sure if I just got a lemon or if they are all this bad.


Here is the stove I'm talking about


http://www.usstove.com/proddetail.php?prod=5824


Does anybody else here own this? I love to hear if you're having the same issues.

 

[Fsappo]

It may be something that monitors a door or hopper being open. Also, your buying a complicated piece of equipment from a source that sells whatever is the cheapest they can get their hands on. USSC makes cheap stuff. Thats why you wont see it in a true fireplace shop. With their wood stoves and furnaces, cheap can be fine. But on something like a pellet stove, you buy a USSC stove or an Englader if you want value and you dont mind fixing up stuff on your own with the help of some tech support.

 

[Andy H]

So would bypassing it have a negative effect on the stove while it's running?

 

[Fsappo]

I need to learn to read more and think before posting.

 

[Andy H]

The stove is a Forester 5824

I wasn't getting an error code at all. The auger just didn't work. I bypassed the switch by connecting the two wires that hook to it together. It seems to be working ok now but now the glass is turning black in about 5 minutes. it's a pretty thick ash.

 

[Fsappo]

Did you claim this already on your taxes for the 30% federal rebate?

 

[Andy H]

Not yet

 

[Fsappo]

I'm wondering if you could just sell that thing off, buy a decent stove from a real fireplace store and claim both of them on your taxes. It may make it so you can get something better quality for not too much more money

 

[Andy H]

This is the stove. It may give you an idea of why we needed something small. It's really the only spot in the whole house where we had room for a pellet stove.

I'd love something bigger but we just don't have room for it. And even if we did get something that would fit like the Envirofire Mini I'm betting it the vent would not line up at all and i'd have to cut another hole in the side of my house/siding


but If i have to keep dealing with this pile of crap stove that may be what I end up doing.

 

[LI-Mini-Owner]

So would bypassing it have a negative effect on the stove while it's running?

If the switch is defective, then bypassing it while you run out and get a replacement is fine, but the black smoke you describe could mean that the switch is doing it's job and shutting down the auger because of lack of vacuum.

To test the Vacuum switch, leave the switch bypassed, and connect the switch leads to a DMM set on the lowest Ohm scale. With stove running it should read a closed circuit (<10 ohms or so). Now shut the stove down, and when the exhaust blower stops the DMM should change to an open circuit. From your description I suspect that closed circuit test will fail.

The final test of the switch would be to disconnect the hose from the stove, and draw slight vacuum with your mouth. The DMM should go to a <10ohm reading. If that passes, then you have a lack of vacuum that needs to be addressed.

Lastly - My vacuum switch switch has 3 lugs... A common, and normally open, and a normally closed. If this stove never worked at all, then perhaps the factory never wired to the switch correctly. on my Enviro Mini you need to connect to the Common and Normally Open.


I presume the stove has a slide damper... is it at least open half way?

 

[Andy H]

thank you, I'll do some testing on it tonight.

it does have a slide damper that is opened about 20% if I open it any more than that the pellets fly out of the burn pot as soon as they drop down in.

 

[LI-Mini-Owner]

Well if you can get pellets flying by opening the damper way up, then it sounds like you should have good vacuum being produced, and no major air leaks into the combustion box.

Good luck.

 

[bjr23]

You talk about some sooting, I'm wondering if the vacuum switch just got plugged. Anyway just check to make sure orifice and hose are clear. bjr23

 

[SmokeyTheBear]

Andy, how long have you had the stove?

Would you describe the venting system?

 

[SmokeyTheBear]

The stove is a Forester 5824

I wasn't getting an error code at all. The auger just didn't work. I bypassed the switch by connecting the two wires that hook to it together. It seems to be working ok now but now the glass is turning black in about 5 minutes. it's a pretty thick ash.

bypassed vac switch allows the auger to operate indicates bad vac switch or connecting hoses
soot is result from lack of combustion air from plugged intake or exhaust or combustion air setting on stove...i think

If his exhaust is plugged or his intake is plugged likely the vacuum switch is going to say yikes and shut the stove down. And yes they also can and do lead to soot.

 

[Andy H]

here is the vent

I just cleaned it a couple weeks ago and there was not even that much in it.


This is my first winter with the stove and I only run it about 8 or so hours a day. Is it possible that I got one bag of pellets that is bad? Maybe high moisture or something?

 

[SmokeyTheBear]

How many bags have you gone through if it is 50 or more you also need to get at the combustion blower cavity and I can't tell from picture here but there has to be a rise in that horizontal section of pipe or else it will fill that section with soot.

How did you go about cleaning it, this matters because you can actually cause soot to get packed into other areas of the stove while thinking you are getting things nice and spotless.

The reason I'm asking is that both the vacuum trip and soot are pointing to possibly the same cause, dirty stove syndrome.

 

[Andy H]

ok, you're saying the 1 foot section that goes through the wall needs to have a rise in it? If so how much? I'm pretty sure right now it's perfectly level.


when i cleaned it i just took all the pipes apart and cleaned them individually with a wire brush. the pieces are just interlocked together, no sealant or screws so it's super easy to do.


and I would guess I have burned right around 50 bags, maybe a little more.

 

[SmokeyTheBear]

There's only one foot of horizontal run there?

Damn that's very short I'd have guessed at least two feet looking at the wall and the fact the stove is away from the wall. The rise is supposed to be 1/4 in per foot.

I'd look at the combustion motor cavity, the blades on the combustion fan, and from the combustion fan cavity back into the heat exchanger. Make sure you have a gasket on hand before removing that blower.

I'll assume for the time being that the other areas of the stove have been at least vacuumed well.

When you get done you are going to want to check your flame and make any adjustments via the damper in slow increments.

Blue above the pellets white with a yellow tinge above that, the pellets should be wobbling in the burn pot, embers will be ejected as new pellets enter and old one are burned down to almost ash.

Some of the burn pot should still be visible after the stove has settled down.

Do this adjustment on low burn.

 

[rickwa]

sounds like switch is fine your stove needs cleaned, possibly areas that you cant see like comb blower or exhaust passages. it is not the incoming air side of things. if the incoming air side was plugged the stove would have excessive vacuum and hold switch closed. your comb fan probably needs cleaned

 

[rickwa]

after looking at the manual online if i were you i would start with removing and cleaning the combustion blower

 

[Andy H]

Ok, I messed with the stove for a couple hours last night and figured I'd give an update.


I removed the vent pipes again and did another cleaning. It wasn't bad at all but I just wanted to make sure. Then I removed the exhaust motor and that all looked pretty clean

I kept trying to start it and was getting the same issues.... a lazy flame and then the glass would turn black and the stove would not put out a lot of heat.


I decided to remove the fire bricks and give it a good cleaning inside even though i've done that every week since I got it

that is when I saw it, there are two vents at the very top of the inside of the stove, they are very hard to see unless you get right in the stove... I didn't even see these in the manual. Anyways, they were packed full of ash. I stuck my vacuum in there and sucked them clean.

Fired up the stove and it ran perfect, I even hooked the pressure switch back up and that works.


I feel bad, I was talking bad about the stove but it was my fault, I should have noticed those vents were plugged. In fact, I think they have been plugged for a while because Last night after it was cleaned I could not believe the amount of heat it was putting out.



The glass is still stained with a brown tint that I can't seem to remove, does anybody know of anything that will work to remove that?

 

[SmokeyTheBear]

Ceramic stove top glass cleaner, a moistened cloth dipped in ashes and elbow grease, and so forth. There was a large thread on glass cleaning not that long ago. Search on windex , glass cleaning, glass cleaner. Remember to have the stove off and the glass cold.

 

[LI-Mini-Owner]

Glad to hear you're pumping out the heat again. So these sound like vents in the exhaust path somewhere that were clogged, preventing the firebox from pulling a sufficient vacuum. Nice job.

 

[bjr23]

If all else fails, scrape with a razor blade carefully, then glass cleaner. bjr23