Whitfield Advantage pellet stove, vacuum switch question..

Hello,

Newbie here . I have this Advantage 2T stand alone pellet stove. It is a 1994 and came with the house we just got.
It was in pretty bad shape, ashes everywhere, vent was plugged up with more ashes, found dead bird along with more ashes in exhaust manifold.. I went through everything (using the internet), cleaned everything up, replaced door gasket, replaced exhaust motor seal, oiled the motors as per instruction, cleaned auger motor, checked the bushing, aside from the seals, it seemed to be all there.

Fired it up ( manual ignition) and it worked great. Kept it running (outdoor) for hours , all good.

As I was going through the unit, I wanted to check the safety vacuum switch (single barb, neg pole). I disconnectected the hose (Vac switch to exhaust housing) and fired it up.. It kept running, the auger motor never stopped as it would have (from my understanding).

So I disconnected the leads to vacuum with and tested the switch. Sitting on its own not connected to stove and with electric leads removed, the switch is CLOSED. (?)

Should it be?????

I can't wrapped my head around this one.. Imagine, the hose breaking and later the exhaust motor failing, the auger would keep feeding???? Can't be right..

Anyway, if someone could tell me if these pressure switches are supposed to be closed in a non operating stove.

Thank you.

Here are some pics.

 

I have the exact same stove.

The switch is a "Pressure switch" and is a "Normally closed switch" N/C

This switch is there to protect from a plugged vent.

The exhaust fan is pushing air out and if the vent became plugged the pressure would open the switch and shut off the fuel feed...and then the fire would die and go out....the low temp snap switch (on the exhaust) opens and stove stops.

Sounds like things are just fine.

My A2 has the same switch. The extra wires are part of my re-wire/new controller set up.
I actually wired in a vent overtemp snap switch into the circuit with the pressure switch.

If the stove were to have an issue where the stack temp got to 250 F the manual reset snap switch will open and shut things off.

You have yourself a great stove.

Once a season remove the exhaust fan and use a bottle brush up into the air passages in the rear from the exhaust housing to get the ash loose and out.

Always remove the inner ash baffles..

As you likely discovered these baffles are like a Chinese puzzle to get in and out... but these need to come out about every other cleaning and the bottle brush inserted in and around the back passages

Get yourself some of the RED solid silicone exhaust gaskets to go on the exhaust motor flange

The lytherm (White stuff) are a one time use only.

The silicone ones are good for many uses....

 

Snowy rivers!!!!

I can't tell you how much I appreciate your reply. I have been strugling with understanding this switch for a week now..
So the switch actually measures over pressure in case the vent gets plugged and in the event of an exhaust motor failing, the OverTemp switch will shut down the auger. Then the low temp would eventually de-power the whole thing. right?

Thanks for the tip about the red gaskets, I am now on a quest to find those.

Yeah I found ashes in places in there that I couldn't reach very well. Baffles removed etc but still finding areas with ashes.

I am glad that everything is looking good to you. When you have a sec, could you tell me what type of vacuum hose do you use. I imagine that with the heat, it is something that needs to be replaced after the burning season is over.

Also I have to ask, what is this? (red circle in the pic), overheat sensor on the vent pipe with Temp control gauge on the pipe?

Thanks again for your reply.

Fred

 

(I actually wired in a vent overtemp snap switch into the circuit with the pressure switch.)
This is what Snowy Rivers installed on her vent for extra protection on overfiring.
Welcome to FHC

 

Thanks. that’s a great idea.. what is the temp rating of the ceramic switch?

 

Only Snowy Rivers knows. Probably the same rating or a tad higher?

 

Thanks

 

That is why all the newer stoves have a normally open negative pressure (Before the exhaust blower) vacuum switch. If the hose falls off or the exhaust blower dies, the pellets will also stop feeding.

 

I've checked Snowy Rivers post on the snap disc rating ; 250*F

 

YESSSSSS 250 F

Sadly the older Whitfields did not have a protection to deal with a fan failure.

What Don said ...that's the ticket





.

 

thank you Don,
I am going to do some research but would you know if there is a way to retrofit older stove with this neg pressure switch safety feature.

Thank you.

 

Thank you Snowy Rivers!!

Just wondering, have you tested your setup with the 250F manual reset snap switch? How long would it take at Min heat setting to trigger the switch? I am trying to get some idea of worse case scenario, Low feed and no exhaust blower.
I will definitively install the "Snowyriver Auxillary Fan Exhaust Tempswitch Youmusthave" device... Makes a lot of sense to me.. I like it.
Thanks again you ve been of great help.

 

I have a magnetic thermometer stuck on the vent.

150 F is about normal running on #3 setting.
I have had it at 170 F a time or two.....150/160 F is just about all we see.

The safety is in case of an over firing that could, maybe, possibly happen or ???? due to a control failure..

At 250 F the snap will open and shut it off.

We run the stove 24/7 for long periods away from home....I want it safe.

 

Glad you like the ideas.

Always happy to help.

 

To add the switch Don spoke of

Drill and tap a hole in the exhaust passage on the firebox side of the exhaust housing.

Tap for 1/4" pipe thread..

Put a nipple into the tapped hole with the nipple sticking up and the threaded portion aiming into the housing... this will stop ash from entering the nipple and clogging it.


Mount the switch and connect to the nipple in the exhaust housing with red silicone hose.

Wire into the same circuit as the other switch.

All in series....
As long as there is no issues the auger will operate.

Fan quits...auger stops
Exhaust gets plugged...auger stops
Overtemp...auger stops

Simple thing

 

Thank you. Going to work on this and will report back.

 

If you are not sure of something....check in before you hack on it..

 

Thanks SnowyR, I will. Finally got my new parts for the whitfield, I tested the new pressure switch and this one is open, it closes when you apply a slight vacuum pressure .
I am going to install it and test it with the new exhaust blower motor as well.
Take care and good weekend.

 

Way cool.

Let us know how it works....

 

I replaced all the seals of exhaust blower and fan blower as well. Replaced vacuum switch, installed new red hose. Installed neg pressure switch as described by SnowyR. Checked the door seal (was good). Tested the Low and High temp switches. Cleaned everything up and started the stove. Ran a few tests, clogging exhaust pipe> Auger stopped... Unplugged exhaust blower> Auger stopped. Happy here!!!

Got some more snow this am and feels nice to be by the stove..

Thank you again for all your help.

Stay safe

F