Heatilator PS35 exhaust fan speed question.

[samdweezel05]

I unplug my pellet stove during the summer months. I plugged it back in last week and the exhaust fan came on like normal for 2 minutes. I decided to move the switch from low, to medium an then to high wile it was running. On low the fan is slow. When switched to medium you can hear it speed up a bit but when you go to high, it doesn't change. This is the exhaust fan, not the circulation blower. I have the t-stat set to "off" when I do this. Am I missing a speed on my exhaust fan? I have had issues with the stove burning dirty on high ever since it was installed 2 years ago. Is this my problem? Is their not enough air flow on high to get a complete burn causing black glass and lazy flame after only a couple of bags of pellets on a fresh cleaning?

 

[St_Earl]

i'm pretty sure you have to be burning to get all three speeds.

if you have fire though and don't get high when you call for it, then you will know

a dirty burn on high could mean your feed gate is too far open.
meaning you are getting too many pellets at a time.
or possibly the inlet draft/slide plate is closed down too much.
but that inlet comes set from the factory and i've never needed to touch it.

these are just guesses. air leaks can cause a dirty burn too. but i would think you'd see it on all speeds.

but yes, if your high speed isn't engaging, i'm pretty sure that would also cause a dirty burn.

 

[samdweezel05]

Just rechecked this morning during a burn and it does not increase the exhaust fan speed when switched from medium to high. Burns perfect on medium but on high it increases the pellet drop rate but does not increase the exhaust speed. I'm not sure it should increase the fan speed but I would like to know for sure.

 

[St_Earl]

both fans should definitely increase on high.
very noticeably so.

as i so often say, i'm by no means an expert.
but it could be just the (3 speed) switch.
since the motors work, it seems like it would be something other than the motor itself.

maybe someone here will have an idea what that/those other something elses could be.

 

[samdweezel05]

both fans should definitely increase on high.
very noticeably so.

as i so often say, i'm by no means an expert.
but it could be just the (3 speed) switch.
since the motors work, it seems like it would be something other than the motor itself.

maybe someone here will have an idea what that/those other something elses could be.

Yeah, I doubt it to be the motor. The switch is working on high because the pellet rate increases as does the circulation blower speed when switched from medium to high. My only real problem with this is it has done this since day one and the exhaust fan has never increased on high. I just never really thought about it until now. The warranty runs out in december on parts so I would like to make sure it should increase on high and also try and figure out what is causing it to not do it. I am going to call the dealer and see what he has to say about the PS35 that I know he has running in the showroom.

 

[St_Earl]

Yeah, I doubt it to be the motor. The switch is working on high because the pellet rate increases as does the circulation blower speed when switched from medium to high. My only real problem with this is it has done this since day one and the exhaust fan has never increased on high. I just never really thought about it until now. The warranty runs out in december on parts so I would like to make sure it should increase on high and also try and figure out what is causing it to not do it. I am going to call the dealer and see what he has to say abot the PS35 that I know he has running in the showroom.

good luck. it's great it's still under warranty.
sorry i couldn't be more helpful. : )

 

[samdweezel05]

good luck. it's great it's still under warranty.
sorry i couldn't be more helpful. : )

Sometimes it's just about saying things out loud to answer your own questions. My dads quad had 3 speeds for the exhaust fan. The PS35 should as well according to the dealer. Looking at the wiring schematic in the owners manual I see the exhaust motor speed is dictated by the control board inside the unit and nothing else. I need to get a tester on the motor wire and see what voltage I get on low, medium and high. I would suspect the voltage isn't changing coming from the board when I go from medium to high and this would indicate a faulty board unless I an missing something else that would have some kind of control over the fan speed. I do not believe I am. The dealer will get me a board if that is the problem. Maybe there is just a relay on the board that needs to be replaced. I won't know until I get the case off it when I get a chance.

 

[MikeNH]

Just rechecked this morning during a burn and it does not increase the exhaust fan speed when switched from medium to high. Burns perfect on medium but on high it increases the pellet drop rate but does not increase the exhaust speed. I'm not sure it should increase the fan speed but I would like to know for sure.

I have a PS-35 manufactured July 2010. Just ran a test. The exhaust motor speed increases from low to med, but does not sound like it increases at all from med to high. The distribution blower DOES increase from med to high, as does the feed rate. Hope this helps.

 

[St_Earl]

I have a PS-35 manufactured July 2010. Just ran a test. The exhaust motor speed increases from low to med, but does not sound like it increases at all from med to high. The distribution blower DOES increase from med to high, as does the feed rate. Hope this helps.

interesting. i guess i just assumed both motors had three speeds once the start cycle completed.
now that you mention it though, i seem to remember reading that the start up cycle uses the high setting regardless of switch position.
and indeed there is no difference in speed from the middle to top position before the room blower kicks in.


i've never had a problem with a dirty burn on any setting though.

 

[samdweezel05]

I have a PS-35 manufactured July 2010. Just ran a test. The exhaust motor speed increases from low to med, but does not sound like it increases at all from med to high. The distribution blower DOES increase from med to high, as does the feed rate. Hope this helps.

Well that's good and bad to hear. It sounds to me like I will keep fight it when on high unless I can find why it burns dirty on high. Feed rate is adjusted just high enough to make it light reliably and the flame is just a bit low for my liking on medium. It is running the left over Cubex/Northern pellets I had from last year and is doing ok on medium. Maybe I just have one of those picky stoves and haven't found the correct pellet yet. The list of possible air leaks were gone through last year in great detail and nothing abnormal was found. What do you run for pellets in your ps35 if you don't mind me asking?

 

[MikeNH]

What do you run for pellets in your ps35 if you don't mind me asking?

So far all I've used in the PS35 are NEWP. On high, my flame is about 6 inches above the burnpot its highest point. I'll have to check to see where I have the feed lever set. I think it might be halfway. This could be one factor though...this stove's exhaust is piped into an 8" double wall metal chimney flue that I used for my wood stove previously, and it's a 30 foot high stack, so the thing is pulling a good draft once its warmed up.

Have you had to readjust the draft slide located under the ash pan at all?

 

[St_Earl]

I am going to call the dealer and see what he has to say about the PS35 that I know he has running in the showroom.

i'm curious what your dealer had to say.

 

[St_Earl]

ok. i was just listening as i was starting up the stove. i wanted to set it to low after start up.
thought it was on medium but it was actually on high.
this was before the distribution blower had come on, but after proof of fire.
there are indeed three distinct speeds for the combustion blower.
i switched it from high to medium and noticed a slight change in pitch. i did it a few times to be sure.
the difference between medium and high is not as great as the difference between medium and low, but there is a speed for each setting for both blowers.

it never made sense to me that there wouldn't be a higher combustion speed for the high setting. there has to be to keep the pellets from building up with the higher feed rate.

as i mentioned before, i too heard only two speeds when switching before proof of fire. but that may just be how it works.
it's kind of funny i've had the stove going on three seasons before i confirmed my assumption that the third speed works once the stove is fired up.
but when the distribution fan has kicked in, it's impossible to hear the difference in the combustion blower speed.
try listening between proof of fire and when the room blower kicks in.

maybe start it on high like i just did too. not sure if that would make any difference.
the more esoteric ways of wiring and relays and switches etc... are beyond my scope.

 

[SwineFlue]

My dads quad had 3 speeds for the exhaust fan. The PS35 should as well according to the dealer. Looking at the wiring schematic in the owners manual I see the exhaust motor speed is dictated by the control board inside the unit and nothing else. I need to get a tester on the motor wire and see what voltage I get on low, medium and high

I bought a Kill-A-Watt meter at Lowe's ($30) a few years ago. Plug your stove into it, set it to read Watts, and you can see how much power the stove is using. After the ignitor shuts off and before the convection blower starts, turn down the thermostat to stop the auger. At this point the meter is showing you the power used by just the control box and exhaust blower. Select the Hi/Med/Low settings and see if the meter changes. My Quad's blower doesn't change much, it varies by less than +/- 5 Watts between settings. It is hard to hear the difference.