Unknown knob

[mlambert40]

Can anyone tell me what this knob adjusts? It's on a 2003 Lopi Yankee.
Thanks in advance!

 

[DneprDave]

It looks like a fine adjustment for your fan speed.

 

[Harmanizer]

Harmans have something similar that adjust the combustion motor.It's called a low draft adjustment screw.

 

[johneh]

It's a secret check your manual
under draft adjustment . Sheee
don't tell anyone

 

[mlambert40]

Here is my manual. I am not seeing anything about it or how to adjust it correctly.

(broken link removed to http://www.lopistoves.com/TravisDocs/93508108.pdf)

 

[dozerdean]

It's a secret check your manual
under draft adjustment . Sheee
don't tell anyone

It's on a need to know basis & he doesn't need to know!

 

[bags]

Don't fix it if it isn't broken. Should be what was mentioned above. An adjustment for the draft. Stoves have this because different exhaust vent lengths may require more or less draft for optimal operation.

I am not familiar with the Lopi pellet stoves but that'd be my guess. I do have an old Lopi insert if that scores me points. Good products.

 

[mlambert40]

What does turning it up vs down do?

 

[Ssyko]

It changes the amount of vacuum in the fire chamber for locations that are higher or lower in sea leval elevation. Like bags said if it aint broke don’t fix it,

 

[mlambert40]

How can I tell it it would even need adjusting though? I seem to get a lot of smoke residue on my glass, would this affect it?

 

[Ssyko]

You have to use a magnehelic guage to adjust along with the tech manual. Soot on the window is normal unless it blacks out the glass in a short period of time.

 

[stovelark]

I'm thinking that it is for adjusting draft but what it is doing is changing voltage slightly for the combustion blower, thus changing motor speed and draft produced. Most control boards will have a little rubber cap covering that up, so its normally not messed with...

 

[mlambert40]

It smokes up a 1/3 of the glass every couple days. Is that about normal?

 

[stovelark]

Weird its not covered at all in the manual, that I could see....

 

[stovelark]

I did note that it has two "air restrictors" that seem to be adjusted for proper draft within the stove. I now agree that the original adjustment is for fine adjustments of the convection fan control as Dnepr Dave noted above... The air restrictors are what we normally see as draft adjustments to change for different pellets being burned. Your glass getting like it does every couple of days sounds pretty normal, if the stove is burning your pellets up normally, and not building up crud in the burnpot, sounds like its doing ok to me.

 

[bags]

Haze and light ash build up are perfectly normal on the glass running about any pellet stove even with low ash hot burning pellets. It's just the nature of the beast. I haven't seen a glass "air wash" system that theoretically works like they are advertised on any stove. Pellet or wood burning.

My stoves usually get the upper 1/3rd of the glass hazed up fairly quickly. Research glass cleaning and such on this subject because there are many discussions about it all over. If it bugs you develop a cleaning regime every few days. If mine gets crusty I'll get a DRY soft towel and wipe it down when I crack the door real fast to scrape the pot. Burning wood and pellets has its compromises.

 

[Deezl Smoke]

Here is my manual. I am not seeing anything about it or how to adjust it correctly.

(broken link removed to http://www.lopistoves.com/TravisDocs/93508108.pdf)

I'm not at all familiar with your stove, nor have I yet read your manual, but 9 times of 10, an adjustment that needs a tool and has no end user knob or label, is a technician or factory trim adjustment of some kind.
On older carburetor based engines, a screw like that would be used to adjust the fuel/air mixture at idle. I would then imagine as several have mentioned above, that since a stove burns a fuel and requires air, that screw may do just that, adjust or trim something in the fuel or air delivery.
?

 

[mlambert40]

Thank you very much to everyone for the input and info. I truly appreciate it

 

[Stovensen]

Mlampert40, the overall design of your Lopi Yankee appears to be somewhat inspired by the old Whitfields of the 80's and 90's.
On Whitfield stoves with the touch pad control we have three trimpots similar to the one on yours.

The function of these trimpots are described in the manual for my Quest Plus:

Locations of the trimpots:



The convection blower trimpot on the backside is particularly interesting. Note this sentence concerning the convection fan trim:
"This can be used to eliminate fan noise by trimming fan speed slightly above or below a noise band."
Electronically the control of the motors is done by triacs switching the ac sinewave very precisely at certain angles of both the positive and negative halfwaves.
The #3 setting is the one I use the most on my stove and in the first months with my stove, I was annoyed by a horrible whining noise from the room blower at this setting. I even hooked up a handheld oscilloscope to the blower voltage to check if everything was perfectly symmetrical. On this video of the set up you can hear the awful whining sound climaxing at the #3 setting.
All it took to eliminate this was tweeking the trimpot slightly
Also note the rather violent damped oscillations that occur immediately after the triacs cut the halfwaves to the inductive load. To ensure safe triac operation here, an RC snubber circuit has to be present on the circuit board.

RC snubber circuit, technical background:



The whining noise is most noticeable at the 1:08 time mark:

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[mlambert40]

Mlampert40, the overall design of your Lopi Yankee appears to be somewhat inspired by the old Whitfields of the 80's and 90's.
On Whitfield stoves with the touch pad control we have three trimpots similar to the one on yours.

The function of these trimpots are described in the manual for my Quest Plus:
View attachment 222352

Locations of the trimpots:

View attachment 222353View attachment 222354

The convection blower trimpot on the backside is particularly interesting. Note this sentence concerning the convection fan trim:
"This can be used to eliminate fan noise by trimming fan speed slightly above or below a noise band."
Electronically the control of the motors is done by triacs switching the ac sinewave very precisely at certain angles of both the positive and negative halfwaves.
The #3 setting is the one I use the most on my stove and in the first months with my stove, I was annoyed by a horrible whining noise from the room blower at this setting. I even hooked up a handheld oscilloscope to the blower voltage to check if everything was perfectly symmetrical. On this video of the set up you can hear the awful whining sound climaxing at the #3 setting.
All it took to eliminate this was tweeking the trimpot slightly
Also note the rather violent damped oscillations that occur immediately after the triacs cut the halfwaves to the inductive load. To ensure safe triac operation here, an RC snubber circuit has to be present on the circuit board.

RC snubber circuit, technical background:
View attachment 222355


The whining noise is most noticeable at the 1:08 time mark:

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For more detailed information, see our cookies page.

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Great information, Stovensen. I will tinker around with it to see how it affects my unit. Thanks!