Older Earth Stove TP440 not cycling on loer speeds

[Used tp 440]

Hello, Thanks for letting me join. I bought a used Natural Fire Earth Pellet Stove. It appears to be a mid to late 90`s model. I installed it recently and it only works (feeds) on high. It won`t work (feed) on the lower cycling settings. Any ideas?

 

[Ssyko]

Your control panel is an analog with a potentiometer for the heat/auger control. It very well may be its worn out. You could try unplug the stove and pull the dial knob off and spray some electrical contact cleaner down the side of the shaft then move it back and forth a few times and clean out some crud and it may work again.

 

[Used tp 440]

Actually the only knob that turns it the room air blower fan and that works fine. The panel also has a red push button for start. There are 2 slide switches for the fuel rate control and draft fan.

 

[Ssyko]

Ok you can still use contact cleaner on slides, it’s actually easy on them than a pots

 

[Used tp 440]

Ok, I will try that. Does anyone have a supply of those old control boards?

 

[Ssyko]

Pretty old stove, most have digital boards now. If you google your stove thers replacements out there.

 

[Stovensen]

Does anyone have a supply of those old control boards?

https://woodheatstoves.com/products/earth-stove-pellet-stove-control-board_28m61

$432,- is a bit pricy. Would repairing the old board be possible? Link to a repair service: http://pelletstovecontrollerrepair.com/

I just found the user manual for the TP340 (The TP340 and TP440 should be technically identical)
The manual is quite detailed on the troubleshooting, wiring diagram etc. I've attached the manual below in case you don't have it already.

These old Earth Stoves are very interesting machines, based on the Traegers original patent from 1985. Wow, almost as old as the world's first pellet stove for residential use, the Whitfield Legend from 1984.
I really hope you'll succeed in repairing this wonderful heating machine.
Here's some interesting info on the Natural Fire Earth Stoves, model identification etc:
https://woodheatstoves.com/blogs/wo...pellet-stoves-specs-photos-for-identification

Good luck and take care. Keep us posted

TP340 user manual attached below

 

[Used tp 440]

My control board is different then the one in the link. I will see if I can post a pic. There is a guy on ebay that says he repairs them but he want like $275 to do it. If it is just a matter of replacing a switch or something. I probably could handle that myself. I`m just not sure how to go about testing it.

 

[Used tp 440]

Ok, I tried the stove again but followed the steps exactly in the manual. It worked this time. I hope that was all it was. On the medium setting it cycles feeds every couple minutes. With the stove on medium what should the draft fan be set on? I have it on high. Should it be on low? The book says low the fan runs at 50% of capacity when not feeding and on high it runs at 75% of capacity when not feeding. One more question, Can I mix corn with the wood pellets. Would it put out a hotter flame?

 

[Stovensen]

Ok, I tried the stove again but followed the steps exactly in the manual. It worked this time. I hope that was all it was. On the medium setting it cycles feeds every couple minutes. With the stove on medium what should the draft fan be set on? I have it on high. Should it be on low?

The setting of the draft fan depends on several things: Pellet quality, venting configuration etc. You'll have to experiment with different settings, until you find "the sweet spot", where the flames start to dance without any pellets being blown out of the pot. But no way should the flames be lazy with a black tip ( lack of combustion air).
Remember that your stove is quite rare in that it uses positive-pressure-combustion air in the burn pot: The draft/combustion blower blows directly on the pot from underneath.
On the majority of pellet stoves it is the opposite: The combustion blower is making a vacuum over the burn pot due to its location in the exhaust close to the flue connection.
Note: On a pellet stove with positive pressure combustion it is very important to keep the gaskets ( especially the door gasket ) in perfect condition to avoid flue gasses from entering the room. If there's even the slightest smell of smoke from the stove, please check and replace the involved gaskets immediately!

One more question, Can I mix corn with the wood pellets. Would it put out a hotter flame?

I have absolutely no experience with burning corn, so more experienced members will have to help you on this. According to the manual there was a special corn burn pot. But can the standard pot burn a mix of pellets and corn? Good question. Once you have the stove dialed in and have become more familiar with it, you could give it a short try with some pounds of the mixture. Let us know how this turns out.

 

[Used tp 440]

The first thing I did was replace the door gasket and gasket under the top lid. That was something I struggled with on size. The old gasket that was on the door was 1/2. It appeared to have been replaced before. The manual says to use 3/4 inch. The lid gasket appeared to be original and it was 3/4 inch and I replaced it with the same. When i contacted a stove store about the door gasket they said Lennox (IIRC) recommended 1/2 and 5/8 if not sealing well but the info on these stoves is limited since not much info was saved when Earth Stove was bought out. I tried 1/2 inch and it didn`t seal well. I stepped up to 5/8 and it appears to be sealing well. The 5/8 really seems like the correct size. I can`t see a 3/4 seal on that door. The groove for the seal and having to go around the handle it just seems too big when I tried one to test fit. Thanks for the help on this.

 

[Used tp 440]

Ok, Back again. The stove ran on medium fine all night. It ran out of pellets and I let it cool down and cleaned. I tried to get it to work again but I think I found the issue somewhat. The manual says once the stove reaches temperature the fan will come on and once the fan comes on I can then turn it down to medium. Well the fan won`t come on even after the stove gets very hot.. I can manually turn the fan on thru rheostat but I can`t lower the feed speed because of that. My question, what detects the temperature of the stove for that operation? Is it the safety disc or the fan speed disc? Where are these discs located? I know where the blower and burner resets are but i don`t see those discs. Do I need to remove the lid? Can the disc be cleaned from the inside if the stove or are they not accessible. Can these discs be purchased still? Sorry for all the questions.

 

[Stovensen]

Is it the safety disc or the fan speed disc? Where are these discs located? I know where the blower and burner resets are but i don`t see those discs

This video from WoodHeatStoves shows the location of the 3 prong fan speed disk and the manual reset disk on a HP40 behind the control panel. Most likely these disks are also located there on your TP440? The video has many other useful informations, so I'll recommend you take your time to watch the entire video:


If the 3 prong fan speed disk turns out to be faulty, a replacement can be bought here for $21.95 :
https://www.ebay.com/itm/Earth-Stov...0-2-611015-3-prong-Instructions-/112175805498

The seller of the fan speed disk has this useful info on the function of the disk:

"The fan speed limit disc is usually used in Earth-Stove pellet stoves. This snap disc has three wire connections for sensing temperature rise and turning the convection blowers to full power when it rises over 140 degrees. It overrides the rheostat control.

It is a good habit to turn the rheostat dial to low or medium setting once the stove warms up. This provides a more efficient stove operation and less on-off cycling of the blowers."

 

[Used tp 440]

Thanks for the research. I did find that disk after finding the part number in my manual after making this post. I will give it a shot. Thanks again.