3nickles said:
I had a Country PI-40 Pellet Insert installed last season and am very happy with the unit overall, but I have one lasting complaint. This stove was advertised to have an air wash system which delivers an average of 30 days clean burn without cleaning the glass. The front panel glass becomes dirty after only about 3 days of burning (avg 6 hours a night, not all day burning). Needless to say from a maintenance standpoint I'm a little upset as this is one of the main reasons I purchased the stove. I've contacted the dealer but since they don't sell many of these they're not sure what the problem might be.
I have contacted Country directly and the tech's only suggestion was to increase the blower speed or high-altitude setting: I think they're one in the same but not sure. I'm waiting for my yearly cleaning so I can tell the installer to do this and I'm crossing my fingers it will work.
Has anyone had an experience with a Country Pellet insert or similar stove? Please share if so!
3nickles:
I have a similar problem with my PI-40 stove. The sooting problem that you're describing is caused by insufficient quantity of combustion air. After a careful root cause analysis (see attachment), I found that the combustion air problem can be traced to the following causes: Draft (i.e., resistance in the exhaust), combustion blower speed (i.e., air flow volume to support combustion), Clinkers (i.e., obstruction of burn pot air passages).
To solve the sooting problem, I asked the stove dealer technician to do the following:
Draft: Check the damper/draft to control to ensure it was fully opened. The technician discovered that although the manual indicates that the stove is shipped with the damper in the full open position, the reality is that it's shipped in the "standard setting" with 3/4 inches restriction. I instructed the tech to open it fully to ensure unrestricted passage of intake air for combustion.
Blower Speed: The PI-40 blower speed can be adjusted by changing the high altitude setting in the control board. Using a diagnostic tool, this parameter can be changed from O (sea level) to 50 (unknown highest altitude). The higher the number, the higher the speed of the combustion blower to compensate for the lower density of air at high altitudes. Initially, we set the compensation to a value of 25 but after running the stove for a while at various heat output settings, I think that I need to set the compensation to a higher number because at the HIGH heat output setting, I'm still getting some sooting, which indicates that the stove is not getting sufficient air to properly combust the pellets at the HIGH setting. I ordered the diagnostic tool and plan to "tweak" the high altitude compensation to find the setting that provides the best air-to-fuel ratio (aka stochiometric ratio) for the high setting. One word of caution is that if the combustion air flow is set too high, the pellets will burn quickly and will not provide their maximum energy content.
Clinkers: These silica deposits are formed due to impurities in the pellet composition, improper combustion, and by repeated heating and cooling cycles, which is typical of stoves that are controlled by a thermostat. The clinkers obstruct the air passages on the burn pot and reduce the combustion air flow to the combustion chamber, which in turn produces sooting and more clinkers. This is a self-perpetuating vicious circle that is more annoying when a thermostatically controlled stove goes into a normal shut down cycle but when the thermostat calls for heat again, the stove cannot reignite because the clinkers prevent the pellets from reaching ignition temperature. Vicious and obnoxious are words that come to mind! Although I'm burning Eureka Premiun Grade (low ash content) pellets, I've found that Eureka has a tendency to produce clinkers (I also have a Whitfield self-standing and clinkers are formed to a lesser extent). I will switch to Cubex or Quality, which I found to be less prone to clinker formation, if any. In addition, for the time being, I'm not controlling the stove with the thermostat to prevent heating and cooling cycles that foster creation of clinkers. Perhaps I will return to thermostatic control, if I can find the right pellets and the right combination of combustion air adjustments (aka: a stove's sweet spot) to preclude clinkers.
If all of the above fail and your stove still suffers from a sooting problem, your only alternative (short of returning the stove, as not all stoves are not created equal even same brand and model due to manufacturing tolerances - subject of possible future discussion) is to hook up the stove to take outside air for combustion. The reason is that the outside air is denser than the air inside the house because it's colder. The denser air packs more oxygen molecules per volume, which supports a better combustion.
I hope that my recommendations will help you attain Nirvana -- a soot free running pellet stove!
Now, since you have a PI-40, have you ran into any problems concerning the fire going out but there're pellets still in the hopper. The pellets are hung up on the hopper and never slide to the bottom to be picked up by the auger. Eventually, the auger starves and the pellets are not conveyed to the burn pot, and the fire dies. I think that there are a good 10 - 15 lbs of pellets hung up on the hopper, which makes a 50 lbs hopper capacity stove effectively burn only 35 lbs of pellets without refill or human intervention (i.e., manually pushing the pellets to the bottom of the hopper). I have some ideas on how to solve this problem but wanted to find out if this is a common problem (In line with: Not all same brand and model stoves are created equal!)
Good luck 3nikles!
Very Respectfully,
deuce
PS: You may want to check the build up of flyash on your exhaust venting system. The PI-40 has a clean-out box to which the flue pipe is connected. You'll have to remove the right surround side panel (houses the control board) to access the clean-out box. The box has a latch that opens a door that faces the floor. When the ash is cold, you can a use a vacuum cleaner (preferably an ash vacuum cleaner) to clean out the flyash that has accumulated after prolonged use.