Some pellets are horrible for ash deposits. In normal cases, ash does build up in the tubes and it needs to be cleaned. Do this once a year, or when you notice cooler temperature. You will need to take the flu off and go in from the top with an ash vacuum and try to knock it all out, then come in from the burn chamber area to get everything left over.
I have heard and have seen online discussions that the stove will need to be cleaned every couple of fills including the chamber and chimney.
Can you clarify please?
We also hear about a few select folks who need their Wiseway cleaned every week or two. :o ??? This all due to the quality of the pellets bought. Your cheaper pellets will be poorly compressed so they do not providing enough time in the burn chamber before being blown away by the draft and deposited. Cheaper pellets are also full of nonburnable material and will fill up any pellet stove with dust. For example "Rural King" pellets for $4/bag are probably not a good choice whereas a local brand to you that costs $5/bag will not cause the trouble you see.