I have a Lennox Winslow P140 insert. I'm hoping someone can help with this question. Last fall after running my insert for 1.5 yrs., I called the installer to have someone come to do a yearly maintenance/cleaning before last winter. They came and since I'd already done a normal removal of ashes, all they did was open the ride side access and vacuum out around what I guess is the combustion blower which I'd been doing every couple of months anyway. They charged me $90 and said that's what was included in a yearly maintenance routine. I'm limited in who I can find to do this work in this area and I know I should just learn to do the stuff myself but..... Last winter, I started to have a buildup of ash on the little ledge above window and so the window became blackened much more quickly than in the past. For sure I figure I need a real "check up" with the flu pipe, etc but I need to know what I need to specify that needs to be done so I can then get a cost estimate and make sure I'm actually getting the stove checked out. When I call for a furnace system/AC check-up, they have a list of what is done. I need to be able to make sure I know what should be done. For example among other items, the manual says the proof of fire switch should be cleaned after 100 bags of fuel is burned so I would expect this to be on a yearly maintenance list, right? So what should a yearly check up include and generally what should be the cost?