They can gum up a good well in a moments notice. 

If you are doing the DIY servicing, that is probably your issue and I don't know of a way to duct tape and bubble gum the two worlds together.  

Houses, skateboards, bubble gum.    

If you run out of oil, the heater will suck up sludge from the bottom of the tank and gum up the system.

So what am I gumming my mouth about here?

even if  removing the tiles,.you still have to level the floor and remove all the old mastic or grout.

I love gum almost as much as I do science. 

If it had been an older stand of lumber quality trees the harvester would have paid for the wood and done it all at once because of the value.If they're another type of tree they may have value as landscaping trees(Oak, Holly, Birch, Sycamore, Sweet Gum) and you might be able to get a nursery out to dig them all for sale as landscaping trees.That may be something that to consider as well is find a nursery that would like to lease the property for a tree farm.

You have the guy at the mall chewing gum, the sleazy guy at the car lot, or some highly successful corporate salesperson.  

Is the pet appropriate to the unit leased, is there some small child next door, is it a house in a rural area, case by case decision.A four year old Doberman or a 12 year old Doberman that gums is special diet dog food?