I don't mind the questions a bit. If I didn't want honest dialogue, I guess I chose the wrong place to be huh?
Anyway to answer your questions...
Thermo Ash Monitor- The effenciency improvements I spoke of aren't any that we have numbers to support. However, it is simply my personal view that improvements are achieved throught not having the fire go out, as well as not wasting unburnt coal due to the grate moving too often.
Modified Sight Tube Cover- While the plain flapper allows air to pass over the coal in off-cycle, the new flapper adresses the issues caused by high volatile coal. The new cover allows an adjustable amount of secondary oxygen supply into the combustion area.
Heat Switch for Hopper- The previous boilers weren't "unsafe". Also, there was no recall, which we would have done if they were unsafe. However, we saw an area that could be improved, so we took steps to do so. Think of it like air bags... is a car with 2 side air bags not safe, or is the one with 4 simply more safe?
All these upgrades can be installed in the field.
I hope these answers help you out.