Brushed and vacuumed flue pipe and heat exchanger Replaced oil filter, nozzle, and strainer Checked all electrical connections and safeties Performed combustion and smoke tests 9%o2 2ppm. O 0 smoke While performing the maintenance we found the firomatic oil valve handle was starting to go bad. The solder ring was starting to fall to the bottom of the handle. Attempted to thread on a new handle but found the stem of the oil valve was spinning freely. After getting customer authorization we replaced the oil shut off valve. Customer stated the hot water is very hot. Tested water temps coming out of the water coil and the mixing valve. The water temp coming out the mixing valve was only 2-5* colder than coming out of the water coil indicating the mix g valve is letting too much hot water through. Recommend replacing the mixing valve and moving it further away from the water coil. Manufacturers recommend having it at least 10 inches away due to high temps. 1/2 mixing valve