zingy, Spark plugs don't just "fall out". Over time, and with previous plug changes, the plug's been (most likely) cross-threaded and the threads are now gone. You can repair the head by REPLACING IT, or using a product called HELI-COIL. HeliCoil is available from most auto parts stores. You ream out the old threads and add "new" threads using this product. Either way....will prevent the plug from coming out again. If the plug WILL TIGHTEN UP....it should NOT come out. If it does...threads are damaged. T-Man

I can't let that statement stand without some comment. Schreader leak problem -------------------------------------------------------------------------------- From another site I won't name: "Purchase yourself a core removal tool which will allow you to replace the schreader core without pumping down the system. This will work providing the valve has adequate clearence around it to accommodate the core removal tool. Some advice on the tool - Don,t over tightened the knurled nuts on the tool. Use only sufficient pressure so the connection doesn't leak, but don't crank down on them, the core won,t pass through the gasket. I use the J/B brand, but I"m sure there are other brands that will work equally as well. Be sure to use a touch of compressor or vacuum pump oil on the removal tool slide and sealing gaskets, helps it to last longer and seal up easier, good luck." This was in response to someone posting a question of removing the core without a pumpdown. If you can get your hose on a unit's schraeder valve you probably can get your handy dandy core remover tool on the fitting and extract the old core without releasing any refrigerant. Simply insert a new core in and use the tool as provided in the instructions and the new core screws in nicely. It has worked for me on more than one occassion. I, however, don't have thousands of units experience but I can say that I have found a few older units where the scraders are so inaccessible that even a hose low loss fitting can't be hooked up. For that you need another fitting made for those difficult to access engineers brain farts. Sorry Bob, you made it sound like removing a core without a pump down is an impossible task. That is misleading tho I don't doubt that you have had trouble accomplishing this. Because you said that was so.

Kinda high for a replacement coil. I would expect under $2000. Get more bids. If you have a heat pump the coils are used for heating and cooling. It may be more efficient to install a thru the wall heatpump for upstairs, if the room is not used much. The difference between 2.5 and 3 ton systems is normally less than $100 cost. 3-ton is the most common sized system made.

It is almost impossible to eliminate all air leakage at your coil, especially at the copper lines. However, the contractor should be able to seal all of the seams leaving only the penetrations for the copper tubes and drain. Those areas can be controlled but almost never 100% sealed. On the tax credit.........the furnace will qualify for the tax credit if that is your only concern. Other than that, it sounds like the contractor is doing the right thing and has agreed to change the coil. Ask for a copy of the AHRI cert upon completion.