Wow, something I'd never really thought about but very interesting!

Good smart fix! Love it when that happens, a bigger job becomes and easy straightforward fix. I would never accept that price. Every person must decline a severely marked up product. Retrofitting a water heater would be about 1000 dollars all in, which yes is reasonable and its really the cost of materials and labor i believe. You do great work Reuben, that is probably because of having a really great family. I work on things like that all the time, and its a challenge, but if done smart, can always be solved and improved. It just takes some generational know how. I think youre the right guy to ask,,, do you know of any air conditioner/ heat pump units with a very "Undersized Compressor"? For efficiency? I think having a 5 ton condenser and 5 ton evaporator, but with only a tiny 1.5 or 2 ton compressor Shouuld increase, double, efficiency, coefficient of performance, from around 3.5 up to 7. But, less capacity than 5 ton obviously. Dont know if the old school ac tech guys make thier own home systems like this,, i have read some studies that say its the best way. You know. Others attempt with vfd which is interesting, using slower compressor speeds, for less tonnage, but less wattage too, taking advantage of heat exchange to increase cop to 7 or 8 from what is studied, I might try the vfd thing, since I use solar and i dont want to pay for those soft starters, just straight up drive it with a vfd, I prefer using the central ac if the surge current wasnt so high and efficiency wasnt so low. I know you get alot of questions like this, so fell free not to reply, cause its a busy subject, but you know maybe you have some prior knowledge that might help make up my mind. Cool stuff, also, keep clean working on these units, theyre dirty sometimes. All sorts of junk cauught up in dust. Like wierd molds and weird bacteria. Disinfecting wipes would be smart, and theyre always great to have.

Smart! :)