Need advice on repairs of copper pipes at water heater

[Blindog]

Hi to all and forgive me for diving right in. I'm not a professional plumber but over the last 40 years I've plumbed a few houses and I do all my home related repairs. My daughter recently moved into a house and there is much corrosion and some armature looking work around the water tank (electric) and I want to straighten out some of the work. The solder joints look sloppy/corroded and a few are leaking. The original "plumber"reduced the feed into the house to 1/2" and plumbed everything with 1/2". There is a saddle valve that is leaking and corroded for the humidifier that was tapped into a hot water line. Fortunately most of the branches are in this area and I have the opportunity to get rid of a lot of past sins.
My Questions:
1. I am familiar with copper sweating and have never used this new clip style fittings, Is sweating still an acceptable method?
2. I've always used 3/4" to feed the main lines and break of with 1/2", does this make sense?
3. I would like to attach to the current low height water tank but make it easy to update to a tall tank at a latter date. Are there flexible feeds that would allow for this?
4. I suspect a check valve is in the system so should I consider an expansion tank?
Thanks, Tim

 

[Gary Swart]

1. Sweat is preferred unless in a tight spot when there would be a fire problem.
2. 1/2" is too small for a main. You are on the right track.
3. There are flex copper lines in various lengths. These are actually required in some areas.
4. An expansion tank is required if you have a closed system. This would be if you have a pressure regulator. If the check valve is located in the supply line, that may likely create a closed system also, but not sure on this. A PRV and expansion tank are both needed if the water supply is 80 psi or more. 40 to 60 psi is really plenty of pressure.
6. Get rid of that saddle valve and install a 1/4 turn ball valve with adapters to reduce and connect to the 1/4" tubing.

 

[Sponsor]

 

[Terry]

3/4 works for a one bath home.
1" works for most two and three bath homes.
If you install flex connectors to the water heater, don't expect to be able to reuse them anyway. If I pull them, I throw them out and install new.

https://terrylove.com/watersize.htm

 

[Blindog]

1. Sweat is preferred unless in a tight spot when there would be a fire problem.
2. 1/2" is too small for a main. You are on the right track.
3. There are flex copper lines in various lengths. These are actually required in some areas.
4. An expansion tank is required if you have a closed system. This would be if you have a pressure regulator. If the check valve is located in the supply line, that may likely create a closed system also, but not sure on this. A PRV and expansion tank are both needed if the water supply is 80 psi or more. 40 to 60 psi is really plenty of pressure.
6. Get rid of that saddle valve and install a 1/4 turn ball valve with adapters to reduce and connect to the 1/4" tubing.

Thanks for your reply and confirmations. I'll assume I can attach the shorter tank with longer flex attachments and make sure the taller tank can be accommodated with shorter flex lines. I'm surprised at all the minerals that surround the minor leaks and I'm wondering if the corrosion caused the leaks or if it was just poor craftsmanship. I assume I should consider a dielectric fitting system? I thing the tank has some factory nipples that supposedly provide this protection but I want to provide the best insurance. I plan on replacing all the 1/2" valves that were soldered in place. Are ball valves the way to go? I want to insure good flow. And finally, considering I have my shopping list together and I'm not fond of buying from the big box stores, Are there good internet businesses I can deal with that provide good quality or am I off to the local plumbing shop? Thanks again for all the suggestions and advise. Note: None of the joints appear to have been wiped after sweating and I wonder if excess flux has created some of the corrosion issues.