Yeah, I messed up...

I am missing the dielctric union. I'm going to remedy this, but I want to replace the nipples that go into the water heater as well, lots of crud in them, they seem to have deteriorated.

This is a Rheem water heater, can I just back them (the nipples going into the WH) out with a plumber's wrench? Or are they somehow welded in? Just don't want to do more damage...

Thanks in advance for your advice!

They should spin right out with a bit of force.

Thanks! I'm learning about heat trap nipples, I don't need that if I go with the dielectric union, right?

Why dielectric union? Just curious.

I have always attached my piping right to the water heater's nipples. Never used dielectric unions, never had a problem. Those galvanized steel couplings you used to connect the nipples to the quick connect is the reason for all that corrosion.
Also off topic that pex piping is to close to water heater flue pipe.

I just make it a rule of thumb to never use galvanized.

And on a gas heater use 18" of copper pipe from the top of the heater then adapt to whatever.

Thanks for your replies, I appreciate the wisdom.

I replaced my whole system with pex due to a slab leak (I'm in southern California). When I attached to the WH about 2 months ago, I pulled off the old copper flex connections and found the factory heat trap nipples full of black decayed stuff that seemed like charcoal, now I guess it was the plastic linings? That was when I added the galvanized couplers, after scraping out the junk in the heat trap nipples with a screwdriver...

So, voletl, would you replace the nipples coming out of the WH with brass nipples? Or just put in a copper flex connector to the existing? Not sure how corroded the existing nipples are but they look bad from the outside...

spcwaters, thanks for your input, do you know what kind of metal the heat trap nipples coming out of the WH are? It's a Rheem / GE WH. I was going to put new galvanized nipples in, thanks for the warning!

I have read about lots of problems with the heat trap nipples so I want to avoid these if possible.

Thanks again!

They sell water heater nipples in any hardware store with the plastic lining in them. Depending on the water heater sometimes the cold water inlet nipple is attached to the dip tube. You should contact rheem and see if they'll send you out replacement nipples for your water heater maybe get them free of charge if you're lucky