Water heater plumbing

Jeffrs

Hello all, sorry if this isn’t really the proper place to ask. I tried searching and also just tried googling to get an answer. Thought I’d ask here being a member with heating help before trying to join a plumbing forum. 

Leaky elbow on the hot water copper line running out of the hot water heater has rusted the fitting at the tank. Cold water inlet, while it is not wet like the hot side, is also developing some rust issues at the copper to water heater nipple connection. Looking to replace the dip tube and both nipples at the water heater, and will probably re-plumb both side with flex lines while apart. It’s a rheem water heater, looks like it’s a dip tube with the nipple built in on top. Waiting for rheem to confirm what the proper replacement dip tube is for my particular water heater. 

My question is, do I use heat trap nipples? Or just dielectric nipples? Is the nipple attached to the dip tube already dielectric? I’m planning to go back together with stainless braid flex lines, not sure that I really need dielectric nipples then? What about the heat trap nipple, do I couple that to the dip tube if the dip tube is the type with a built in nipple?
Thanks all for any help,
Jeff

Ironman

You can get the plastic coated nipples at a plumbing supply. They’re considered dielectric due to the coating isolating the water from the nipples.

You need to remove the anode rod and check its condition. If it’s eaten up, then it’s probably time for a new heater.

If it’s in good condition and the heater’s not very old, I’d use two brass nipples instead of the coated ones.

I’ve never seen a plastic dip tube wear out.

hot_rod

In some cases the dip tube is part of the cold nipple, same with the anode rod being attached to the hot nipple. Most heaters now have trapper nipples, either the flapper or ball type

If your piping is above the heater the nipples prevent thermal migration

year ago there were a batch of dip tubes that turned to powder with certain water conditions. It was a mess, plugged up washers and dishwasher solonoids

EBEBRATT-Ed

A ground wire between hot and cold somewhere near the heater may help

Ironman

hot_rod said:

year ago there were a batch of dip tubes that turned to powder with certain water conditions. It was a mess, plugged up washers and dishwasher solonoids

@hot_rod
Do you know which manufacturer(s) used the faulty dip tubes?

Jeffrs

Thank you all for the quick responses. The heater is 7 years old now, will be 8 years this summer coming. Purchased the house last year and the leak went from a drip every so often to a drip about once a minute. It’s enough to have rusted the hot water side fitting pretty good. I was planning to pull the anode and check it out as well. The cold side does have a ground wire attached to it, nothing on the hot side though. Should I add a jumper between the hot and cold pipes? 
Im planning to replace the water heater this summer, but the hot side nipple and leaky pipe above it, is bad enough that I don’t want to let it go for the time being, as I worry it’ll blow while I’m not home to tend to it. For the cost of the new nipples and a dip tube, it’s cheap enough to do, and then I’ll have the plumbing to it tidied up for the installation of a new heater later on come summer. 

So a couple more questions, the anode is on the back, under a plug. Are they typically pipe thread? Or is there a gasket that seals them?

I’m going to use the heat trap nipples, looks like actually the original dip tube sits below the nipple and not the type that comes with the nipple attached to it. Are the dip tubes, whether they come with the nipple attached or not interchangeable as long as length and diameter is correct? 

Thank you all again. 

Larry Weingarten

Hi, Here's a drawing of how I like to see a heater put in. I'm not a fan of heat trap nipples, but by using long insulated flex lines, you get the same or better effect with better flow. About dielectrics, using flexes with dielectrics built in along with lined nipples gives the best protection and longevity. The hex plug anodes are 3/4" pipe thread on residential heaters and need a 1-1/16' socket to remove. No gasket. Use magnesium only if you might drink or cook with the hot water. Yes, do add a jumper, (#6 solid copper) between the lines above your flex connectors.

If the old anode has metal on it, the tank is probably fine internally, but tanks rust easily from the outside, so that leak could have weakened things.

Yours, Larry

hot_rod

Ironman said:

hot_rod said:

year ago there were a batch of dip tubes that turned to powder with certain water conditions. It was a mess, plugged up washers and dishwasher solonoids

@hot_rod
Do you know which manufacturer(s) used the faulty dip tubes?

Guess it was longer ago than I thought🥴

Jeffrs

Larry Weingarten said:

Hi, Here's a drawing of how I like to see a heater put in. I'm not a fan of heat trap nipples, but by using long insulated flex lines, you get the same or better effect with better flow. About dielectrics, using flexes with dielectrics built in along with lined nipples gives the best protection and longevity. The hex plug anodes are 3/4" pipe thread on residential heaters and need a 1-1/16' socket to remove. No gasket. Use magnesium only if you might drink or cook with the hot water. Yes, do add a jumper, (#6 solid copper) between the lines above your flex connectors. If the old anode has metal on it, the tank is probably fine internally, but tanks rust easily from the outside, so that leak could have weakened things. Yours, Larry

Thanks Larry, that drawing is helpful. Thank you for the advice on the heat trap nipples, anode and jumper. 

Jeffrs

MikeAmann said:

You might open a giant can of worms by messing with this. You might not be able to budge anything because of the corrosion. I have never used it, but you might want to use FLEX TAPE after using a wire brush to remove as much corrosion as you are able to. Then seal that drip with the tape. This should get you to the summer when you planned to replace anyways.

Thanks. The thought has crossed my mind that trying to pull the nipple might become a bigger issue. The leak is coming from a copper elbow about 6-8 inches above the hot outlet nipple. I have to look again, but if I can find a clean spot on the copper between that elbow and the nipple, I could just cut the copper away, leave the nipple with the copper coupler still on and sweat a new section in. 

mattmia2

Make sure you get a 3 point bite on the nipple with the pipe wrench so the back of the jaw is touching as it clamps down so you don't crush it and it will be fine.

I would use brass nipples, no heat traps, no dielectric beyond the nipples and plumb it in with copper pipe all the way, no flex connectors. I would use copper unions but if you are feeling lucky on the threaded connections those aren't strictly necessary. Use dope and tape on the brass connections.