Rusty Water

[rusty bob]

I had a new hot water tank installed about 6 months ago. It is a Rheem 50 gal. natural gas water heater. It was installed through one of the big box home centers. The problem I have had since it was first installed is that the first surge of hot water that comes out is discolored, a rusty color, and lasts for only 2-3 seconds. This happens at any faucet in the house and only with the hot water. It seems to be noticable after about 8+ hours of non-use. This never happened even once in the previous nine years with my old natural gas hot water heater.

My home has PEX piping for both hot and cold water. There is probably about 18" worth of copper tubing and fittings that connect from the water heater to the PEX cold water inlet and hot water outlet. Dielectric fittings were installed between the heater nipples and the copper tubing/fittings. There is a new expansion tank on the line. I use city supplied water.

I have unscrewed the expansion tank and examined the fitting and tank for rust - nothing. I pulled out the sacrificial anode from the tank - present and in proper size. I have drained several gallons from the tank flush valve and do not notice discoloration or sediment.

Suggestions as to what is the cause of the discolored hot water?

 

[Cass]

When was your home built?

 

[Sponsor]

 

[Mike Swearingen]

A brief surge of rusty water usually means one thing...a galvanized pipe or fitting somewhere. If it were only at a tub, then it would be at the spout. If it's all hot water throughout the house, then you must have a galvanized nipple instead of a dieletric nipple on the water heater, probably on the hot water side.
Mike

 

[GrumpyPlumber]

For starters, I asked around about subbing from the "big box" companies awhile back and from what I learned they pay approximately half what I get on my own.
I'd still be using my own truck, tools, and would be responsible for pickup/delivery of the heater or fixture.
I'd almost bet money that there's either a steele fitting tied into your water heater because the installer didn't have the right part and couldn't afford to run out for it, or the internal plastic sleeve is either missing or slipped down inside the dilectric nipple.
I've had occasion to get work from a homeowner who'd been quoted extremely high prices on installtion from one of their subs, my guess is he was adding on work to attempt to make up for the initial low commission on the job he was sent to do. (3200 for a 50 gal powervented WH along with a few "necessary" add-ons...oooph!)
Take a digital pic of the top of the heater...more than one if need be to expose all piping...submit it here and we can help you determine IF this is the case.

 

[rusty bob]

my home was built circa 1998

 

[rusty bob]

Mike,

There are two silver colored fittings screwed on both the hot and cold water tank nipples. A large nut joins the copper fittings/tubing to them. How do I discern whether they are galvanized or dielectric?

 

[rusty bob]

Grumps,

My respects to the Nor-Easter, formerly of Mass myself but don't hold that against me.

Yeah, HD gave me a good deal on the tank, installation and lifetime warranty as a result of letting them install it.

I shut off the house water supply and undid the hot side fitting on top of the tank. There was some corrosion on the inside of the fitting! I need to check it again to see if there is or is not a plastic sleeve inside. The nut that joins the copper to the fitting seemed to have a rubber washer/gasket on the inside. How do I tell if this is the incorrect type of fitting? Should I just go to HD and be sure to purchase the correct dielectric fittings and swap them out myself? I just made an appointment to have the installing company come out and assess the problem.

 

[Cass]

my home was built circa 1998

If your home was built in 1998 there should be no galvanized pipe causing the problem.

I doubt the dialetric nipples would be causing it but maybe.......there is no plastic sleeve inside.......if they were causing it it would be a 1/4-1/2 second burst at most and the rust colored water would be barely visible I would think.

To eliminate that as a possibility replace the couplings with dialetric nipples or brass nipples and 3/4" female adaptors and solder the copper piping with a slip coupling.

BTW I am also from MA....what part were you from?

 

[Mike Swearingen]

The two silver colored fittings are supposed to be the dielectric nipples (galvanized with plastic sleeve inside), but the only way to see if they still have the sleeve inside them is to turn off the gas and the water and disconnect both of the water line connections to look inside them.
No plastic, replace it with a new dielectric nipple. See if that doesn't solve the problem.
Good luck!
Mike

 

[rusty bob]

Thanks to each of you for your great replys and suggestions.

My work is cut out for my later today. I'll shut the supplies off and check for a plastic sleeve inside the fittings. I'll post back as soon as I am done.

Bob

 

[GrumpyPlumber]

Cass,

I'm from western Mass....Springfield area.

Bob

You guys pronounce yer "R's"...the correct pronunciation of lobster is lobstah!


Also, this is your decision to work on your heater...as a pro it's my "duty" to advise you it can be dangerous.
That said, I'm starting to think the trouble may not be the water connection...from your description you have dielectric with brass attached.

Suddenly occurs to me to state the obvious...HD gave a lifetime warranty...why are YOU doing a thing??
It's only 6 months old, rust in the hot water only...CALL THEM!

 

[Markts30]

If the heater has dielectric nipples on it and then a dielectric union then copper, that is your problem...
The dielectric nipples isolate the galvanized half of the union and the rubber washer and plastic sleeve on the brass side isolate the other side of the galvanized nut...
the problem is that the dielectric part (non-metalic gap) is only about 3/16" thick (the rubber washer) and is easily bridged by lime and calcium deposits...
As soon as this happens you have a small piece of steel (the galv. union half) directly attached to a large copper system and it corrodes quite quickly...
You would be better off with the dielectric nipples connected to the copper pipe directly via a copper FIP adapter or (if you want the ability to break the connection for some reason) with copper ground joint unions...

 

[rusty bob]

--------------------------------------------------------------------------------

If the heater has dielectric nipples on it and then a dielectric union then copper, that is your problem...
The dielectric nipples isolate the galvanized half of the union and the rubber washer and plastic sleeve on the brass side isolate the other side of the galvanized nut...
the problem is that the dielectric part (non-metalic gap) is only about 3/16" thick (the rubber washer) and is easily bridged by lime and calcium deposits...
As soon as this happens you have a small piece of steel (the galv. union half) directly attached to a large copper system and it corrodes quite quickly...
You would be better off with the dielectric nipples connected to the copper pipe directly via a copper FIP adapter or (if you want the ability to break the connection for some reason) with copper ground joint unions...
********************************************************
I disconnected both water lines from the heater at these dielectric fittings. First, there appeared to be a plastic sleeve on the fitting attached to the water lines, although a bit stained from the corrosion that has developed. The corrosion is occurring on the fitting attached to the tank just above where the plastic sleeve rests. There is a rubber washer between the copper above but I guess it is not enough to overcome "bridging" of lime deposits, etc. What is a copper FIP adaptor? How would corrosion be avoided in this type of setup?

 

[rusty bob]

Di-E Fitting Change

Well, the plumbing contractor for HD finally showed up this week and replaced the dielectric fittings that resided over the tank nipples. The plastic sleeve was indeed inside of both nipples. A plastic hood covered the flared copper fitting (is this an FIP?) that was at the end of the water lines. New rubber washers were added between the copper fitting and the dielectric part. Time will tell if this will remedy the situation.

There were indications of corrosion on both fittings but particularly on the hot water one. There also appeared to be an excessive solder drop at the bottom edge of the flared copper fitting which he filed away. The installer said he had not seen this happen before and thought that some excessive solder flux may have made it's way past the last solder joint and contributed to the corrosion effect.