Rusty Water in Bathroom Tub Only

[Bill Skipper]

Sorry for the long detail, but:

We moved into new construction about 8 months ago and we've been remodeling our bathroom...
At first, we rarely used the tub but did notice that for the first second or two (at most), it would run rusty (hot or cold). The builder told us that it was due to lack of use and would go away in time. So here we are 8 months later and it is still occurring, even with everyday use. If we go longer that 18 hours without turning on the water (hot or cold), it runs rusty for the first second or two.

So here's the deal: We've replaced the original faucet with a Moen Method, same problem occurred. After evaluation by builder, said to replace the fixture (that would make it a third replacement since the original). So we did, still same problem. Yesterday they replaced the entire rough-in...still same problem. I've had 3 plumbers at my house scratching their heads, with no clue on what to do next. The line is plastic (pex?) and brass...No galvanized steel anywhere.

I've read in palces that it's possible that a screw got into the line somewhere, but logic tells me that somehow the water that is left in the fixture once turned off is what's rusting...now what could cause that? Everything in that area has been replaced, including the spout - several times. Everything is new. The fact that it's both lines, tells me the odds of a screw at the right place on both sides, is pretty close to impossible. But to test that anyways we removed the lines from the fixture, waited 24 hours and then ran them straight --they ran clear! So somewhere, somehow rust is getting into the mix in a place that is all plastic and brass.
Any ideas? Suggestions? on what can be causing this?

Did you ever get a solution? I have the exact same issue plastic pipes tub has rust after 24hrs. We do not use the tub much at all. typically just grand kid visits.

 

[Reach4]

Did you ever get a solution? I have the exact same issue plastic pipes tub has rust after 24hrs. We do not use the tub much at all. typically just grand kid visits.

If the rust only comes out when you first turn on the water, and it is the same whether you turn on the hot or the cold first, I suspect you have a galvanized nipple connecting your PVC to the spout. Replace that with a brass nipple.

If you can access the back side of the plumbing from behind that panel in the bathroom closet, you can see what is going on.

While replacing that nipple, you might want to replace the diverter faucet if it is not to your liking -- such as if it dribbles too much while you run the shower.

 

[Sponsor]

 

[LorraineNeal]

Hi Terry,

Hope you can help. My daughter has just moved out of a rented property because of damp and mold everywhere especially on the ceiling and around the window in the main bedroom as the seal is crumbling around the window and also the bathroom was black. He had promised to fit a fan 2 years ago and didnt, The bath all inside on the bottom has gone rusty which he says is our fault and charging us for a new bath!. The bath is years old along with the property. How can bathing a young child cause us to rust the bath. Please help. Thank YOu

 

[dcdc73]

Terry,
This appears to be a dead issue but didn't see a final resolution. I have a similar but slight different situation. I have yellow water that comes only out of the hot water of the mater bath tub for several seconds when I first run the water but not out of any other faucet in the house. The hot water from the spout also smells like sewage for the first several seconds. The entire master bathroom was fully renovated just a few months ago and the bath has not really been used (separate shower next to it). Any guess what could be causing this? My wife wants to rip out the entire bath tub and faucets and plumbing (as though spending several thousand $$ to fix this is no big deal. =( )

 

[Reach4]

I have yellow water that comes only out of the hot water of the mater bath tub for several seconds when I first run the water but not out of any other faucet in the house.

Can you access the plumbing to the tub via an access port-- maybe in the linen closet?

 

[Jadnashua]

Rust can cause this...as the concentration increases, it gets darker as things rust more. It might be a simple fix. Can you take the tub spout off? If you get it off, check to see what metal the feed tube is made of. If its steel, you may be able to unscrew it from the wall, apply a good dose of pipe dope, then screw in a brass one. If they used cast iron fittings, though, it will take more work. IMHO, one should never use iron or steel on potable water piping in a home. WOrks okay in heating systems, but not potable water situations.

 

[Standardairconditioner]

... I wanted to add that DIY's often forget internal pipe wrenches exist, it turns by expanding and gripping the inner i.d. of the pipe.

So when you remove threads roughs from the wall, don't jaw it with a Vise-Grip, which will make a mess of things.

 

[Copper]

I’m having the same issue. There’s no rust coming from the bathroom sink just the bathtub for a second or two but I always have to wash it out before filling the tub. I watched the rough in and a brand new Moen faucet set which included the rough in was installed. It’s very strange. This is an older home and all pipes under the house and going to faucets etc had been changed to pvc and fittings brass. Only the main is galvanized I was informed by the plumber but if it were coming from there it would be that way throughout the house I would think.

 

[Jeff H Young]

Could be just the nipple on tub spout is galvinized. change to brass . most of them are copper now but . this is a very common problem and still occurs so check that nipple its a 92.3 percent chance seen it many times. Sorry didnt read all the posts

 

[Stevenhong]

any update information, mine same

 

[Tuttles Revenge]

For years I worked at large plumbing companies that routinely used galvanized nipples and 90's for the tub spout, with the rest of the home being plumbed in copper.

This is likely what is going on. The tub spout was installed with a steel nipple rather than brass.

 

[Jeff H Young]

any update information, mine same

Gal nipple change to brass