Dripping Shower Head when tub is being filled!

**Rod Gilbert** · 10-20-2010, 07:28 PM

Greetings folks!
This is not some monstrously challenging problem .... well, maybe for me ---- but I'm hoping there's an easy answer. Over the past few months I have found the shower head will drip, to leak, a tiny stream of water from it when water is supposed to be coming out of the tub spout. This is particularly true when the handle is in the warm position. There appears to be less problem in full hot, and no problem in full cold. First I assumed it was the spout and replaced it. The dripping continued. Then I was reading about replacing the seats and springs in the valve. Rather than do that I replaced the entire valve cartridge. The dripping still continues. This is a Delta unit Series 13/14 and was only installed less than a year ago. I have 1/2 PEX lines running to the valve and 1/2 lines run to the spout and shower head. Has anyone encountered this before and would anyone have any suggestions as to my next step. Clearly after tiling the whole bath and considering the bathroom completed, I'm hoping we're not looking at any drastic solutions!
Thanks in advance and patiently waiting any advice!!!
Cheers

**Rod Gilbert** · 10-20-2010, 07:53 PM

I can't believe I'm the one responding to my own thread, and I can't tell you how much I hate to state this but ....... I just found online in a Delta manual, a comment about NOT using PEX between the valve and the spout. Further searching revealed that 1/2 copper inside is larger than 1/2 PEX inside, and there's a reduction in flow which will cause water to rise! Does this sound like the culprit for my situation? I dearly would have loved knowing that when I was first plumbing the tub/shower. Unfortunately I was given the parts over a series of visits and never had the manual. I would still greatly appreciate any advice. If this is the problem, I have access to the back but haven't a clue how I would get behind the 2x4 cross piece and access the short PEX line!!!

**jadnashua** · 10-20-2010, 09:08 PM

The tub spout MUST be copper or brass, and not a plastic pipe, which, as you found, has smaller ID, and will cause the problem. Changing the line from the valve to the spout to metal will solve your problem. You can keep the pex to the showerhead, though. Now, how to replace it without tearing things up...that varies too much to have any single solution...you have to be there to tell.

**jimbo** · 10-21-2010, 06:22 AM

You already found your answer. There is essentially a direct connection between the tub spout and the shower. When you want to shower, the diverter on the spout blocks that outlet, so all the water goes up. When you open the spout for a bath, only the very low pressure at the spout outlet due to full flow, keeps water from backing up to the shower. Slow down the spout flow due to "too small " pipe, and you get water backing up to the shower. If the shower head is 4' above the valve, it only takes about 1.76 PSI to raise the water to the head.

**Rod Gilbert** · 10-21-2010, 05:33 PM

Thanks very much for taking the time to confirm my diagnosis and for explaining the reasoning! Much appreciated. I am curious though, why I don't have the drip problem when only cold water is coming out. Is it not the same volume of water coming out the spout or is it due to a pressure difference? Anyway, just curious. I think I can get at the PEX tubing and brass parts from the backside and I'm hopeful to come up with a plan to replace it with copper. My 10 year old daughter will certainly appreciate being able to fill the tub herself without getting soaked!!!Thanks again.
Regards

**jadnashua** · 10-22-2010, 09:40 AM

Take a bucket, and a stop watch, and measure the flow you get under different conditions...my presumtion is that when it is coming out of the showerhead, you will have more flow. COmbining both hot and cold should produce more volume than one alone.

hj · 10-22-2010, 06:09 PM

When both sides are flowing you will get more volume than when either one is flowing by itself. That causes the condition to occur.

**Bob_of_Maine** · 10-31-2010, 05:47 PM

Think of your problem as not really a problem.

The drip from the shower head occurs only when you are trying to fill the tub. If a bit drips from the shower it is all going to end up in the tub anyway. Unless you are interested in the pracice of ripping out and replacing the wall, and installing soldered copper tubing, you could leave it as is with no harm.

**Redwood** · 11-01-2010, 03:52 PM

I would callback the installing plumber and make him do it right!

Have a copy of the instructions handy and this link as well http://www.rif.org/

**Terry** · 10-19-2011, 11:42 AM

Here is a situation we found this week. The homeowner had hired a handyman to plumb her bath, who left her high and dry without completion. We went in to complete the job and set the fixtures. We found that the "handyman" had run PEX to the tub spout, forcing water out of the shower head above when the tub was being filled.

PEX can not be used on a tub spout in combination with a shower head riser.
Now the wall will need to be cut and the small section of PEX that acts as a reducer will need to be pulled out and replaced with full size pipe and fittings.

hj · 10-20-2011, 01:11 PM

I am not sure which is worse. Installing a valve without knowing the instructions, or hiring a handyman who does it without knowing how to do it correctly. At least they made your hole large enough to access the integral stops. I find very few where that is done, usually because the tile guys discard the plaster ground and then make the hole as small as possible so they do NOT have to make precise cuts.