Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 7/11/2016

My shower head and tub faucet run at the same time. I have a 3 knob bathtub so can i fix it by myself?

Whenever I turn the middle knob to switch from tub to shower, the water runs from both the shower head and the tub faucet. Water pressure is low when both are running.

Do you have the same question? Follow this Question

1 Answer


By three-knob I presume the middle one controls flow to the tub spout or the showerhead - so if the seat (the gasket at the part of the valve that actually shuts off the flow to the spout) is worn or falling apart, some water will leak to the spout then the faucet is turned to shower. Water pressure is "low" because both are flowing at same time - probably drops off by about half if flowing about equally.

Commonly you can just (obviously with other two faucets OFF) remove the faucet handle (usually center screw holds it on) then unscrew the cover (bonnet or crown piece) on the center valve (being careful not to mar the surface - cover with heavy rag or sevearal wraps of tape to prevent tool marks) and then remove the bonnet and unscrew the valve stem - usually both bonnet and valve stem unscrews counterclockwise. What you get (the stem) looks like this typically (though lots of variations as shown) -

The bottom gasket or washer (usually held on with a center screw) is what makes contact with the metal "seat" inside the valve - which is the surface (with the gasket/washer) presses against which stops the water flow. If badly eroded from leaking the seat sometimes needs reaming - takes special tool which you can buy (though different shape for different model faucets) so not a usual DIY thing to ream it flat. Usually, if this leakage has not been allowed to continue for a LONG time, just replacing the bottom gasket/washer solves the issue, because it gets flattened out and eventualliy starts cracking with age. Good idea to replace the stem and/or bonnet thread seal gaskets as many as it has - sometimes up to 3) at same time - commonly on the larger plastic cores the rebuild parts come as a kit, on the all-metal stems usually you get individual parts at a plumbing supply shop or home improvement box store.

Just be certain when removing valve that you are undoing the shower/tub control one rather than hot or cold water (or shut of main water supply valve and drain down the hot and cold lines at a lower elevation sink to be sure), and open the center valve first to drain down any water trapped up in the shower riser, though if leaking significantly it should do that itself as soon as water is turned off.

For a professional, Plumbing is obviously your Search the List category - Handyman can probably do it fine too in most cases, but would have to go get parts whereas plumber should carry a washer and seal kit with him in his truck so probably about same bottom line cost either way - from around $100 in cheap labor area to $125-175 in higher cost areas to as much as $200-300 minimum service call in a very few very high cost cities.

If this is a fairly old installation (say 15-20+ years) you might consider having all three faucets rebuilt at the same time - probably same minimum service visit charge plus just a few more bucks for the gaskets/washers, because if the center one went out the hot and cold ones are probably about ready to start leaking too.

Answered 4 years ago by LCD

Related Questions

Terms Of Use
Privacy Policy