American Standard single handle showers come in two generations with different parts. The older R110, R115, R120, R121, and R125 bodies (behind Colony Soft, Princeton, Copeland, Reliant 3 T385, Portsmouth, Ceramix, Moments, Town Square, Quentin, and Studio trims) use a 47 mm mixing cartridge in front of a separate pressure balancing spool. The newer Flash RU101 through RU109 bodies (behind Studio S and Reliant 3 TU385 trims) use a single pressure balance cartridge under a bonnet nut.
Before you start. Shut off the water at the house main (shower valves rarely have their own shutoff), then open the valve to confirm the water has stopped. You will need a screwdriver, an adjustable wrench or pliers, and for most handles a hex key (an Allen wrench, sold as an inexpensive set at any hardware store). If a shutoff valve will not turn or starts to drip, or anything is corroded and will not loosen with moderate force, stop and see when to call a plumber. New to this? Start here explains the parts and tools in plain language.
Not sure this is your faucet? See how to identify your American Standard cartridge without a model number, or how to find your brand and model.
Which parts
| Body | Cartridge | Balancing spool | Notes |
|---|---|---|---|
| R120, R121, R125 and the R110 / R115 family | 023529-0070A (47 mm), or A954440-0070A (ships with R111; has a built-in hot limit stop) | M952100-0070A | American Standard recommends replacing the cartridge and the spool together when the valve drips. The spool has a one year warranty. |
| Flash RU101 to RU109 with Studio S TU105 | M970654-0070A | Built in | Bonnet nut retained. |
| Flash with Reliant 3 TU385 | M970221-0070A | Built in | Double ceramic cartridge. |
| Older Reliant and Reliant Plus | 051091-0070A | ||
| Ultramix and Hampton | 066269-0070A or 051337-0070A kit |
023529-0070A at AmericanStandard-us.com. M952100-0070A balancing spool at AmericanStandard-us.com. A954440-0070A at AmericanStandard-us.com. M970654-0070A Flash cartridge at AmericanStandard-us.com. A954440-0070A at Home Depot. 023529-0070A at Home Depot
R120 family: steps
- Shut off hot and cold. Many bodies have integral stops behind the escutcheon.
- Remove the handle. On Princeton trim the set screw is a 2.5 mm hex from below; other trims use a screw under a cap.
- Remove the cap and escutcheon.
- Remove the two cartridge screws and pull the 47 mm cartridge straight out.
- The balancing spool (M952100) sits behind it. Pull it out and replace it too.
- Clean the inlets and the manifold face.
- Install the new spool, then the cartridge, and tighten the two screws alternately.
- Set the hot limit stop. The red ring on the stem is numbered 0 (hottest) to 7 (coldest); factory setting is 0. Pry it forward and rotate it counterclockwise one click to make the maximum cooler, clockwise to make it hotter.
- Reinstall the trim and handle, open the stops, and test.
Flash family: steps
- Shut off the water and remove the handle and trim.
- Fit the split washer supplied with the new cartridge between the ridge on the old cartridge and the bonnet nut.
- Unscrew the bonnet nut counterclockwise. The cartridge comes out with it.
- Insert the new cartridge and hand tighten the bonnet nut. American Standard specifies 12 Nm on first installation.
- Hot limit stop: a 1 to 10 scale where a larger number is colder. Turn the stem to off, pull the stop forward, and rotate it one number at a time.
Hot and cold reversed
R120 family: the 023529 cannot be flipped. American Standard sells a back-to-back version, 952377-0070A, for reversed supplies. 952377-0070A back-to-back cartridge at Home Depot. Flash: pull the pin and manifold and rotate the cartridge 180 degrees so UP faces down.
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