Toto STRAINER,THERMOSTATIC TLT10 THP3123

THP3123 is a TOTO check valve strainer for a thermostatic valve, used on shower and tub applications. It sits in the hot and cold inlet path of the thermostatic mixing valve, where the check function stops cross-flow between supplies and the screen catches debris before it reaches the thermostatic cartridge.

Often, yes. A clogged strainer or a check valve that no longer seats lets hot and cold cross over or starves one inlet, and the thermostatic element reacts by swinging temperature. THP3123 is the check valve strainer for the TOTO thermostatic valve, so swapping it is the normal first step before condemning the thermostatic cartridge itself. If temperature still wanders with clean, freely seating checks, the problem is in the cartridge.

It's a repair part, not a valve body. THP3123 is the check valve strainer component only, so you still need a working TOTO thermostatic valve and cartridge in the wall. Ordering this expecting a full valve assembly is the most common mistake with this number.

No. THP3123 is a TOTO service part matched to TOTO thermostatic valve bodies. Check valve strainers are brand and body specific in thread, seat depth, and screen diameter, so it won't seat correctly in another manufacturer's valve. Identify the TOTO valve model in the wall before ordering.

A thermostatic mixing valve has a hot inlet and a cold inlet, and each one carries its own check valve strainer. Plan on two per valve unless you have confirmed only one is fouled. Property managers rebuilding a run of identical TOTO thermostatic showers usually buy in pairs for that reason.

Order it as TOTO THP3123. That is the manufacturer part number and the single orderable configuration of this strainer, so there are no size or finish choices to specify with it.

You can flush a screen that is simply loaded with scale or construction debris, and on a new install that's often all it needs. What you can't restore is a check that no longer seats, usually from grit scoring or a relaxed spring. If the shower crosses over, meaning hot shows up at the cold side with the valve off, replace with THP3123 rather than clean.

No. The check valve strainer lives inside the valve body behind the wall and is never seen, so trim finish has no bearing on it. THP3123 is supplied in one configuration regardless of whether the escutcheon and handle are chrome, brushed nickel, or anything else.