Siamp Optima 49 Telescopic Dual WC Flush Valve

The Siamp Optima 49 is an adjustable dual flush valve for compatible ceramic or plastic WC cisterns. Its adjustment range helps match common replacement installations while the supplied actuation arrangement controls the flush from the cistern lid. Check the lid hole, outlet hole and cistern height before ordering.
| Brand | Siamp |
| Model | Optima 49 |
| Flush type | Dual flush |
| Flow rate | 3.5 l/s |
| Adjustable height | 282 to 430 mm |
| Lid hole size | 16 to 50 mm |
| Cistern outlet size | 58 to 72 mm |
| WRAS approved | Yes |
| NF certified | Yes |
| Manufacturer part no. | 32499910 |
| Pack quantity | 1 |
Measure cistern height (lid top to inside base) and lid hole diameter, then set the stirrup notch and cut the overflow to the table in the manual before fitting. Hand-tighten the flush valve nut to the ceramic and add no more than a quarter turn with a spanner — over-tightening damages the mechanism and is not covered by Siamp’s warranty. Maximum water level is 20 mm below the overflow; set the small flush by sliding the cursor. Remove the escutcheon if the lid hole is 38 to 45 mm. Use no limescale or chlorine cleaners in the cistern.
Specification sheet (PDF) · Installation manual (PDF) · See related WC cistern parts.