Siamp Storm 33A Adjustable Single WC Flush Valve
The Siamp Storm 33A is an adjustable single 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 | Storm 33A |
| Flush type | Single flush |
| Flow rate | 3.5 l/s |
| Adjustable height | 305 to 415 mm |
| Lid hole size | 18 to 50 mm |
| Cistern outlet size | 58 to 72 mm |
| WRAS approved | Yes |
| NF certified | Yes |
| Manufacturer part no. | 32335510 |
| 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. Remove the rose if the lid hole is under 37 mm or over 42 mm, and screw the button down without pressing its centre. Use no limescale or chlorine cleaners in the cistern.
Specification sheet (PDF) · Installation manual (PDF) · See related WC cistern parts.
