Ideal Standard Hot Non-Return Check Valve — A963430NU
The Ideal Standard A963430NU is an authentic factory replacement hot-side non-return (check) valve cartridge assembly engineered specifically for Ideal Standard and Trevi thermostatic and manual shower mixers. Installed directly into the hot water inlet housing of the mixer body, this internal spring-loaded check valve prevents unequal-pressure backflow and hot/cold cross-over. Replacing a jammed or calcified check valve cures common issues such as cold water bleeding into the hot water supply system, uneven temperature blending, or system back-siphonage.
Identification Guide:
MPN: A963430NU | Legacy Barcode / EAN: 5055639184404 | Brand: Ideal Standard / Trevi | Supply Side: Hot Water Inlet | Function: Non-Return Check Valve / Backflow Prevention
Key Features
- Original Manufacturer Spec: Precision-moulded and calibrated to Ideal Standard engineering tolerances for dependable one-way flow sealing.
- Stops Cross-Flow: Prevents higher-pressure cold mains water from back-feeding into the hot pipework and domestic cylinder.
- Restores Blending Performance: Resolves erratic shower temperatures and fluctuating water delivery caused by a seized check mechanism.
- Complete Assembly: Pre-assembled cartridge core complete with internal spring, check plunger, and factory elastomeric sealing O-rings.
Fitment & Compatibility Notes
Designed specifically for Ideal Standard, Trevi, and Armitage Shanks shower valve inlet manifolds requiring a dedicated hot-side check valve:
- Valve Types: Compatible with select built-in (concealed) and exposed thermostatic shower valves across the Trevi and Ideal Standard ranges.
- Orientation: Designed specifically for the hot water inlet port assembly (paired opposite the dedicated cold check valve assembly).
- Verification Tip: Check your shower valve's technical parts diagram to verify part reference A963430NU or A963430 prior to ordering.