Hi @flushing,
A warm welcome to the Bunnings Workshop community and thank you for your question.
If your Caroma Twinflush cistern continues to have the water supply pulsing on and off after you've replaced the outlet washer, the issue is likely related to the inlet valve or the seal within it.
Ensure the outlet washer is seated correctly and securely. The area where the outlet washer sits should be clean and free from debris. If the washer isn’t sealing properly, it may allow water to slowly escape, causing the inlet valve to refill. Inspect the washer for damage and test for leaks after reinstallation.
The pulsing sound is often caused by the inlet valve reacting to a leak or incorrect pressure regulation. Start by turning off the water supply and removing the inlet valve from the cistern. Check for blockages or debris in the valve or its filter and clean it thoroughly. Also, inspect the rubber seal inside the inlet valve. If it’s worn, replace it with a new one. Additionally, ensure the float mechanism is moving freely and not stuck. If necessary, adjust the float height so it shuts off the water supply completely when the cistern is full.
If the water level is set too high, it can reach the overflow pipe and cause constant refilling. Adjust the float or the water level screw on the inlet valve to lower the water level. Make sure the water level remains about 25mm below the overflow pipe to avoid triggering the inlet valve unnecessarily.
If cleaning and adjusting the inlet valve doesn’t resolve the issue, the valve itself may be faulty and require replacement. Inlet valves can wear out over time, and installing a new one often solves persistent cycling or pulsing problems.
Let me know what you think and if you have further questions, please don't hesitate to ask.
Jacob
