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Dual-flush retrofit clears the bowl inconsistently
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How can you tell whether a dual-flush retrofit valve is a poor match for a toilet, rather than simply needing an adjustment? The issue I’m most curious about is incomplete bowl clearing that leads to repeat flushes, not a slow tank refill.
Would knowing the toilet model and the retrofit valve model be enough to check compatibility against the manufacturers’ guidance? And what would a plumber look at to assess flush performance before deciding whether to adjust the valve or put the original parts back? I’d rather not assume the retrofit saves water if it takes repeated flushing to clear the bowl.
2 replies
The model numbers are a useful starting point, but the flush test can help separate an adjustment issue from poor bowl-clearing performance. A plumber can check whether the valve delivers the flush volume it’s set for, then observe whether the bowl’s water spot clears and the siphon action completes. If the flush volume is right but the bowl still doesn’t clear reliably, more valve adjustment may not help; comparing the toilet’s performance with its original parts would give a better basis for deciding whether to keep the retrofit.
The two model numbers are a good starting point, but they may not settle compatibility by themselves. The manufacturers’ notes may also specify the flush-valve opening size, tank depth, or an operating range the retrofit needs. If the toilet falls outside one of those published limits, that could rule out the retrofit before anyone tries further adjustment.
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