Water heater TPR valve should never discharge into the sink, tub, shower stall, etc. Emergency discharge of hot water / steam might cause severe injury. Keep the discharge pipe low, always pointing down and within 6″ from the floor level – you may also pipe it directly into the floor drain.
**Discharge **pipe from the water heater TPR valve **must **always run downhill - if the TPR valve opens occasionally, and water / steam instead of being drained, accumulates / floods the valve, it might eventually cause its corrosion, and prevent it from functioning properly or at all.
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