Brine Tank Overflow Elbow (P646)

The P646 brine tank overflow elbow is the fitting on the wall of a water softener's salt tank that carries away excess water to a drain point if the fill valve or air-check ever fails. Common to domestic cabinet softeners and commercial salt bins across Autotrol, Fleck and Clack systems, it's the part behind searches like "brine tank overflow pipe", "salt tank overflow fitting" or "water softener flooding fix". In stock at WrekinWater.

Technical specifications

Symptoms that mean you need this part

• The elbow is visibly cracked or has gone brittle — common on older cabinets where it's been exposed to salt and UV light through a lid
• Water pooling around the base of the brine tank with no other obvious leak source
• No overflow pipe run at all — sometimes removed or cut short by a previous installer

Why it fails / why it matters

This is a preventative part rather than one you'll necessarily notice failing on its own — its job is to stop a stuck float valve or blocked air-check turning into a flooded understairs cupboard or utility room. A broken or missing overflow elbow is very often the missing link between a minor fill-valve fault and genuine water damage, so it's worth checking (and replacing pre-emptively) even if it isn't actively leaking yet.

Why buy this from WrekinWater

It's a small, inexpensive part, but WrekinWater flags it to customers precisely because it prevents the expensive kind of call-out — a flooded cupboard rather than a £10 fix. 15 years of supplying softener spares to UK homes and businesses has taught us which £10 parts save people the most hassle. Rated Excellent on Trustpilot.

How to fit it

1. Bail or syphon off any excess water and clear salt sludge away from the fitting.
2. Unclip the old elbow from the grommet in the tank wall.
3. Push the new elbow into the grommet until it seats fully.
4. Reconnect the overflow pipe run to your drain point, making sure it has a continuous fall with no dips that could trap water and freeze.
5. Refill with salt as normal.