Not every downpipe fitting is about getting water into a tank. Blue Mountain Co sells two valves that solve different, specific problems on a downpipe — one is about water quality in a charged (always-full) line, the other is about bushfire defence and gutter access.
Wet/Dry Diverter Valve
The Wet Dry Valve 100mm ($72.80) automatically drains a charged line — a section of pipe that stays full of water between rain events rather than draining dry — to reduce the chance of anaerobic fermentation setting in. Stagnant water sitting in a charged downpipe or chamber line can develop odour and poor water quality over time; this valve gives that water somewhere to go rather than sitting indefinitely.
Fire Plug
The Fire Plug ($76.95) installs on a 90mm downpipe and does three different jobs depending on how it's set: close the valve and connect a hose to back-fill the downpipe and gutters with water as a bushfire ember-attack defence; divert water out via a hose connection for general use; or shut the downpipe off entirely while cleaning the roof and gutters, so runoff and debris don't go straight to the tank mid-clean.
Why these two are worth knowing about
Neither is a diverter or a filter — they're both valves that give more control over what happens in the downpipe beyond simple collection. The Wet/Dry valve is a water-quality fix for a specific plumbing condition (charged lines); the Fire Plug is a multi-purpose safety and maintenance fitting that's particularly relevant for bushfire-prone properties. Both sit in our wider Blue Mountain Co rainwater harvesting range, alongside the first flush diverters and downpipe diverters covered elsewhere in this series.
Frequently Asked Questions
What does a Wet/Dry Diverter Valve actually fix?
It automatically drains a charged (permanently full) section of downpipe or chamber line, reducing the chance of stagnant water fermenting and causing odour or water quality issues.
Can the Fire Plug really help defend against bushfire?
Per the listing, it lets you close the valve and connect a hose to back-fill your downpipe and gutters with water, which is marketed as an ember-attack defence measure. It's one part of a bushfire preparation plan, not a substitute for your overall fire plan.
Can I use the Fire Plug to shut off water while cleaning my gutters?
Yes — shutting the downpipe off with the Fire Plug stops roof-cleaning debris and runoff going straight to your tank while you work.
Does the Fire Plug fit any downpipe size?
It's built for 90mm downpipes specifically — check your downpipe size before ordering.