Originally Posted by Wet_Boots
I want the blowout valve to remain open all winter, in case the indoor shutoff is not drip-tight.
There is still usually a drain valve at the shut off in the basement or at the elbow going up into the BFV. And I prefer it to stay open as well. Sometimes it's a boiler drain sometimes not. Sometimes the threads are cut off to make it un-usable, Sometimes it's the little thumbscrew cap at the shut off or on a cast ell or coupler, as this makes it meet code (even though someone could theoretically still hook up to it if they tried hard enough).
BUT - then when the valve is left open, and the lame gate valve doesn't shut off, then I get a screaming customer asking why there is water all over the basement floor. They insist it's my damn fault.