Mark,

What kind of stop valve is this?

Harold,
Tell us more. What's this valve supplying and how old is it? Looks like a old angle stop to me. Cheers, Tom

Hi Tom,

See this post "Hey Plumbers" by monkfan,

https://www.askmehelpdesk.com/plumbing/hey-plumbers-597056.html.

She is having strange problems with water temperature in shower. I went back to previous post by monkfan and pull up that valve on her heater.
.

So I went back. What am I to learn from that? That it's a faucet supply? One more time. What's the valve connected to? Regards Tom

Monkfan's water heater.

https://www.askmehelpdesk.com/plumbing/hot-water-heater-mold-324292.html

I may be wrong but it sure appears to me to be a bleed valve... just like the one you can see on radiators...

Now we're all confused. Milo thinks it be off a radiator. I think it kind of looks like a old angle stop and you tell us it came off from Monks water heater. But how did Monks water heater come into play when his complaint was about a mixing valve and where did you get the picture? What am I missing here? Cheers, Tom

OK Tom,

I was reading monkfan's post about having plenty of hot water in the summer months and not having hot water in the winter months. I find that to be a rather strange thing. I noted that she made a post previously, about two years ago, about what she thought was mold on water heater pipes that was really tarnishing due to flux not being wiped off by the plumber.

In that post you noted that the plumbing was so bad that it could not have been done by a licensed plumber. I agree.

I also noted the stop valve used by the plumber. Having never seen a stop valve that looked like that I was wondering if it was just a stop valve or something special.

Now that Milo has mentioned it, it does look like a valve you see on heat radiators.
Just wondering if it could have anything to do with the strange hot water problems monkfan is experiencing now.

Hi guys... that is a vacuum relief valve, or just another type of anti.-siphon or backflow preventer.

In Massachusetts we are required to install these a minimum of 6 inches above the water heater in the cold water line to prevent the local fire department from sucking the water heaters dry when they purge fire hydrants or the neighbors fill their pools... that kind of stuff.

I think Monkfan's issue is a temperature balancing spool, but I am not 100% sure by any means. It seemed the best advice to start with.

Mark

Wow Hared!
You went back and picked Monks fathers complaint and then tied the two together? I'm totally impressed! Good job! Tom