Leaking water heater vacuum valve

[amazin6]

Hello all, I am trying to help my daughter far away from me. I searched and think I have found the correct part but not an answer on how to properly replace this vacuum valve. A few mentioned it may just be the O ring. Here is the part I think:
https://www.watts.com/dfsmedia/0533dbba17714b1ab581ab07a4cbb521/20431-source/es-n36-pdfAny ideas on the O ring to purchase?
I imagine if the water were shut off, it may just be unscrewed and replaced as long as there is something on the new threads of the valve. Is this correct? Thank you all.

 

[Twowaxhack]

Looks like the right part to me. They screw right in. Make sure you order the right size thread.

That pipe looks bad......

 

[Geofd]

Check your water quality,that tee is rotting from the inside, are you on a well or city water

 

[amazin6]

It is well water and she recently added a filtration system and water softener system from a reputable company.

 

[Twowaxhack]

It is well water and she recently added a filtration system and water softener system from a reputable company.

looks like she waited too long

 

[Twowaxhack]

I’d like to see a bigger pic showing the entire water heater.

 

[Geofd]

My brother in-law gets his water from a local,treated river, i think I've put in 4, hwhs
The don't last more than 5 years the ball valves deteriorate from the inside out told him he needs to test and soften

 

[Geofd]

Hello all, I am trying to help my daughter far away from me. I searched and think I have found the correct part but not an answer on how to properly replace this vacuum valve. A few mentioned it may just be the O ring. Here is the part I think:
https://www.watts.com/dfsmedia/0533dbba17714b1ab581ab07a4cbb521/20431-source/es-n36-pdfAny ideas on the O ring to purchase?View attachment 34088
I imagine if the water were shut off, it may just be unscrewed and replaced as long as there is something on the new threads of the valve. Is this correct? Thank you all.

That tee is actively leaking in the picture

 

[TomFOhio]

That vacuum looks fairly new to me in that picture. I would start at the water heater and replace that piping
including the tee fitting. We use to put them on commercial water heaters only but its been so long I can't remember
why without looking in the code book.

 

[Twowaxhack]

I only put them on bottom fed water heaters. It prevents the water heater from draining itself if the cold water line is opened.

Top fed water heaters have a hole a few inches down on the dip tube to break the siphon.

 

[Geofd]

I only put them on bottom fed water heaters. It prevents the water heater from draining itself if the cold water line is opened.

Top fed water heaters have a hole a few inches down on the dip tube to break the siphon.

It's code in mass

 

[Twowaxhack]

It's code in mass

On all water heaters ? But it being a code in Massachusetts doesn’t surprise me.

 

[Geofd]

On all water heaters ? But it being a code in Massachusetts doesn’t surprise me.

Yes they afraid of them siphoning and imploding

 

[Twowaxhack]

Yes they afraid of them siphoning and imploding

Don’t y’all have check valves at the meter ?

Sounds like they have a policy that requires every appurtenance known to man must be installed

 

[Geofd]

No check at the meter we have one of the strictest plumbing codes can't even install a faucet without a permit, money,money,money