Hot water heat question

[corndog]

Hi guys/gals,

I'm a bit of a greenhorn when it comes to these things - I have some basic knowledge of these subjects, but I am a little confused here.
Backstory: I am buying my first house and had an inspector go through it. The report came back clean, save the HWT. The house has been vacant for months, but they never turned the water off in the house. The inspector noted that the water is flowing out of this 'overflow' pipe out of the top, attached to the ball valve. Note it isn't the T&P relief. I am unsure why there would be a drain on what I presume to be the inlet of the HWT. The tank is 3 years old. I have attached some pictures, and hopefully someone can shed some light on this because I am
http://imageshack.us/photo/my-images/855/q9ar.jpg/
http://imageshack.us/photo/my-images/199/bq22.jpg/
http://imageshack.us/photo/my-images/11/jhr9.jpg/

 

[phishfood]

Though I have never seen one quite like that, I believe that it is a thermal expansion valve. A thermal expansion valve is meant to relieve the excess pressure that is created when a full (or nearly so) tank of cold water is heated and the water expands. If I am correct, replacing the thermal expansion valve should solve the problem.

 

[corndog]

Looks like you are right. Found what looks like that valve.
http://www.directindustry.com/prod/...hermostatic-expansion-valves-9063-686413.html
Water has been pouring through it since ~Jan, so I am guessing the current owners are going to have a monstrous water bill.
I just hope is a faulty valve and not the hwt.

 

[phishfood]

The water heater itself is not likely to be causing this.

 

[corndog]

Great. Thanks so much!

 

[speedbump]

I wonder where they thought that heater was going, having it strapped to the wall like that??? Or is this in the land of Earthquakes?

 

[corndog]

I wonder where they thought that heater was going, having it strapped to the wall like that??? Or is this in the land of Earthquakes?

Correct. West coast BC, pretty seismically active.

 

[chukar]

Thermal expansion valves were becoming required in water districts like burnaby, I like to use them as a trap primer. If your in BC lower mainland there is a 50/50 chance of even having a water meter. When I lived in coquitlam we didn't have a meter but it was part of the flat rate we payed to the city, for garbage and sewer.

 

[FML]

It's Thermal Expansion Valve Installed Opposite . The drain port suppose to towards the tank . ( so even if the ball valve is off & tank is on ,it still does its job )Saves pipes & tank from thermal expansion (extra pressure ) . These valves are usually adjustable(factory set under 80psi) . But before u think / check something else , Check your Domestic water Pressure .( PRV on main water Stop ). Raj ( Farid Mechanical Ltd .)