It has to be the water heater, right?

[Robert Jones]

9 yr old home with a gas fired water heater. At the sinks throughout the home, the water pressure was fine on the cold water side, but nothing from the hot water side. The water heater was on(flame), and did have water in it. The branch line from the water heater was warm to the touch but no pressure when I tried to engage the tpr valve. What might cause this?

[Jim Morrison]

You probably checked this, but was the cold water feed to the water heater closed?

[Robert Jones]

It was open. I actually opened the drain valve and had hot water running out.

[Marc]

It was open. I actually opened the drain valve and had hot water running out.

Under pressure, or simply gravity flow? Try opening it all the way (if it's in the garage).

No escaping air velocity when you opened the TPR?

Marc

[Robert Jones]

Marc,

Simple gravity flow, typical Rheem gas water heater. Correct no escaping air or water when the TPR was opened.

[Neal Lewis]

It sounds like the water heater was only partially filled with water.

[Robert Jones]

SO it could be a faulty cold water valve. I couldn't turn it any further, so I assumed it was all the way open.

[Tim Maxwell]

I had one like that last week Rob.

The cold supply valve would just turn and turn in either direction I went in and I had not hot flow at any hot location.

[Marc]

Marc,

Simple gravity flow, typical Rheem gas water heater. Correct no escaping air or water when the TPR was opened.

Then it seems to me that the cold water inlet valve was defective or otherwise not open. If it was open, you'd feel the whooosh of the escaping air when you opened the TPR.

Marc