I originally posted this under heating, but think it might be considered a plumbing question.

Hi all,

Here's the short story: I am getting some water coming out of my pressure release valve on my furnace.

Here's what I know:
- The pressure release valve only goes off when the system gets to 30 psi, so it seems to be doing it's job.
- The amount of water released is very consistently the same.
- The "standing pressure" in the system is about 15 psi, so I'd guess that the pressure reduction valve coming into the system is working (and we even replaced that early on).
- I thought it might be the expansion tank. I took it off the system and it seems to be holding at 12 psi. It also appears to be the tank recommended for our system. However, just for the heck of it, I did replace the tank with a larger tank, which is preset at 12 psi (I did not confirm it).
- After we exchanged tanks I do see less water in my bucket in the morning (after the furnace has kicked in)

I have a two story house. Is my "standing pressure" of 15 psi too high?

I did discover that my Pressure Reducing Valve (Watts 1156F) can be adjusted, so I brought it down from 15 PSI to 12 PSI. The valve information says to determine vertical feet from THE VALVE to the top of the highest radiator. I was assuming you measured from the furnace. Given that, I'd say I probably go up around 15 vertical feet, which means that even 12 PSI could be a tad too much. Correct?

Thanks for anything you can offer! This will be my third winter in the house, and I am looking forward to not having to empty the bucket every morning!