Guy in DC
Member
Could someone please advise how the boiler/ system pressure can be fixed?
Last Spring, a company installed a new Burham X-205 boiler with all other elements (zone valves, autofill feed valve, expansion tank). Three zones’ house: two for the aluminum baseboards and one for the large cast iron radiators (most 100 YO).
The last visit, the installer heated the system and when it reached 30 psi, drained around 1 gallon of water from the boiler so the pressure dropped to 20 or so psi. However, when the boiler doesn’t run (room temperature), there is no pressure, and, in all radiators, there is some air. I checked the pressure in the expansion tank, and it reads 12.5 psi.
When, it heats up, the pressure reaches 25 psi, and everything works fine. All radiators works and no air when I bleed.
My concern is that I don’t know what pressure, and its variation, I have in the system.
I read most of the related posts on this forum. In the past, Dana was very helpful to me with a similar problem on the old boiler https://terrylove.com/forums/index....r-system-plumber-in-washington-dc-area.85119/ , so I have some understanding: maybe the expansion tank is too small or maybe it wasn’t charged to a proper setting? If someone assisted with my measurement and questions, it would be very much appreciated.
In my house, the upper most radiator is 20 feet above the boiler, should the expansion tank be charged to 20ft x 0.433 = 8.66 psi and add around 5 psi so targeted around 14 psi? If so, it is almost what I have now. Would 2 psi make such a big difference?
I also consider changing to a bigger expansion tank: from #30 to #60. However, I am confused about the maximum acceptance volume: https://www.amtrol.com/wp-content/uploads/2022/05/MC4400_04_22_Submittal_Data_Book-37.pdf
It is said that an EX-30 tank volume is 4.4G with max acceptance factor .57 so 2.5G; and an EX-60 is 6.7G with .4 so 2.7G, respectively. Does it mean that the EX-30 can accept the same volume as the EX-60? If so, why to install bigger if the smaller is almost the same?
Thank you all.
Last Spring, a company installed a new Burham X-205 boiler with all other elements (zone valves, autofill feed valve, expansion tank). Three zones’ house: two for the aluminum baseboards and one for the large cast iron radiators (most 100 YO).
- The boiler was fed with cold water up to 12 psi as recommended by the installation guide
- The autofill feed valve was closed so no additional water is added to the system
The last visit, the installer heated the system and when it reached 30 psi, drained around 1 gallon of water from the boiler so the pressure dropped to 20 or so psi. However, when the boiler doesn’t run (room temperature), there is no pressure, and, in all radiators, there is some air. I checked the pressure in the expansion tank, and it reads 12.5 psi.
When, it heats up, the pressure reaches 25 psi, and everything works fine. All radiators works and no air when I bleed.
My concern is that I don’t know what pressure, and its variation, I have in the system.
I read most of the related posts on this forum. In the past, Dana was very helpful to me with a similar problem on the old boiler https://terrylove.com/forums/index....r-system-plumber-in-washington-dc-area.85119/ , so I have some understanding: maybe the expansion tank is too small or maybe it wasn’t charged to a proper setting? If someone assisted with my measurement and questions, it would be very much appreciated.
In my house, the upper most radiator is 20 feet above the boiler, should the expansion tank be charged to 20ft x 0.433 = 8.66 psi and add around 5 psi so targeted around 14 psi? If so, it is almost what I have now. Would 2 psi make such a big difference?
I also consider changing to a bigger expansion tank: from #30 to #60. However, I am confused about the maximum acceptance volume: https://www.amtrol.com/wp-content/uploads/2022/05/MC4400_04_22_Submittal_Data_Book-37.pdf
It is said that an EX-30 tank volume is 4.4G with max acceptance factor .57 so 2.5G; and an EX-60 is 6.7G with .4 so 2.7G, respectively. Does it mean that the EX-30 can accept the same volume as the EX-60? If so, why to install bigger if the smaller is almost the same?
Thank you all.