Recent content by Guy in DC

Hello, My 11YO Unico (indoor)-Rheem (outdoor) high velocity system needs to be replaced. The Unico coil leaks, so I consider changing both indoor and outdoor units. I am getting quotes and I am overwhelmed. More I read – I am more puzzled, so your comment would be appreciated. First contractor...

Thanks again John and Fitter30. I replaced the expansion tank for EX90 and no pressure issue anymore. When the system is cold, the pressure is 14psi, when reaches 180F, the pressure increases 20-22 psi.

Hi Fitter, There is no old parts that I can find. However, the system was alternated: the cast iron pipe are around 3.5 inch diameters, which were cut and connected to 1 inch copper connected from/to a boiler. Anyway, I ordered much larger tank...

I looked at the ceiling and there is no marks and I doubt it was patched since the ceiling looks intact. Maybe it was located on the floor?

Thank you very much John!

Thank you! I wouldn't worry much about the pipe bursting then.

John, if you refer to the pressure relief valve opening I described in the old post, it was a different issue: the autofill valve was broken. Would you advise to change the extension tank for a larger then? Also, someone told me that the entire system was not properly vented so I might have...

I am looking at the old boiler: the tank and the pump were installed in a return pipe. Does it make a difference for the size of the expansion tank?

It was a 2G tank. The previous boiler (with pictures are in this post https://terrylove.com/forums/index.php?threads/a-hot-water-radiator-system-plumber-in-washington-dc-area.85119/ I think that the boiler was max 150-160K BTU. It was installed in the house early 90. The new one is smaller...

Thank Fitter30. Previously I had EX-15 2G and it worked fine. However, as John suggested, it was a different configuration and the pump was smaller.

Thanks John. I will go for a slightly larger tank allowing more space when expands. I've just called Amtrak and the tech calculated the proper tank - they recommend EX90. You mentioned - Would it hurt the system and the pipes if the pressure is continuously high (meaning around 25 psi). Coming...

Neither indirect or coil. Before, the expansion tank was at the return size, if it is matter. the pump was directly mounted on the boiler supply. For the the expansion tank: I can change from #30 to #60. However, I am confused about the maximum acceptance volume...

John, one more question: 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?

I thought about it and will do as suggested.

I don't know exactly what the system volume could be. I assume based on large cast iron radiators, pipes, around 200 gallons. Before replacing the boiler, the expansion tank was #15 (and I changed to #30) and it worked fine. The pressure was 12 psi when cold and ~20 psi when 170F.