On another post someone said, if you release the pressure and turn off all the water into the unit that pressure should not rise. Unless of course there is a pinhole leak in the coil.Dallas wrote:If you have a domestic hot water coil in the boiler, it could be leaking water into the water jacket. The domestic line will be of a higher pressure.
OK, dropped the pressure in the unit. Then I closed off the inlet and outlet of the coil. Water pressure went to about 33#. Dropped the pressure again, opened both valves and closed the make-up valve. water pressure stayed the same. The entire time I was maintaining a temp of about 190 degrees. The expansion tank is new because the bladder got a hole in it, I"m thinking maybe water is acidic. Would also like to know what kind of pressure should be in the expansion tank. When I checked it after doing your test it showed 22# . Just another note, maybe this is a combination coil and reducer problem. When my wife turned on the hot water after the tests it was all dirty looking. Thank you for all the help so far.stoker-man wrote:You only have to turn off the water supply to the inlet and outlet of the coil. If the pressure remains within range, (boiler temperature will determine pressure), you have found your problem as a pinhole leak in the coil. Is your water acidic?
If the pressure still climbs, turn off the water make-up to the boiler and open up the coil again. The problem will then be in the pressure reducing valve.
Another potential problem is a broken bladder in the expansion tank, or a full ceiling-hung expansion tank. If the boiler is left to cool down, the pressure will drop.
Check these out and get back to us.
What was the pressure? zero or 33?opened both valves and closed the make-up valve. water pressure stayed the same.