I got a boiler alarm on a steam boiler that showed a low water alarm when I arrived in the boiler room. I reset the LWCO and the boiler went immediately to a high water alarm. Closer inspection revealed water feed to condensate tank was running constantly and the condensate pumps were off. I tried to lower the level of water in the boiler only to find there was no water coming out of the boiler drain. Next I opened the relief valve and air sucked into the boiler and it began to drain. The condensate tank then filled with water to the proper level and the water feed shut off. Once the boiler water level was back to normal the boiler started up and seemed to operate normally. The steam pressure built up and when the level dropped in the boiler the condensate pumps started and filled to the proper level and then shut off. My problem is this has happened a couple of times at this location and I'm not sure why the boiler gets water logged after the initial low water alarm. Any help or suggestions about this would be appreciated. Thanks. Kev.