My toilets started burping occasionally and I couldn't figure out why. I called Clink on Sunday and got their voicemail. I left a text message and got a response within about ten minutes. I thought my tank was full, But the gentleman on the line quickly told me that it was probably a plugged vent on the roof. I climbed up there on the next day, and sure enough my roof vent was plugged with ice. One bucket of very hot water later, the problem was solved. He also suggested that I add a copper pipe that you simply drop into the vent to prevent this from happening further. They cost about sixty dollars at Menards, but I made one for twenty seven dollars.
THANKS CLINK!