While a normal toilet uses a tank full of water and gravity to flush, these pressure assist toilets have a small tank inside the tank in place of water. This small tank is similar to the tank in a private well pump. It has a rubber diaphragm in the middle of the tank. The water line feeding the toilet connects to the bottom of the tank and the water pressure pushes up on the diaphragm compressing the air in the upper part of the tank. When you push the flush lever it release the pressurized air and it flushes like a toilet in a commercial building. They are sold at Home Depot and yoi can even have Home Depot install it. It might be cheaper than having your plumber do it.
The second suggestion is to have a bottle or two of this product called Green Gobbler on hand. It can be bought st places like Walmart and Home Depot or ordered on Amazon.
https://www.walmart.com/ip/14691219721?sid=4af2d9ce-eb5c-4a34-9a94-a29886baa693
It is a heavy green liquid that you put into your toiled that clears clogs. It is like a specialized Drano (never put Drano in your toilet) for the toilet. Follow the direction and give it time to work.
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