We have an Aqua Magic Style Plus On occasion, when flushed, after filling the basin, the water sometimes continues to seep in causing an over flow. We replaced the seals and valve. Eliminating the...
Yes there should be a water pressure regulator. Mine is set for 40-50 psi. no more than 50. This could be your problem. If nothing else you could install a shut off valve in the supply line. My advice would be to replace the toilet with one of the new china models like maybe a Dometic 310. Almost like a residential crapper for under $200.00