Welcome to the forum. Although you can post in any forum, the USA forum is here in case of local regs or laws
It has to be pushed down after flush to reseal the cistern or else water just flows into the pan. It's part of a concealed cistern toilet and the valve sits into quite a tall cradle at the bottom of the cistern. Id happily get a replacement that would also fit the cradle. ThanksCan I ask what`s wrong with it?
Reply to the thread, titled "Identify flush valve" which is posted in UK Plumbers Forums on Electricians Forums.
We recommend City Plumbing Supplies, BES, and Plumbing Superstore for all plumbing supplies.