That will be a bit of a job as the only bit of pipe I can get to between both stopcocks is this bent section coming up through the floor at the back of a cabinet and even that will be a mission without removing the dishwasher and housing. Everywhere else is out of bounds as the floors are boarded and have LVT on them. Could it be fitted after (or instead of) the house stopcock?
View attachment 421131
What I plan to do first though is replace both wc fill valves and maybe fit one of those shock arrestors.
It’s all been fine again since turning the water on and off. Does water pressure in the mains build up overnight?