We suspect that there is too much pressure in the water system of a friend's house.
I checked the pressure regulator, the pressure gauge shows more than 4 bar (which AFAIK is way too much). However, there is water inside so it is probably no longer reliable.
I was wondering if there is a simple way to estimate water pressure (e.g. in bar) by filling a bucket of water (e.g. 10L) and measuring the time it takes to fill it?
EDIT : it's not from heater. It's a domestic water system.
EDIT2 : I did the following test: the main valve before the pressure regulator get closed and I opened the kitchen tap: the pressure dropped to 1.9 bar, which I think is excessive (I was expecting something like 0.5 bar). This indicates that the pressure gauge is damaged, probably due to the excessive pressure.
EDIT3 : I replaced the pressure gauge (the new one can go up to 10 bar). After replacement, it showed 4 bar. After some research, a leak was found in the basement (it seems fairly new). The leak was repaired and the pressure increased to 6 bar. I played with the pressure regulator (to try to lower pressure): no matter how it was set up, the pressure went up to 8 bar (which indicates that it was faulty and needs to be replaced too).