It is an odd position where I have an tankless water heater that has a 4' silicone tube coming off of a plumbing stub.
99% of the time, it feeds up into the mash tun to provide strike water and on-demand sparge water, it works perfectly for this.
1% of the time, when I want to do things like cleaning or am just being careless, I have to 'think' about the connection and make sure I dont kink it. If the water stops flowing out of it, pressure and steam quickly builds in the tankless heater and the input hose blows off. This is good because it is a quasi-fail-safe, as the water that is then streaming out of the hose is tap water, but the tankless heater will then begin to vent steam out of the inlet, and that is not safe.
This could be cured by additional copper plumbing, but my rig already has enough of that, or I could install some sort of flow sensor (but that still woudlnt prevent an over-pressure situation, just the steam hazard), but this is just such a simple solution that I want to go the strain-relief route.