Engineers Give Me a Sad Sometimes

My mother-in-law just got in to town last night, this morning while I’m taking a shower the water goes cold. I know what this is. This too well not pass, not by its volition at least.
Our townhouse has an inline water heater. Amongst the multitude of safety features on it is a low flow detector. If at any point the flow drops too far, it stops pushing water which makes sense, it’s trying to alleviate the possibility of a leak dumping water everywhere at exactly one point in the water heading process. Except that’s not it acutely does, instead any time the flow is impeded too far, by the inline filter, it craps out. Rather than throwing a beeping sound or a warning message, I had to finish my now frozen shower and fuck around in the garage this morning.