High water bills are usually caused by some plumbing fixture in the house that is malfunctioning. The most likely culprit is a toilet. Whether the symptom is a toilet “running” continuously or “turning on” for several seconds at random, both of these will lead to an increased water bill.
It is almost always a fixture or device that is not turning off completely. A faucet that runs very slowly because you can’t turn it off will increase the water bill if not repaired and left as is for days or weeks. If you need help locating or of course repairing the device, call me to schedule a visit.
If it is a faucet that will not turn off completely (dripping from the spout), first watch my video “Cartridge Faucet ID” then call me. If you have a washer style faucet, and you want me to try to repair it, watch the video “Washer Style Faucet Repair” anytime prior to my repair visit.
Once I discovered the leak was a malfunctioning humidifier attached to the furnace.
If you have an irrigation system and there is a leak outside underground this rare event can increase your water bill.