I've got a old carpet cleaner that I sometimes use to clean carpets in rentals. I don't clean enough carpets to justify large expenditures for modern equipment.
My old rig is ok .... but has no heat at all. Frequently the rentals I service don't have power/water on to obtain hot water from the faucet .... so I thought about building a low-power solution heater.
If I take a 1000 watt water heater element and install it in a 2" diameter galvanized pipe, I can somewhat control the temperature with a water heater thermostat strapped to the pipe (set to 160F). Problem is, I need a (cheap) serial sensor to measure pressure and close the circuit only when the line has pressure (a no pressure reading means out-of- water).
What cheap water pressure sensor/actuator would work for this?