Re: A question for someone
Yes, there are 6 possibilities.
1) On the panel with the water and sewage tank guages. Usually in higher level models.
2) Built into the tank. More common on tanks which are fixed rather than removable.
3) Inline guages. These work on pressure, so I'm not sure how accurate/temperature dependant these are.
4) Auto switch manifolds. You probably have one of these. It has a green/red indicator to indicate whether the selected tank is empty or not empty. Also switches from the primary tank to the secondary tank when the primary is empty.
5) Tapes. These are LCD strips which tape to the tank. You pour hot water on them and read the level real quick. Never tried it and never had any interest in trying it
6) Magnets. These are LCD strips which stick to the tank by magnet. Supposedly shows the level if you get them installed right, but I never seemed to get a reliable reading with them.