# Cerbo MK2 tank input bug or defect **URL:** \ **Category:** Q&A and troubleshooting\ **Tags:** expert, marine, cerbo\_gx, not-listed\ **Created:** [27 September 2025 21:15 UTC](https://community.victronenergy.com/t/cerbo-mk2-tank-input-bug-or-defect/46110 "2025-09-27T21:15:16Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![tobiaslochner](https://avatars.discourse-cdn.com/v4/letter/t/65b543/32.png) [@tobiaslochner](https://community.victronenergy.com/u/tobiaslochner)\ **Post date:** [27 September 2025 21:15 UTC](https://community.victronenergy.com/t/cerbo-mk2-tank-input-bug-or-defect/46110/1 "2025-09-27T21:15:16Z")
I’ve got a Cerbo Mk2 on my boat using the tank level inputs. I’m facing sporadic wrong %-values for my water tank. The sensor is 0-190Ohm and currently showing a reading of 31Ohm. This should be 16%ish. That value was shown for a couple of days, but then it’s drifting off. Currently it is still reading 31 Ohm but 63% of tank level. That is way off. Sometime I fill up the tank, the value is rising up to 92% an then it stops while the resistance is already at 191Ohm, so should be clearly 100%. I have attached two screenshot showing my current state. 31 Ohm reading, 0-190 Ohm configuration and a % reading of falsely 63%. Firmware is 3.66, so the latest (but this bug has been there for the last couple of releases as well), there is no custom shape etc. configured. I tried input 1 and 4 with same bug, changed the instance and checked the connections. After a reboot the % is back on track at 16% for the next couple of days, but starting to get off and buggy again. Is my cerbo faulty or is it a bug? Is this already known and is there a workaround? ![IMG_5492](https://europe1.discourse-cdn.com/victron/original/3X/5/9/59f9e9f59d7a4f00cd0dbbd9d1744f7d438ab0b7.png) ![IMG_5491](https://europe1.discourse-cdn.com/victron/original/3X/3/5/35c47641efabd0bdc100bc1efc425c47b905896f.png)