Tank reading erratic, Marathon black tank

[Grizz]

The tank level reading for the black tank is erratic. Sometimes it's correct and sometimes the reading is falsely 'full'.

i understand there is a tube that gets plugged and can be blown out. Would someone fill me in on the procedure?

Thanks!

[Mikee]

The tube goes into the top of the black tank from the transmitter. usually on the curb side last bay back. remove the panel or cover and follow the tube back to the sender. Unhook from the sender and blow out with compressed air. Then reconnect and push the button on the sender for about 5 seconds. All will be good.

Mikee

[Grizz]

Okay, looked for it but on the black tank there is an electronic 'Honeywell' unit that looks to me, to be a sensor. It's mounted on top of a short section of white PVC pipe - top corner of the tank. No plastic tube can be found for that tank. Any ideas?

[Mikee]

What tank level sensors do you have? If you have the tube type there will be a box about 6x6x2 with a 3/8 plastic tube coming from it to the black tank. These units have a display using leds every 10 percent. Let me know what system you have.

Mikee

[Grizz]

It looks to me, like I have a combination system. I found the box and tube you mention for the grey water tank, but cannot find anything like that for the black tank. Not sure about the % readings on the Techlink screen, but I believe they are 10, 20 etc.