Disconnected heater hose & engine high Temp ?

The heater hose that feeds the heater coil for the dash heat has been plugged up by the prior owner because there was a leak. (It's plugged in the front of the RV by the heater coil.)
It looks like the heater coil received it's radiator fluid feed from the Engine Sending Unit. (Radiator fluid through Sending unit on it's way to heater coil)

Since there is no flow to the heater coil I assume there is no flow through the Engine Sending Unit?

Could this cause inaccurate water temp readings on my gauge?

I have been getting inconsistent higher than normal temps on my gauge.

Thanks for your help.
Jeff

'98 Monaco Dynasty - Cummins C-Series: 6 C 8.3 Engine Turbo - Side Radiator