Morning

I recently moved into a house with a heatpump, but something seems off. 

Heatpump will heat till set temperature of 55deg and then switch off, but as soon as the compressor stops the screen temperature drops from 55deg to 50deg.

This will startup the unit again, as soon as the compressor start the temperature jumps to 55deg and switch off again. 

And repeat the process again. 

Is there something I can check or replace?

1 hour ago, Brani said:

Temperature probe would be a first thing to look at.

Thanks, will this be inside the geyeser?