It can always happen that something will be damaged or broken. If this is one of the larger repairs, you have to report this in the Huurdersportaal under the button “Reports”. You do not need to call Gruno Verhuur for this. If you will call Gruno Verhuur, they will always refer to the report section in the Huurdersportaal.
You only need to report damages which are not stated or mentioned as small recoveries. Some examples of small recoveries are painting of walls and ceiling, lose stair railings, door knobs, and shower heads. Also, easily replaced components such as taps, frames, locks, copies of room and front door keys, or replacing the door bell do not need to be reported. The Dutch government made a list of recoveries (original source) which are seen as small repairs. Large damages and repairs always need to be reported in the Huurdersportaal.
If you would like to know which costs are for you and which costs are for your landlord, please check this list.
P.S. : Did you know you can easily refill your Central Heating System?