Installation and upkeep of plumbing and heating: that is what this plumber can be asked about. Whether new equipment needs to go in or something already running needs a look, say what it is and which room it is in.
Before the visit, photograph the whole unit and take a close shot of the part that raises questions: pipes, a radiator, valves. If the heating knocks or makes other noise, record a short video with sound.
If it is not too much trouble, tell the plumber you found them on madloba.info.
✍️ If you have already used this plumber, leave a review on madloba.info: did they help, and how did the communication go? Your experience will help others choose.