Hello community, good morning! I go on to detail my problem, I rent a apartment that I am putting in conditions, it was about 10 years without inhabiting. The heating is with an orbis thermo-central, model 315/325 connected to 6 radiators in god plants, the pressure is with a 7/1 Rowa pump. Finishing the winter the pump broke, the official service told me that it had worked a long time without water, and it was destroyed, I found the float of the locked intermediate tank and the empty tank, change for the same 0KM model, also change the membrane of the low camera. Assemble everything, the pilot lights but the burners never start, the pump starts too. Remove the diaphragm and push the cylinder and the burners started. I think the problem is in the pressure of the system or air in it. Purge the pump as it says in your manual but some air remains in the sight glass. If anyone can guide me on how to purge the system I would appreciate it since I do not quite understand how the whole connection is. I leave a couple of photos of the thermocentral, the intermediate tank I think it is called, the spout of the tank enters the left side of the thermocentral Greetings, and thank you very much!

Thanks for the answers! In the end I had connected the pump to the right haha, I was guided by the position of the capacitor of the first pump and put the second in the same position, what I did not realize was that the address is marked in relief on the back of the bomb, it is seen that the first one had been disassembled and the capacitor remained on the left and I was guided by that. I also had a lot of air in the pipe, so I purged in the boiler with the butterfly mentioned by Walter and the rest of the radiators, I think I already purged everything and it's working 10. Thanks!