Mel in North York

I have on and off hot water issue in my house. I have this REEM tankless boiler for 4 yrs. now, and we were satisfied and happy until this winter this year starts giving us on and off hot water. i called reliance 5 times and 5 differrent came over to check. They tried everything to solve the problem. They cleaned the filter, they changed the neutralizer for error 92 and the rest of the guys telling me its a plumbing issue. But they cannot tell me excactly what to do. I was feeling helpless because they always said there is no problem with the unit. I'm almost wanna give up and i decided to call reliance again and shows my disappointment. They told me that they are very sorry to hear my story and promised they'll send another technician. Finally this guy named SAM came, ask me questions, he called technical support to ask the required water pressure to this unit. From that point i was impressed and amazed thought that this guy knows what he's doing! He goes arround check connection of pipes ask me to open couple of foucets. And boom! He told me the problem, and explained me clearly well. It was check valve and flow peventer connected to my furnace. This guy has skill and knowledge to diagnose the problem that i didn't see from the 5 guys who came before him!.. Thank you for your service!