Issue with Astoria Gloria SAE 2

[Pappy21]

I had my machine completely service a few years ago for $900 and installed it when I finished by condo renovation. The machine fires up fine and the left head works well. The right head says flow meter error. The hot water button only pushes steam rather than hot water. I. have been using it with the single head for several months and it works fine. I had the service person from the company that overhauled come out but it was not the same guy and this guy seemed lost about what need to be replaced/fixed. I can try to do this myself if someone can provide guidance on what part needs to be replaced. Thoughts??