I am really struggling to get a decent reading from the Sika VVX20 flow meter that is part of our Ecodan installation. I think it would be best to get a dedicated flow meter that provides a digital reading and not an analogue voltage. I have a couple of questions…
I am aware of John Cantor’s blog post and will ensure that he meter is over sized.
it seems to me that the best (most reliable, accurate and easiest to interface with; though not the cheapest) is the Kamstrup when read via m-bus. Am I correct in this conclusion?
the documentation mentions the Kamstrup 402 and 403. Given that they all use the same communication method (mbus), can I in fact use any Kamstrup mbus meter?
Maybe not. My old pipework (where it isn’t lead) is ½" copper, yet the modern metric compression fittings work just fine. The reason is, 15 mm is the pipe outside diameter, whereas ½" is the inside.
The threads are still the same.
I bought one of them from Jon. When I saw the flow meter, my first thought was the threaded ends
appeared like they might fit a standard US garden hose. (¾ inch fittings/11.5 TPI) They didn’t.
The size was very close, if not the same, but the thread pitch was not.
So even if the size were to match what the OP needs, the thread pitch might be a show stopper.