Anyone get Grundfos Direct Sensors working?

thoughtfulTom

Grundfos has a flow meter/temperature sensor product they call Grundfos Direct Sensors (there is a pressure/temp critter as well).



Resol (rebadged as Caleffi, SunMaxx, etc) BX and MX controllers can take in this data and give you BTU metering.



It is supposed to be super-cool. I've installed 6 of them, on three different projects, and not gotten successful results.



The problems range from obviously bogus data (flow at night on a drainback controller (virtually impossible - I have analog flow meters that confirm there is no flow), to more subtle problems like showing a flow that is incorrect (based on analog flow meters, and manual calculations of the increase in tank temperatures (which do not require the flow meters - so I have three ways of getting the information - two of which say Grundfos data through the Resol controller is bogus).



And the most fun: -888.8 ie the controller doesn't even recognize the sensor.



If you think I might be frustrated by these results - you are correct!



Now I did extend the wires, which Grundfos now says is not OK. So I may have caused some of these problems myself. But I have also installed using just the out-of-the-box cable and had all the problems above.



I am curious is others are having any success? (I have on installation that passes the smell test for being in the ballpark).



Feedback appreciated.



Tom