# Kamstrup Multical 403 Erratic flow readings **URL:** \ **Category:** Heatpump\ **Created:** [19 August 2023 12:29 UTC](https://community.openenergymonitor.org/t/kamstrup-multical-403-erratic-flow-readings/24206 "2023-08-19T12:29:46Z")\ **Posts on this page:** 1\ **Showing post:** 35
**Author:** ![Zarch](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/zarch/32/7947_2.png) [@Zarch](https://community.openenergymonitor.org/u/Zarch)\ **Post date:** [22 August 2023 17:37 UTC](https://community.openenergymonitor.org/t/kamstrup-multical-403-erratic-flow-readings/24206/35 "2023-08-22T17:37:25Z")
> [@ajdunlop](#): > > I also assume that reason the problem doesn’t happen until later in the hot water heat up as at higher temps that’s when more air bubbles are forming? @marko made lots of great replies in my Sharky thread about cavitation and air bubbles etc. Might be worth taking a look back through that? > [@Sharky 775 heat meter questions](https://community.openenergymonitor.org/t/sharky-775-heat-meter-questions/21591/86): > > E7 is air in flow pipe detected. Hotter water can hold less dissolved air. It will cavitate earlier. It’s also possible that entrained air in dhw is simply not clearing the coil ever. I can’t comment on plumbing other than to say this issue is nowhere near as prevalent in the district heading space. The manufacturer is following the mbus standard here so had already told you everything that you need to know there. The error values displayed are being incorrectly parsed by the mbus parser. Th… --- _[View the full topic](https://community.openenergymonitor.org/t/kamstrup-multical-403-erratic-flow-readings/24206)._