Whistling noise while hearing up.
I have had my Linea Mini for about 2 years now. Just this week it has started to make a whistling noise while heating up. It sounds a bit like a kettle boiling, though more intermittent and not as loud. It usually happens a few minutes after I turn it on. It comes and goes, and once everything reaches temperature I don’t hear it anymore.
Everything seems to perform normally and I haven’t seen any leaks. My pressure gauges look normal too.
Should I be concerned?