Yes they are, we’ve drained it down twice and put inhibitor in it both times. Both times it was full of crap, which I can’t understand in a closed loop system ???
It’s not plumbed up back to front but we’ve had the mixer valve off tonight and there was a loose oring and another “chewed” oring inside the mixer.
no idea where the loose one has come from, nothing of similar size where it could sit so we’ve take that out and put the chewed one back in until we can get a replacement.
since refitting the mixer the flow seems better but still doesn’t seem 100%.
Going to have to drain it down tomorrow and get the air out 🙄 but will see if the improved flow improves the room temps overnight.
-4 here tonight so I hope it can limp along for a few days 🥶