I've got one where rad pinholed and lady poured leak sealer into rad not thinking it would be introduced into boiler and rest of heating system... She has got away lightly so far but I've had to drain out the tank manually back flush with mains pressure and manually descale the pump and the 3 port valve. 🤞 The boiler seems ok but the heating is not in use yet so we will wait and see.
F and E tank was full of a cottage cheese kind of substance I can only assume was the leak sealer mixed with inhibitor.