Wonder if anyone can help. Have the minimiser se ff60 boiler which is now discontinued. There is a whistling noise which starts after the boiler has been on for say one hour and it does stop and start again during the running of the boiler. Another forum had stated that the heat exchanger can get choked, do you think this is the problem and what do they mean by choked. The boiler is serviced every year. British Gas came round as it needed servicing and told me even before they looked at it that the heat exchanger would need replacing because we live in a hard water area and promptly signed me up for a boiler salesman to come round ( I think they get money for leads). In you opinion would this be correct
