We have a Baxi combi boiler 133 HE Plus. It broke down after 14 months and Baxi are not being helpful. Our own engineer has repaired it but when the hot water turns on, the boiler whistles for about a minute which is irritating first thing in the morning. The condensate trap has been cleaned out several times and the printed circuit board was replaced (the PCB was blamed for the boiler breaking down). Any ideas as to why it should still be whistling please?

NB. I would not recommend any Baxi boiler. The boiler broke down after only 14 months and Baxi customer services are refusing any goodwill. 14 months for a boiler is not good enough.