Baxi Duotec Combi - loud clanking noise from inside boiler

[bramish]

The boiler is two years old. From yesterday I've noticed a loud clanking like something heavy moving inside the boiler sometimes whenthe heating is on. When this happens I've turned it off.

Any idea what it might be?

Thanks.

 

[gas112]

sounds like a blocked heat exchanger

 

[bramish]

The central heating and hot water still work fine though?

 

[gas112]

The central heating and hot water still work fine though?

yep they would but the heat is not getting away as quickly as it should

 

[CountryFan]

Does the pressure rise to 3 bar? Does the pressure gauge go nuts?