Alarm clock boiler - BAXI!

[Corin]

Recently having my wall hung Baxi boiler serviced, the plumber flushed the sytem and put some inhibitor into the system. Since doing this, on heat up from cold for both hot water and central heating, it makes some almighty noises! And first thing in the morning this is worse than an alarm clock!

The boiler is in good condition even though it is 16 years old.

Any advice/tips?

 

[Kristoflampie]

Systems can make a lot of noise if they havent been vented properly when they are refilled, assuming it all worked before stop the entire system and bleed all the rediators from the bottom of the house upwards this includes the pump and boiler being free of air as any air gap in the boiler water will allow it to boil , air in the pump causes air locking and poor circulation. Hot water cylinder coils require bleeding where possible. The noise is caused by the effects of poor circulation and very hot water mixing with cool, check that any single radiators with 2 ordinary valves are open as they provide a circulation path for older systems. They are usually in a bathroom or hall and provide a path if TRVs shut down in this warmer weather.
Hope this helps, its not a definitive answer but its what I would look at first, then make sure the pump is doing its job properly, good luck

 

[ChrisR]

Even with all the air vented, old boilers do do that sometimes after a flush. The get a bit better slowly, and "Boiler Silencer" helps. That's an elixir you pour in to the header tank having emptied it through a drian cock. Results are very variable.