Jaguar Boiler - loss of pressure

[JohnL251]

I have a Jaguar boiler which is constantly losing pressure overnight resulting in a 'FO' message every morning. I refill the sytem and everything is OK until next morning when I repeat the process. The system is not leaking, however I have noticed that water is being dumped out of the pressure relief waste pipe.
Also after refilling the system and switching on the boiler, there appears to be a swirling sound from the pump as if there is air in the system.
Apart from this the boiler functions well - hot water and heating - any ideas

 

[Bahco]

Check the pressure vessel.

Read the FAQS.

 

[JohnL251]

thanks for that, how do I check it and what am I looking for?

 

[Bahco]

Read post 7 and 31. Your pressure vessels sounds suspect.