Yep, just had a look at the MI and the expansion relief valve is 8 bar, it's just that's unusually high. The max you usually get on the control set is 6bar.
I would recommend a service of the cylinder, as @muggles comment. It is important that these cylinders are serviced yearly, same time as the boiler would be the ideal.
I would recommend a service of the cylinder, as @muggles comment. It is important that these cylinders are serviced yearly, same time as the boiler would be the ideal.
