If it states that it is suitable for CH , than it should be ok for sealed systems ?? note the wording should be ?? normal max pressure on a seled system is 3 bars but the temp under certain circumstances could exceed 100 degs c , higher the temp , lower the pressure rating ,
(give the manu a call , preferably get any claim in writing (maybe ?)
Thats why all or most boiler manus do not want plastic pipe connected directly to the boiler !!!!! some oil fired boiler manus state in there MI's that plastic is not to be used at all , except in under floor applications , which will have its own thermo mixing valve therefore temp protection
(IMHO , maybe , possibly ect ect )