A large proportion of European boilers have fibre seal made of material called Fasit. Some boilers also use ‘O’ ring seals.
Majority of boilers sold in GB contain a booklet called the Benchmark logbook. The installers is required to enter data like burner pressure, temperature gradient, system cleanser used the type of inhibitor added to system water. This logbook can be a deciding factor for warranty claims. Annual services are also recorded here.