F+E tank with no vent

[Chalked]

Primatic cylinder.
The term 'Primatic' is a registered trademark of IMI.
Primatic cylinders perform the function of an indirect hot water cylinder with the primary services for a domestic heating system.


Primatic cylinders only use one supply cistern but functions as an indirect, automatically performing the duties of the feed/expansion tank in the double-feed system.


The working principle is based on the buoyancy of air; this considerable natural force is used to create the seals between the primary (boiler) and secondary (domestic hot water) systems.


Consequently, there is risk of cross-contamination between the hot water discharge and the central heating system, thus the use of treatment chemicals is not recommended.


If you only have one supply cistern, or your cylinder is marked Primatic, then you should not use treatment chemicals.

 

[tamz]

I think you may have a primatic system? Maybe?

How could it be a primatic with an expansion tank. Think about it. Google myson appollo install instructions (among others) and you will see a diagram. Btw the correct name for a primatic (which as the above post, is a trade name) is a single feed indirect.