cylinder change on johnson and starley j25-32 mk3 modairflow

[ahtplumbing]

Hi,

I have been asked to change a direct cylinder that is plumbed in to a johnson and starley j25-32 mk3 modairflow warm air. I was expecting to find a feed and expansion tank in the loft for this system, but there isn't one. Can anyone please tell me how I can drain down/refill the system so I can change the cylinder.

Thanks in advance

 

[ahtplumbing]

Sorry, I meant an indirect cylinder of course!

 

[PlumbersMate]

Pretty sure these are direct there is no F&E or CWSC on these, think they are mains fed

 

[ahtplumbing]

Thanks for the reply. So if I just shut off the mains and drain the water from the drain cock in the water heater opart of the system I should be OK?