It is must be 2 tanks... The drains are definitely not for the same tank - I did so compressed air tests.... Still confused about it and how to make it work. I draw it out and post. Thanks for anyones time who has looked at the tread.
Thanks for the help guys.... No not in Spain (northwest England) and I didn't test the coils. I got it secondhand from a guy in Southport, bought as a thermal store but he had no info on it. Me foolishly thought I'd easily find the manual online 😞
I've ordered a small camera so hopefully be able to work it out.
Thanks again