Hi Cam,

I don't see why you could not resurrect your wetback, there are a few things you will have to take into consideration though. Firstly make sure your Hot Water Cylinder is suitable and find out if your wetback is designed for indirect or direct water heating. To find out if your HWC is suitable for indirect water heating check the HWC manual. If you don't have that then give Rheem a ring and ask them, they are very helpfull. I have attached a picture to show how your HWC would look like if it was suitable for indirect heating (From the outside the indirect cylinder looks identical to the direct cylinder except for the two additional pipe connections on the side of the cylinder. Inside the cylinder a coil heat exchanger is installed, which allows hot water from the wetback to flow into the upper connection and leave at the lower connection to return to the wetback for re-heating. The hot water in the coil indirectly heats the water in the cylinder. having an internal coil no water will come out if you open one of the 2 extra inputs you mentioned, please don't open them though). Using the same method find out if your wetback will suit the type of HWC you have. (Wetbacks designed for indirect water heating usually have provision to bleed the system). I would recommend getting your wetback serviced before you fire it up! Once you have established that the two are compatible, connecting them should not be a problem. Your pressure pipe should be in copper and insulated also the great variety of brass fittings you can get at any plumbing supplier should make it easy to connect the two together. I'm assuming the two extra inputs you mentioned are vertically above eachother. Use the top one as the flow to the wetback and the bottom one as the return from the wetback. Also have a look and see if the wetback has an integrated circulation pump, this is required to circulate the hot water between the two.

I hope this helps to get you started .

Regards

Its my pleasure,  I would still check with Rheem though some cylinders are manufactured differently but can sill be used for indirect applications.

regards

You shouldnt be doing this kind of work unless youre a certified plumber....end of story.