Copper pipe coming off 325K btu heater... (SWG replumb)

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Very simple problem/question:

I'm going to install a RJ-30 circupool saltwater chlorinator on this pool. It needs about 7"+ cut away from the return pipe to fit in a set of elbows to attach the chlorinator cell. Pictured below is my dilemma. The return pipe is the one going to the top jandy valve, the shorter copper pipe with the dip, then PVC changeover, etc.

The PVC segment of that line is just a hair short of what I likely need (around 6 1/2" - 6" if including room for the elbows). I've never attempted to work with PVC-copper, but plan on it here. First, how is the PVC connecting to the copper judging by this picture? That is 1-1/2" inch line, and my circupool needs 2" elbows pointing up. What is the recommended solution if I need more room? Should I just replace the whole copper pipe with PVC? Is that even possible? (ie, this is a Laars Lite 325k BTU heater vintage 1998 or so) Or does the heater require copper come off of it? Any special fittings required if I go PVC directly off the heater?

poolpipes.JPG
 
The PVC/copper fittings are threaded. I wouldn't recommend going directly against the heater with PVC. You're going to have to some soldering, if you're not familiar with it you might want a professional doing that part for you.

Here's what I would do.
Cut the top copper pipe (in relation to the photo) about half way between the heater and the elbow and solder on a 1.5" threaded male adaptor.
Then start at the valve and plumb the cell housing in and then on to the threaded adaptor with PVC.
 
Went to home depot and found the fittings. Getting a little more comfortable with this.

Should I shorten the copper near the top (before the elbow under section) and do the 'elbow under' in fresh PVC? or should I shorten the copper after the elbow under ? If I cut near the top [ie 12 inches after exit from the pool heater], I can more easily do this without removing the whole section (off the pool heater) to have more room.

Is there a minimum length of copper I should have coming out of the pool heater?

I've never done torch soldering of copper before, but found a 'copper epoxy' product for much cheaper than solder+flux+torch. I figure if it fails, it will be outside and I can easily redo it. Its not as if it is high pressure. Any ideas on this product?
 
The purpose of the copper is to dissipate the heat before it comes in contact with the PVC. CPVC (designed for high heat conditions) fittings were not in wide use when your pool was installed. You could cut the copper as short as 6 inches if you solder on a male adapter and connect to a CPVC female to gain space. The old rule of thumb is male metal to female plastic for heat sensitive connections. If you have controls that allow for a cool down period after the heater has shut off the dissipation of heat is not as critical. Hope this helps.
 
Ah. I noticed Home Depot doesn't have a CPVC adapter. What sort of thread sealant (teflon tape?) should I use between the CPVC and copper?

Could I get a CPVC pipe to go straight from the heater instead of copper? If I did, what size would I use? 1-1/2" or 2" ?
 
That copper plumbing is going to cause you problems. I would go even closer than Bama and make it a 4" stub and sweat the male adapter on, then Schedule 80 to the salt cell. If you go to a plumbing supply instead of H-D, you'll find what you're looking for. Bet the service there is better too!

While you're there, ask if they have replaceable bondable sacrificial zinc anodes you can put in just before the cell. It will pick up any stray currents that could otherwise attack the unbonded copper pipe.

Scott
 
The cast iron flanges you have are designed to squeeze a gasket around the smooth copper piping or recieve a male adapter. If the threads are in decent shape you might be able to thread in a male CPVC fitting but I would question this connection in a high heat conditions because of the expansion/contraction ratios of the metal and plastic. Your heater is pretty old and dissassembling that joint and trying to change it could become a tough fix. The gaskets between the flange and heater may or may not be available? If you can afford a new heater that would be the best solution.
 
So is the copper epoxy in a high heat environment a definite no-no ? It is marked fine for hot water systems.

I don't want to re-invent the wheel or have to end up replacing the heater, as I barely use the heater (twice or three times a year?) so I am weary of throwing in a male CPVC fitting directly into the heater. The threads on the inside of the heater do look "virgin" though. Also, even if I go CPVC, how to do then connect to PVC? Should I go from the male CPVC nipple (1 foot from the heater) to a female PVC and some pipe tape? In the end, very hot water comes out of that heater and the 1" of CPVC doesn't dissipate anything (relative to copper). Endgame: I still have hot water stressing the PVC side of it, even if I put a CPVC elbow/slip fitting. And isn't PVC cement incompatible with CPVC? Is CPVC cement compatible with PVC? [never worked with the CPVC side] I might as well keep the copper.

I looked on the old copper-->PVC connection (both are reinforced with those steel tension grips), and on the long straight one in particular going towards the heater input, there are signs of fracture stress on the PVC. That seems strange to me as the hottest water would be coming out of the line I'll be working on. There is very little heat stress damage on that one (maybe the elbow helps?). Those copper pipes you see are at least a decade old.

About the sacrificial anode, where would I place it? My heater is already connected to the bonding wire. Should I run the bonding wire to the copper pipes themselves additionally?
 
Sorry but I know nothing about copper epoxy. IMO you should solder or epoxy? a male nipple onto the copper and use teflon tape to connect it to a female CPVC and that point use compatible glue to regular PVC. I don't see the need for sacrificial anodes in this situation.
 
If you lose the coper pipes, you can skip the anode. The pipes are insulated from ground so any stray current left in the cell would attack it. That would thin the walls and send copper in the pool. Eventually, you'd have a leaky pipe.

I would be surprised if Jandy didn't still have parts in distribution for these heaters. Subsequent heaters used similar parts.

Scott
 

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Scott, the copper heat sinks are the anode in this case and have been in place for many years. Any stray current issues don't seem to be a factor. If you remove them the heat exchanger becomes the least noble metal in the system and therefore the anode.
 
Renovxpt,

The exchanger is attached to the bond because the heater is attached to the bond.. The copper heat sinks are isolated from it by the gaskets. It won't hurt to put a zinc in place if he removed the copper plumbing but I don't think the exchanger has a concern. The unbonded copper plumbing is where my concerns lie.

Scott
 
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