New AGP plumbing with heater...shut off valves/unions?

Sep 25, 2018
57
NY
Hello! New guy here.

We put in a 30x15 AGP last fall and closed it immediately. I just opened it and used temporary connections to get the pool cleaned up and running, but I'm going forward with rigid PVC fittings and piping.

My question is, where do I need shutoffs, unions, or bypasses? It's a very simple pool, one skimmer and one return. Hayward pump/cartridge setup, and a Gulf Stream heat pump to be installed. I feel like i'm overthinking where I'll need unions and shutoffs, and Gulf Stream advertises using a 2" full flow heat exchanger which they claim eliminates the need to install a bypass.

How many/where do I need my valves??

Thanks!
 
Union valve just under the skimmer and right before the return.

If you cant easily get to the skimmer valve then another valve right before the pump.

I put a valve on the inlet and outlet of my heater. Never installed a bypass for the heater, thought I was going to but never did as I've never had the need to bypass it.
 
Union valve just under the skimmer and right before the return.

If you cant easily get to the skimmer valve then another valve right before the pump.

I put a valve on the inlet and outlet of my heater. Never installed a bypass for the heater, thought I was going to but never did as I've never had the need to bypass it.
I should have mentioned that there will be decking installed over the skimmer and return, so if possible I'd rather keep the valves where the slab is being poured, about 10 feet behind the pool. From what I can tell from your reply, that should be fine.

Thank you
 
You will still want valves right at the pool. Some day you will want to shut the water off at the pool. Its cheaper and easier to do it during the installation than it is after the fact when you really need them.
 
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JasonLion
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May 7, 200737,880Silver Spring, MD
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Having a bypass is required if your pump is very large relative to the size of your heater, which is rather rare, but sometimes happens when you have a single pump for both the pool and spa. The rest of the time having a bypass is only rather rarely useful.

You never want to turn water to the heater off completely for very long. The water left in the heater would "go bad" and then possibly cause problems when the heater was turned on again. Aside from the very high flow situation, the only real reason to bypass the heater is when you need to make the water very acidic for some reason.

You can get a very small efficiency improvement by partially bypassing the heater when it is off, but it requires a fair bit of automation and can damage the heater if you accidentally turn the heater on when it is bypassed.
 

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JasonLion
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LifeTime Supporter
May 7, 200737,880Silver Spring, MD
May 6, 2009
Having a bypass is required if your pump is very large relative to the size of your heater, which is rather rare, but sometimes happens when you have a single pump for both the pool and spa. The rest of the time having a bypass is only rather rarely useful.

You never want to turn water to the heater off completely for very long. The water left in the heater would "go bad" and then possibly cause problems when the heater was turned on again. Aside from the very high flow situation, the only real reason to bypass the heater is when you need to make the water very acidic for some reason.

You can get a very small efficiency improvement by partially bypassing the heater when it is off, but it requires a fair bit of automation and can damage the heater if you accidentally turn the heater on when it is bypassed.

Understood, but if I just open up the unions going into the heater and let it drain, I should be fine, right? I guess the only reason to ever bypass it for an extended period of time would be for repair.
 
My theory is, you should never have a reason to slam and as long as you keep your pH normal the heater is just part of your system. If you follow the CYA chart the bleach shouldn’t harm it even when you slam. I’ve read a lot of post from the experts on this site, because I had the same question. I also keep 200 calcium just because Heater Manual says so even though it shouldn’t make a difference but since calcium is cheap I don’t mind doing it and it stays there for a long time
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JasonLion
TFP Expert

Platinum Supporter

LifeTime Supporter
May 7, 200737,880Silver Spring, MD
May 6, 2009
Having a bypass is required if your pump is very large relative to the size of your heater, which is rather rare, but sometimes happens when you have a single pump for both the pool and spa. The rest of the time having a bypass is only rather rarely useful.

You never want to turn water to the heater off completely for very long. The water left in the heater would "go bad" and then possibly cause problems when the heater was turned on again. Aside from the very high flow situation, the only real reason to bypass the heater is when you need to make the water very acidic for some reason.

You can get a very small efficiency improvement by partially bypassing the heater when it is off, but it requires a fair bit of automation and can damage the heater if you accidentally turn the heater on when it is bypassed.
 
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