With solar you need two check valves. One after the filter and before the solar valve. The second is for the solar return to prevent back fill when shut off. Those are a must.
I'm guessing that the Pool installer was thinking that the solar people will install the necessary check valves when I install the solar in a few months. I did ask him the question though (waiting for answer). Maybe he thinks that it comes with the solar. He did say that he's leaving a stub out for them though (3 way Jandy valve). I guess I have to make sure there is enough room for the check valves to be added after. Does it matter if I do it now or when the solar is installed?
The SWG doesn't really need a check valve because the chlorine levels never get that high (unlike a chlorine feeder) so it wouldn't cause any heater damage anyway. Plus with solar, the lines drain anyway.
Interesting. The salt cell now is just under 3' from the heater & the check-valve is right before the cell. I also thought the reason for the check valve was because of some sort of gas build up? I see from the Intellichlor installation manual it says allow 3' from heater & install before pool/spa return (which it is) to avoid gas traps in pipes. I guess that solves it. It also says if you exceed 80gpm, you need a bypass set up for the Intellichlor. I'm guessing that with 4 spa jets, I won't exceed 80gpm? And since it will only be that high when the spa is on, that I don't need a bypass set up?
I just checked a current RayPak installation guide & it shows in a diagram that a check valve is put in before the salt cell & says if an automatic chlorinator or chlorine feeder is used an anti-siphoning device should be used (I'm guessing that's the check valve) to prevent chemical backup into the heater when the pump is shut off. It also says not to exceed 60gpm or I need an external bypass. This would explain all of the existing check valves I have (one between the heater & cell & a vertical one between the inlet/outlet pipe). I would think the flow with the spa on is higher than 60gpm. Would the solar drain down solve the chemical issue here too or should I be better safe than sorry?
The only other place you might need one is for the spa if it is raised to prevent draining when shut off.
The spa is raised (12") above the pool water level - which is probably why the spa is draining down now - a check valve or valve is bad, which tells me that the spa will drain down in the new set up if there is no check valve.
You can do that with a two pump system too. And I don't remember saying that a single pump was best for solar. In fact, the opposite is true because of the high flow rate requirement of the jets.
How would that work with a 2 pump system? In the current set up, when I turn on the spa pump, in order for the solar to remain on the pool pump has to stay on. If I do that, than I'm heating the pool & spa, which I thought wouldn't heat up the spa fast enough or much at all because part of the water would be going back to the pool. If I turn the valve that makes all of the water go back to the spa only with the pool pump on, it would still overflow into the pool, although not like a waterfall.
You said, "the VS would require higher RPM when running solar but there are ways to reduce the RPM by strategic placement of the vacuum release valve (ie: a few feet above the equipment pad). Power is related to the cube of RPM so yes, lower rpm has a dramatic affect on power usage. But at some point, it just doesn't matter much. For you, the reason to go with a VS is ability to optimize for solar because a two speed would likely have a lower lifetime cost than a VS." You also said to keep the spa jet pump separate, but I can't afford the VS plus a new spa pump. I guess I thought if I was o.k. with my 1.5hp for the spa jets, that the VS wouldn't have to put out more than that for the spa & I was told by Pentair that the VS RPM at 1.5hp is lower than the RPM of my current Jacuzzi 1.5hp (I thought the same might be true for the VS at 1hp compared to the RPM of my current 1hp Jacuzzi pump) so I thought maybe it would all work & I would save a few dollars too. Am I totally off?
As for isolating the heater, I don't think that is necessary and doesn't offer any benefits.
o.k.
Are you putting in a filter, solar, heater bypass for the jets?
I'm confused here. Do you mean for the electric heater? If so, I don't think I will have a heater bypass (never had one, even when I had solar before) & only wanted one now because of the possible metal in the water issue. The VS will use the RP150, so as far as I know, when it runs the spa, it will go through it too. Solar will be installed in 2-3 months. When I put the spa on now (with my old 1.5hp jacuzzi pump), it goes through the RP150 & it raises the pressure to 20psi (which Pentair says is normal/fine for that filter). The jet pressure felt fine (although without a side by side, with & without the filter, maybe I'm crazy). Do you mean that there should be a bypass for everything? Like an actuator that turns so the water doesn't go to the filter when it is on spa? Why would I need a solar bypass? I thought if the VS was running everything, when you ask for Spa, the solar would stay on as the heat source (because I can program the easytouch for that) & if I want to change it, I can ask it for the heater?