Fresh Start

[Alanspa]

Hello all
I purchased a home with a DIY in ground spa with 16 (yes, 16 jets on a 2 1/2 hp pump). And two swim jets on a separate return line.
No heater. 3000 gallon spa
I purchased a MasterTemp 400 NG and an Intelliflo 3 pump. (Yes, I know overkill on both heater and pump).
Reading installation manual and it says do not exceed 120gpm on heater. Pump is capable of 140 @ 88%. Pump comes with 3” outlet. I am reducing down to 2”.
Two questions.
1. Do I need to worry about exceeding gpm limit since I have reduced pipe size?
2. What is danger to heater from exceeding 120gpm through system?

Thanks for any input.

I will be posting more as I assemble this little beauty.

 

[HermanTX]

How much flow you actually achieve depends on your plumbing configuration. I have the Pentair VSF and only achieve 70gpm at full speed. It is unlikely that you will ever get to 120gpm.
To give you some piece of mind - build in a heater bypass.

Heater Bypass - Further Reading

www.troublefreepool.com

So you can heat your spa at a lower gpm. Then put the flow through the bypass to run all 16 jets.
You can also add a Flowvis flowmeter on your return line just to confirm your flow exiting your plumbing system

Flowvis Flowmeter 2"