Spa Jets Hayward Pump Replacement Questions

[Earthman Bob]

After more than an hour of looking up pump info, now I still need some help. I'll start at the beginning.

Our spa jets pump, which we inherited from the last owner of the house, froze. From the label, I think it was model SP1615Z1M. It was a 2 HP Hayward Super Pump. (The labels for the new motor and the old are attached below.)

So I began looking for a new pump, and bought another 2 HP Hayward Super Pump. This is the motor:

Hayward 2 HP Max Rate Pool Pump Motor - SPX1615Z1M - INYOPools.com

2 HP MAX RATE MOTOR - Pool & Spa Parts

www.inyopools.com

When I got the new pump home I realized that it had 1-1/2" inlet and outlets on the housing, whereas the original had 2" inlet/outlets. And that brings me to my questions.

1. Is it OK to use the new pump with the 1-1/2" ports on the new housing? Will it cause any major performance reduction? If so, I can use the old 2" housing with the new motor. I'd prefer to use the whole new pump/housing though and redo some of the plumbing that I need to do anyway to replace a broken check valve. (FYI, we won't be using this pump all that often, so while my first priority is usually efficiency, in this case, it's not that much of a factor.)

2. Is there any other reason why the new pump is not an acceptable replacement for the old pump?

Thanks for your cold-weather pool wisdom, in advance--

 

[mas985]

1. It is ok to use the smaller connections.

2. If you mean putting the new motor on the old pump housing, that should be possible.

Note too, that you could of just bought the motor and replaced that instead of the entire pump. Pump heads can last a lifetime.

 

[Earthman Bob]

1. It is ok to use the smaller connections.

2. If you mean putting the new motor on the old pump housing, that should be possible.

Note too, that you could of just bought the motor and replaced that instead of the entire pump. Pump heads can last a lifetime.

Hey Mark,

Thanks for the reply. Didn't see it till now, even though I've been looking. In the meantime, I contacted Hayward, and they simply said: "I would recommend using the housing with the 2 inch plumbing as the 1.5 inch will reduce the flow rate thru the system."

What do you think of that?

At this point I'm leaning toward using the old housing. I think one of the drain plugs openings in that old housing might be stripped though, so I'll need to fix that. Do you happen to know if there are any good ways of doing that? At the worst, I can just seal the plug completely, since I bring the pumps inside over the winter.

And yes, I could have just bought a new motor, except:
- The impeller on the old pump was broken too.
- The drain plug was stripped, as I mentioned.
- I got the new pump and housing in perfect shape for $275. So that's $50-75 less than a new motor would have cost. And once I sell the extra housing, it'll even be more.

Next time though, I'll just be replacing the motor. This was my live and learn experience!

 

[mas985]

Thanks for the reply. Didn't see it till now, even though I've been looking. In the meantime, I contacted Hayward, and they simply said: "I would recommend using the housing with the 2 inch plumbing as the 1.5 inch will reduce the flow rate thru the system."

Technically they are correct but practically, it will be a fraction of a GPM (<< 0.1 GPM) and not even perceptible. Save yourself some heartache down the road and use the new housing. It won't be an issue.

 

[Earthman Bob]

Technically they are correct but practically, it will be a fraction of a GPM (<< 0.1 GPM) and not even perceptible. Save yourself some heartache down the road and use the new housing. It won't be an issue.

That's good to know.

This pump/housing question got me reading about flow rate through various sized pipes, and I learned what you know already--that there's a big difference in the flow rate between 1.5 and 2" pipes.

1.5" = 38 GPM and 2" = 63 GPM

But that's running through an entire length of pipe. I'm guessing your (<<0.1 GPM) is because the constrictions would only be at the input and outlet of the housing.

Thanks for the help on this--

 

[mas985]

Those are recommendations for a water velocity at 6'/sec but are not absolute limits. They are meant for the main drain velocity to reduce the risk of entrapment so if you have 2" pipe to the spa MD, that is the target number. However, I suspect you are currently violating that anyway. Transitions at the pump really don't need to abide by those recommendations.

But it is a bit odd that you have 2" pipe for a spa. How many jets are on the spa?

 

[Earthman Bob]

The whole system, other than the Caretaker system that I had removed, was done with 2" pipe. This spa pump feeds 4 jets. There are another 4 jets that come from the main pump return.

As I mentioned, the original pump for the jets was a 2HP Hayward Super Pump. I tried a 1.5HP Hayward replacement on there before getting this 2HP pump. Granted that I don't know how jets are supposed to feel, but with the 1.5 they were not feeling as powerful as I thought they should. (Now there's also a place to put an air blower, but I haven't even delved into that yet. Learning one bit at a time )

And you got that right about the 6'/sec! I saw that reading here:

Pipe Size For Swimming Pools

www.swimmingpoolsteve.com

 

[ajw22]

Granted that I don't know how jets are supposed to feel, but with the 1/5 they were not feeling as powerful as I thought they should.

You feel water pressure not flow. Looking at HP and GPM is not going to tell you the pressure you will feel from a spa jet. What size eyeballs are on the spa jets? The smaller the jets the more pressure you will feel for the same flow.

 

[Earthman Bob]

You feel water pressure not flow. Looking at HP and GPM is not going to tell you the pressure you will feel from a spa jet. What size eyeballs are on the spa jets? The smaller the jets the more pressure you will feel for the same flow.

The eyeball openings on the jets are 3/4".

So then, given the size of the eyeballs, and the fact that there are 2" pipes feeding 4 jets, does that tell you something about which pump and housing would be most suitable?

I have both a 1.5 and 2HP Hayward Superpump that I can use and as you know, 2 housings with 1.5 and 2" inlet/outets. (I'll sell whichever I don't end up using.)

I had a sense that what I didn't know could be causing me to ask the wrong questions.

Thanks!

 

[mas985]

It is the nozzle that determines the strength of the jet and not the eyeball. The eyeball you can easily see but the nozzle is usually deep within the spa wall and not very easy to see unless you remove the jet assembly.

But it really doesn't matter. The smaller pump outlet will not restrict flow very much.

 

[Earthman Bob]

It is the nozzle that determines the strength of the jet and not the eyeball. The eyeball you can easily see but the nozzle is usually deep within the spa wall and not very easy to see unless you remove the jet assembly.

But it really doesn't matter. The smaller pump outlet will not restrict flow very much.

Now I know that there is such a thing as a nozzle. I'm reading about them...

I'll have to wait till the spring to look into what nozzles I have, along with what blower to use...

Seems like there's always something new to learn. And that's because there is!