I have a 12 year old Aker MAAX bathroom spa that recently lost a wet end. I decided to replace the entire pump rather than mess using the original motor.

The spa was installed when the house was built and never had any access to the pump. I did finally get the old pump out by cutting a hole in the wall but wanted to mount the new pump in the basement under the spa to isolate the pump noise.

Balboa told me that my original 1 HP Olympian Mark III pump was rated at 50-60 GPM at 10-12 PSI. I purchased a new 3/4 HP WOW pump rated at 86 GPM since it was going to be mounted in the basement under the spa.

I installed the new pump no more than 2 foot beneath where it was originally mounted yet the flow to the jets is not as it was with the original pump. If I close down half of the jets the remaining work well.

So I'm now assuming that these spa pumps don't work well if they have to pump water to a 2 foot rise or do you think that there are other problems involved here?

Is it possible to find a pump that will match my needs or should I bite the bullet, cut a larger hole in the wall and mount the pump under the skirt where it originally was?

 

I don't think the elevation is a big issue since you are raising water up hill. How did you plumb in the new pump? In a high velocity system the number of bending fittings, especially 90 degree ones can really kill the flow rate.

If remote mounting the pump it can help if you use flexible tubing instead of rigid so you have nice sweeping bends and not sharp corners. You can also up-size the plumbing. Larger size tubing will allow the water move slower so what turns & fittings you do have will carry less a penalty.

 

more than likely the newpump has no head. This means it won't pump up very far at all. you will need to look into head, what it will pump at the height of highest jet to pump.

 

I did use the flexible PVC to eliminate as many ells as possible.

Balboa sent me an email that said these pumps were not designed to pump to a head. Said the pump should be fine if moved under the skirt.

BTW This Balboa pump is quiet.

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I remember having a Jacuzzi hot tub on my deck years back and wasn't happy because it cooled so quickly once we removed the cover and started the air blower in the winter.

I cut the PVC and routed it to the inside of the house where I connected it to a new gas boiler that did a wonderful job of keeping things toasty warm. And the jets never suffered from the extra pipe or boiler. I guess things are different now.......

 

you could change pumps if you really want to keep it below or are you going to move it up?

 

How do I find out what type of pump I need if it remains in the basement? I am not opposed to purchasing the right pump.

 

accurately measure the distance from pump to highest jet. This will be your head, pumps will have a graph of what they will pump (gph) at what head. So you will need to match one up to what gph you want pumping out of jets. Remeber depending on how many jets there are you might want to get a pump that pumps a little more to accomodate all jets.

 

Try and find the performance chart for a pump you are considering. Some list their maximum head/pressure (the pressure/height the pump can push water and no more) and maximum flow (the flow with no head and no plumbing restrictions) which is somewhat useless. You need to know how much water (gpm) the pump will move at a certain head. Many online pool and water fountain, waterfall websites have calculators to figure how much head equivalent lengths of tubing and fittings adds. Even though your pump is located below the tub it's not actually elevating water (it's just moving it around) so the head will be zero and the loss to the plumbing will generate your head required number.

 

Well that was a total waste of time and money....

I was told by Balboa that my original 1HP Olympian series pump was rated at 50-60 GPM 10-12 PSI. Since the new pump was going to be moved to the basement I purchased a 3/4 HP WOW pump rated at 86 GPM.

Once installed performance at the jets was disappointing.

I contacted Balboa who told me that these pumps couldn't handle any head whatsoever and that the pump needed to be moved back under the skirt of the spa. I was told that the new pump should be more than adequate to do the job expected.

So I relocated the pump under the skirt of the bathroom spa and yet the performance still suffered.

If I close down two of the main jets the rest immediately improve. To me, it still seems as though the pump isn't moving enough water to please all the jets at the same time. I have also noticed that since performance is lacking that air isn't being injected into the spa nearly as well. I'm assuming here that the flow needs to be strong enough through the jet orifice for the venturi to suck air correctly.

What do you all think, is there any way to determine the spa's actual needs so I can purchase the correct pump?

 

there is ways to figure it, pump manufacturers should be able to help. You will need to know plumbing size, how many fittings, how many jets, the exact head if you plan to put pump down stairs, and how much action in the tub you want. Probably going to need a medium head pump.
Keep in mind the pump and lines to pump will stay full of water after draining tub.

yes the flow must be sufficient to pull air into jet.

 

Thought about that standing water problem already. Have a 24 volt solenoid that I was going to activate on a 20 minute timer to drain the lines if the pump was installed below the spa. A standard air button/spst n.o. push-button switch could initiate the timer sequence.

 

Do you think this would work if I installed a medium lift spa pump in the basement with a GPM of roughly 100 or so. I could then use a ball valve on the output of the pump and also have a bypass loop with a second valve in the basement. That way I could tweak the flow rate to the spa and by throttling the bypass not overwork the pump.

I appreciate the help you guys have given me

 

good thinking on draining lines, post the info I talked about in previous post, I'll se what I can figure out.

 

There are a pair of each of the large jets (4 total) and 4 additional of the smaller spinning micro jets in the spa. (8 jets total) Picture is attached

The spa has 2 returns and has 2 air controls.

Do you also need a fitting, elbow, straight pipe length of everything under the skirt as well as any pipe/fitting that will be added in the basement?

 

yes, as close you can get and the gallonage and size of tub. When you say returns, what do you mean? The jets are a return.

 

Returns = suction

I'll get a fitting count later today and post back.

 

Here's what I came up with for a total system count. I kept the suction count separate from the supply count not knowing if it made a difference or not.

suction
1-1/2" straight pipe 8'
1-1/2" 90 degree ells seven total
1-1/2" 45 degree ells two total

supply
1-1/2" straight pipe 8'
1-1/2" 90 degree ells three total
1-1/2"X1"X1" wye one total
1" 90 degree ells eight total
1" 45 degree ells two total
1" flex pipe 10'
1/2" flex pipe 6'
1/2" 90 degree ells four total

6 jets have 0.25 orfice
2 jets have 0.35 orfice

lift from motor base to highest jet is approx. 42"
NOTE: I am counting each jet base as a 90 degree ell

 

is the 42" going downstairs? or where pump is originally? Need to know from where pump will be located.

 

The 42" takes into consideration that the pump will be mounted in the basement. That 42 means the base of the pump will be 42" lower than the height of the highest jet in the tub.

Not sure how to figure gallons that the tub holds but I have attached a sketch. My guess is approx. 80 gallons because I open both the hot and cold to fill the tub and when it's full the 40 Gallon gas water heater is just starting to run cold. Make sense?

Anyway I have attached a drawing of the shell.

 

I still can't wrapmy head around the 42" are you mounting this pump up near the ceiling under where the tub is? This is only 3.5 feet??? I am trying to be sure about measurements.

 

That is correct I built a pump platform near the ceiling in the basement. There will be less than a 4 foot head overall.

 

ok, I would go with a hayward sp1580 without the leaf trap. You might find it without it(cheaper) but if not, it unscrews. They're around 150.00

 

Would you be so kind as to tell me what the GPM requirements considering lift, jets, and piping of my application as well as the HP and GPM for the SP1580 pump?

 

I don't remember exactly now but the sp1580 pumps at 10' head which is min in chart around 70gpm so at a 3-4' head you should get around a 90gpm which should give you some good action in tub. You might even have to install a ball valve to throttle down a little.
Best I could come up with is the tub needs about 80gpm

 

Took your advice and ordered the SP1580 pump today, Should see it by Thurs or Friday of this coming week. I'll take a few pictures of the basement install and let you all know how it turns out. Keep your fingers crossed.

BTW: If you know anyone looking for a new Balboa pump let me know, I'll make them a heck of a deal.

 

Got the new Hayward sp1580 pump installed and it seems that we are now healed.

I installed a valve in the discharge and also a bypass loop with valve in case the pressure was too high. I needed neither as the jet action is great.

Thanks for all the advice and help guys, you are all life-savers!

 

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