bigger pump = more pressure?

[92rslt1]

Well my pdc 5 person spa pump has died and I am in the market for a new one. I am actually glad it died becuase it wasnt really as powerful as I think it should have been. It would not properly operate the mechanical jets unless I blocked two others off. Yes, the filter was clean and passages free of debris. It either was tired, under powered or the wet end is weak. The old motor was a 1.5 hp hayward with a hayward wet end.

I am buying a new motor and wet end.

My question is what wet end should I look for for more jet pressure? will going up to a 2hp help? does the 1.5 and 2 hp have a different wet end?
My spa pack supports a 1.5 or 2hp rating.
What I dont want to do it buy a pump thats going to do the same as a smaller pump but use more electric.

[Tman122]

The problem with up-sizing the pump is that it may not do any good depending on the engineering of your plumbing. As you spend less on value type tubs you have a tendency to end up with under engineered plumbing to save cost. A 2HP may help a little but be careful you don't blow your plumbing apart.

[Jacuzzi Jim]

  You are probably also limited to a 110v motor?   In which case you are stuck with a 1.5 or 2.0 HP pump.   As far as I know??   A 2hp would be a little better but not much..

[92rslt1]

Its a good sized tub, the plumbing is 2 inch OD reinforced hose to pvc then to the jets. I dont think it will blow apart pvc at any pressure i could throw at it. It was a good tub back when it was made... but its pretty old compared to new tubs.

Its a 220v tub.

[Jacuzzi Jim]

  Just make sure it's a 220v motor.  If so you could go with a 2.5hp, now depending on how many jets there are it could be harder on the system and as you build up back pressure (not enough jets for flow) with the pump running on high that's where you can start having issues. 

[Tman122]

Its a good sized tub, the plumbing is 2 inch OD reinforced hose to pvc then to the jets. I dont think it will blow apart pvc at any pressure i could throw at it. It was a good tub back when it was made... but its pretty old compared to new tubs.

Its a 220v tub.

PDC has never made anything but value tubs. They still do. I'm not saying their a bad tub just inexpensive. Blowing the PVC apart was just an analogy. Engineered plumbing has less corners, smoother street fittings, better designed manifolds and straight inputs for pumps. Several other things also contribute to jet pressure.

[Chas]

There is no way to be sure you will get more umph at the jets with a larger pump. Several people have mentioned "engineering," and I will back that up. I have added HP to spas at my customer's request many times. I try to tell them I doubt it will work, but they tell me they are 'engineers' or some other profession and they feel they know more than I. Fine - I'll take the job. But it never works - most companies (HotSpring very much included) know how to wring the most water flow out of the smallest tubing. In other words, they seldom put in piping which is larger than needed. That would cost more, and be a waste of money. yes, I HAVE seen some tubs which run 2" pipe all around, because in their case that makes the plumbing job go faster and easier, and that also equals lower cost. But in those cases, the jets themselves are usually also smallish, or may need to be resized or rejetted to take advantage of any extra flow. And then there is the suction side: most makers will not put in oversized suction fittings or plumbing, so you make put in your larger pump(s) and hear the thing cavitate and STILL not get what you are looking for.

If you read this and say, "I can fix any or all of those problems," then you are setting your course for quite a project. And if you have time and money for that, fine. But chances are you may spend close to the price of another tub, even if that other tub is a top brand used unit.

HTH

 

[TwinCitiesHotSpring]

Its a good sized tub, the plumbing is 2 inch OD reinforced hose to pvc then to the jets. I dont think it will blow apart pvc at any pressure i could throw at it. It was a good tub back when it was made... but its pretty old compared to new tubs.

Its a 220v tub.

PDC has never made anything but value tubs. They still do. I'm not saying their a bad tub just inexpensive. Blowing the PVC apart was just an analogy. Engineered plumbing has less corners, smoother street fittings, better designed manifolds and straight inputs for pumps. Several other things also contribute to jet pressure.

100% spot on post....I guarantee a PDC is full of 10 and 12 port manifolds (mickey mouse plumbing as I call it) so if the cost is more than minimal I wouldn't even spend the money on up-sizing because your performance will not increase much

[92rslt1]

Well thanks guys. I'm not gonna argue with logic. What you say makes sense. The 1.5 pump was 209 and the 2hp was 239 so I just ordered the 2 hp. I needed the pump any was so its only a small gamble. My hot tub was given to me free a few years back and has been a good unit so far so a few hundred bucks doesn't hurt my feelings too much.

[wmccall]

Having just gone from a medium quality tub to a higher quality tub I can definitely speak the aspect of quality plumbing/engineering.  My degree is in Electronic Engineering and I'll freely admit I don't know jack about plumbing. On my old tub it was clearly built with number of jets and horsepower rating in mind as selling points, not neccesarily for efficiency. I had a couple of jets and controls that had very little flow and others that could be used to cut steel.  My diverters were also cheap and failed a lot.   

My new tub gives strong jets with half the supposed horsepower and all the jets function the way they should.

[Tman122]

Well thanks guys. I'm not gonna argue with logic. What you say makes sense. The 1.5 pump was 209 and the 2hp was 239 so I just ordered the 2 hp. I needed the pump any was so its only a small gamble. My hot tub was given to me free a few years back and has been a good unit so far so a few hundred bucks doesn't hurt my feelings too much.

I would of done the same thing but I wouldn't expect a noticable difference.

[Seadoo951]

Just curious what the outcome was with the new pump?