Help on pump prime of Pentair intelliflo variable speed pump

[yangcha1]

Today I replaced my old Pentair Whisperflo pump with Pentair intelliflo variable speed pump myself. Everything is fine except the pump cannot prime the water. Is it because of suction side air leaks or wrong setup? I just used the factory default setting now. My old pump primes no problem.

Thanks a lot!

--Yang

 

[Texas Splash]

This may sound basic or silly, but have you already tried standing over the new pump basket with lid off and tried to fill with a garden hose or 5-gal bucket to keep it flooded as it tries to initially prime?

 

[yangcha1]

Thanks for your reply.

Yes, I did fill water to the pump basket. The old pump can prime within half a minute or even faster.

This may sound basic or silly, but have you already tried standing over the new pump basket with lid off and tried to fill with a garden hose or 5-gal bucket to keep it flooded as it tries to initially prime?

 

[Jimrahbe]

Yang,

So what happens when you turn the pump on? Does it increase in speed as it tries to prime? Does it shut off before priming or are you turning it off? Please describe the sequence and timing of what happens.

Are you sure the big O-Ring is under lid? I've actually installed the lid without the O-Ring before and only noticed when I saw it on the ground. Duh!!

Jim R.

 

[yangcha1]

Yes, it increases in speed as it tries to prime. After a few minutes without priming, I shut it off to avoid the damage to the pump. My old pump is Pentair whisperflo which primes in half a minute or even shorter.

Yes, I always put the O-ring and always lubricate it.

Thanks,

--Yang

Yang,

So what happens when you turn the pump on? Does it increase in speed as it tries to prime? Does it shut off before priming or are you turning it off? Please describe the sequence and timing of what happens.

Are you sure the big O-Ring is under lid? I've actually installed the lid without the O-Ring before and only noticed when I saw it on the ground. Duh!!

Jim R.

 

[Divin Dave]

While its trying to prime, look in the skimmer and make sure the pump isnt creating a vortex in there.

The intelliflo has an protection ciricuit on it. It will go to "fault" with red light when it is in danger. Leave the pump running to let it prime. Open the air bleed valve on the filter occasionally to release the air out of the system. It will prime.

 

[yangcha1]

Thanks, that is encouraging. Usually how long does it take to prime for Intelliflo? My old pump Whisperflo primes within half a minute.

I always open the air bleed valve on the filter to let the air out when priming. Is that right way to do?

Thanks.

While its trying to prime, look in the skimmer and make sure the pump isnt creating a vortex in there.

The intelliflo has an protection ciricuit on it. It will go to "fault" with red light when it is in danger. Leave the pump running to let it prime. Open the air bleed valve on the filter occasionally to release the air out of the system. It will prime.

 

[Jimrahbe]

Yang,

Did you double check the position of any input valves controlling the input from the skimmer(s) and main drain?

Jim R.

 

[yangcha1]

Yes. since I was replacing the old pump with new one, I did not touch the valves.

Yang,

Did you double check the position of any input valves controlling the input from the skimmer(s) and main drain?

Jim R.

- - - Updated - - -

Davin,

I suspect the air leak comes from the male union fitting to the pump house. I used teflon tape and hand tightened it. It is 2 inches PVC union. I saw someone was using pipe dope. But I was worry it is permanent to the PVC.

Thanks.

While its trying to prime, look in the skimmer and make sure the pump isnt creating a vortex in there.

The intelliflo has an protection ciricuit on it. It will go to "fault" with red light when it is in danger. Leave the pump running to let it prime. Open the air bleed valve on the filter occasionally to release the air out of the system. It will prime.

 

[yangcha1]

Thank you all for the tips and suggestions. I just bought a can of Oatey Great White pipe dope and now the pump primes pretty fast.

The only issue is the PVC fitting to the outlet of the pump. The water is seeping from the pump outlet very very slowly. Is there anyway to fix it? I hand tightened the PVC fitting and I don't want to crack it.

I put two layers of teflon tape then applied atey Great White pipe dope. Do I need to put more teflon tape or less?

Thanks,

--Yang

Yes. since I was replacing the old pump with new one, I did not touch the valves.




- - - Updated - - -

Davin,

I suspect the air leak comes from the male union fitting to the pump house. I used teflon tape and hand tightened it. It is 2 inches PVC union. I saw someone was using pipe dope. But I was worry it is permanent to the PVC.

Thanks.

 

[Agent99]

I wouldn't mix pipe dope AND teflon tape...that can crack things. Stick with pipe dope only and you can tighten it pretty good. You can go a full turn or two beyond hand-tight with a pipe wrench no problem.

I did this on my Pentair IntelliFlo and no leaks at all and mine primes very quickly.

What is the size and length of straight pipe from the valve to your Pentair? You want that to be 5x the pipe size if possible so a 2" line would like a straight piece of 10" pipe entering the pump.

My pipe is 2" all-around but I went 2.5" and 12" of length straight into the pump and mine primes in under 10 seconds.

 

[yangcha1]

Chris, thank you for your suggestion.

From this forum, I get at least three options:

1) As Chris suggested, stick with teflon based pipe dope only.
2) Stick with teflon tape only
3) Mix pipe dope AND teflon tape.

So which one is the best? Is there any opinion from the industry?

By the way, I am curious why not the pump maker designed the pump outlets as the male adaptor of the union like this:


then at least half of the leaks reported in this forum will be gone. And it is much easier to install.

--Yang

I wouldn't mix pipe dope AND teflon tape...that can crack things. Stick with pipe dope only and you can tighten it pretty good. You can go a full turn or two beyond hand-tight with a pipe wrench no problem.

I did this on my Pentair IntelliFlo and no leaks at all and mine primes very quickly.

What is the size and length of straight pipe from the valve to your Pentair? You want that to be 5x the pipe size if possible so a 2" line would like a straight piece of 10" pipe entering the pump.

My pipe is 2" all-around but I went 2.5" and 12" of length straight into the pump and mine primes in under 10 seconds.

 

[Agent99]

Yang,

All I can tell you from what I've read and experienced is that mixing pipe dope and teflon tape can bind things too much in a plastic threaded joint and failures, leaks, and cracks can occur. It is just too much stuff in the threads...the plastic threads. Metal is a different story and much stronger. For me, I now go with all pipe joint compound and no longer use teflon tape as I've experienced too many failures and leaks with teflon tape. Talk to most professional plumbers and they all prefer to use some kind of a pipe dope/compound. This compound is my favorite: Thread Sealing compounds I use it everywhere and it simply works.

As to the pipe for the pump, it is kind of like selling you a new stove/oven: they never come with a cord because there are simply too many ways/options and plug style one might need or use to get electricity to the appliance!

I should post a pic of the pipe I have heading into my pump. From my Jandy valve, I have a 2.5" female adapter glued to the OUTSIDE of the valve (this is the valve than can take 2" inside or 2.5" outside on its fittings), a 2.5" pvc pipe nipple 12" long screwed into that, then another 2.5" female adapter screwed into the other end of the nipple. Glued into the female adapter is a bushing taking the 2.5" down to 2" threaded. And yep, another 2" pvc pipe nipple is then screwed into the bushing and subsequently screwed into the pump. This crazy thing was at the suggestion of an old-timer at Pentair as he told me that he personally guaranteed the pump would prime in under 10 s if I did all this. He was right! This set-up simply allows a very large volume of water into the pump right away and that is key. That 2.5" pipe's area is over 50% larger than the 2" pipe's area. That makes a big difference.

 

[yangcha1]

Chris,

Thank you for your information. Very informative. From this forum, it seems it is a consensus that pipe dope is more popular than teflon tape. Teflon tape seems to be a old school technique.

For the inlet and outlet of the pump, if they are female type, then we need to put unions to them. From my limited experience, the union joint and the PVC threading to the pump outlet or inlet are the two weakest links. But if the pump has male adaptor of the union, then there is only one weakest link, reducing the chance of failure by half.

Thanks,

--Yang

Yang,

All I can tell you from what I've read and experienced is that mixing pipe dope and teflon tape can bind things too much in a plastic threaded joint and failures, leaks, and cracks can occur. It is just too much stuff in the threads...the plastic threads. Metal is a different story and much stronger. For me, I now go with all pipe joint compound and no longer use teflon tape as I've experienced too many failures and leaks with teflon tape. Talk to most professional plumbers and they all prefer to use some kind of a pipe dope/compound. This compound is my favorite: Thread Sealing compounds I use it everywhere and it simply works.

As to the pipe for the pump, it is kind of like selling you a new stove/oven: they never come with a cord because there are simply too many ways/options and plug style one might need or use to get electricity to the appliance!

I should post a pic of the pipe I have heading into my pump. From my Jandy valve, I have a 2.5" female adapter glued to the OUTSIDE of the valve (this is the valve than can take 2" inside or 2.5" outside on its fittings), a 2.5" pvc pipe nipple 12" long screwed into that, then another 2.5" female adapter screwed into the other end of the nipple. Glued into the female adapter is a bushing taking the 2.5" down to 2" threaded. And yep, another 2" pvc pipe nipple is then screwed into the bushing and subsequently screwed into the pump. This crazy thing was at the suggestion of an old-timer at Pentair as he told me that he personally guaranteed the pump would prime in under 10 s if I did all this. He was right! This set-up simply allows a very large volume of water into the pump right away and that is key. That 2.5" pipe's area is over 50% larger than the 2" pipe's area. That makes a big difference.

 

[Agent99]

I have no unions on mine...that is just another point where things can leak.

 

[yangcha1]

No union? What if there is leak on the threading to the pump housing? Then you need to cut and redo? Could you kindly post your pipe connections?

Thanks,

--Yang

I have no unions on mine...that is just another point where things can leak.

 

[Agent99]

As I stare at my pipe, I've just realized that I would have to either cut the pipe or spin my pump to disconnect it!!! LOL!

Thinking back when I plumbed this, I understand what I now did.

Thankfully, and because I used that pipe compound I posted earlier, I had no leaks but I think I'll be picking up some unions now for the future just in case.

The output port on the pump does go to a union but that union is part of the filter

 

[jmastron]

I installed my IntelliFlo with unions like this:

Pump Union for Pentair IntelliFlo Threaded Union 2" MPT x 2" Slip (2 Pack)

I got mine from a local pool store, a generic brand. They have an O-ring on the fitting that screws into the pump (in addition to in the union itself) as the primary seal; I didn't use any tape or dope on the threads and have no leaks. Does your union have an O-ring there? If so, using tape or dope may be preventing you from screwing it in tight enough to compress the O-ring.

On the old pump, I had used teflon tape on a threaded fitting into the pump and it leaked a lot (and because I didn't have a union, it was not fixable without redoing the whole section of piping), so using these unions was well worth the cost.

 

[yangcha1]

Thanks,

There is no leaking from the union itself because of the O-ring. The leaking comes from the threading to the pump housing.

I installed my IntelliFlo with unions like this:

Pump Union for Pentair IntelliFlo Threaded Union 2" MPT x 2" Slip (2 Pack)

I got mine from a local pool store, a generic brand. They have an O-ring on the fitting that screws into the pump (in addition to in the union itself) as the primary seal; I didn't use any tape or dope on the threads and have no leaks. Does your union have an O-ring there? If so, using tape or dope may be preventing you from screwing it in tight enough to compress the O-ring.

On the old pump, I had used teflon tape on a threaded fitting into the pump and it leaked a lot (and because I didn't have a union, it was not fixable without redoing the whole section of piping), so using these unions was well worth the cost.

 

[jmastron]

Thanks,

There is no leaking from the union itself because of the O-ring. The leaking comes from the threading to the pump housing.

Right -- the unions I used have an additional O-ring outside the union against the pump housing, so that threading doesn't have to seal, it just pulls the O-ring tight. I'm sure it's possible to seal threaded fittings with dope or tape on the threads themselves, I just have never done so successfully (the twice I tried on the old pump). I gather that larger threaded fittings are harder to seal that way (vs say a 3/4" metal pipe thread), and these unions eliminate the need to do so.

It might help to post some pictures of your unions and connections at the pump, might give people some more ideas.