Replaced Pentair pump. First install attempt, used teflon tape on threads, massive leak on discharge. Had to rebuild a bunch of piping to try again. Blow dried the fittings and used Rectorseal 5 (without any teflon tape), spread it heavy on male and female threads, tightened down as hard as I could by hand, was concerned about cracking the housing so I did not use a wrench, lots of sealant oozing out so it's hard to tell but it looks like it's got to be almost bottomed out. Started up and I have a very minor weeping through the joint. I have one more shot to get it to seal prior to having to do a major piping replacement due to running out of places to cut. First, I assume that I should not be so concerned about cracking the casing or messing up the threads, should I go until hand tight and then crank it down with a wrench until bottomed out? What should I use for sealant? Watched a video where a pool guy uses teflon tape with 3 rings of silicone on the threads (both under and over the tape), this seemed a little extreme but this is a real problem. I don't care one bit about being able to take it apart as long as it's not leaking, the old one was in place for 17 years. Any guidance would be appreciated. Thanks.
How to seal Pentair pump discharge
- Thread starter Kevin Gobeil
- Start date
- Jun 24, 2021
- 16,376
- Pool Size
- 29000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-60 Plus
You should use pentair pump unions.
What is the pump model number.
Post some pictures of the pump/connections and pad area.
What is the pump model number.
Post some pictures of the pump/connections and pad area.
The replacement housing kit is model number 357149, for Intelliflo and Whisperflo pumps, with 2" female threads.
The first pic is the new pump installed, the second pic is a closeup of the discharge, the third pic is the original pump which did not have a union or a male adapter, they actually threaded the 2" PVC and installed directly into the pump with a bead of silicone on the outside (I've heard when this is done they typically glue it in also, not sure because I did not try to unscrew it).
The first pic is the new pump installed, the second pic is a closeup of the discharge, the third pic is the original pump which did not have a union or a male adapter, they actually threaded the 2" PVC and installed directly into the pump with a bead of silicone on the outside (I've heard when this is done they typically glue it in also, not sure because I did not try to unscrew it).
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Get some high-temp pump unions that seal with and O ring and the fitting threaded completely against the pump housing and O ring. I also use 3 wraps of T tape on them as a precaution. I've been using the Teflon tape with silicone for over thirty years and I have zero leaks (I really don't like call backs for a simple leak). They are the only fittings that are designed to be threaded completely into a female port as the thread are not tapered as a pipe thread.
If you tightened the male pipe adapter completely into the housing, it is ruined as there should always be between 3 and 5 threads showing when it is properly tightened. Its possible that, after 17 years, the pump housing is damaged from the fittings being in too far.
- Jun 24, 2021
- 16,376
- Pool Size
- 29000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-60 Plus
Thanks a lot for the information, I'll have the high temp pump unions today. I wish I had known this a week ago but better late than never.
Installed the coupling on the discharge side, nice fitting, stopped the leak. My next issue is the fact that the pump doesn't seem to fully prime, even at full speed it doesn't completely fill the suction side of the pump up to the cover, the level is somewhere between the top of the strainer basket and cover, and at lower speeds it actually loses prime. Of course I looked for suction side leaks, I do not have a high temp union on the suction side, just a male adapter, but I have the gap between the pump inlet flange and the top of the top of the adapter (remaining threads area) sealed with silicone RTV, this is how the original pump was set up, I just had to replace the RTV once in a while when it degraded. To install the high temp union on the suction side I would have to rebuild the suction side and replace 3 3-way valves and potentially 2 vacuum breakers. Then I replaced the stem and body O-rings on all the Pentair 3-way valves on the inlet side, I re-lubed O-ring and over-tightened the strainer cover. I checked the drain plugs for tightness (though I will take them off just to verify the O-rings are in place and lubed). I'm starting to wonder about things outside of a suction issue. As far as configuration, I installed a new Pentair impeller 073129 into a new pump housing 357149, with a new diffuser 072927, with new variable speed motor ECM16SQU (1.65 HP, square flange), this seemed to be a compatible configuration. Any thoughts where to look?
sktn77a
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