No pump!

Sep 14, 2013
10
Tucson, AZ
Hello, I have a Grecian In-ground octagonal Jacuzzi that was installed around 1989 by the original owner of my home. The Jacuzzi worked well for the first few years that we lived here, then the copper heat exchanger on the heater began leaking. The Jacuzzi was left sitting for a couple of years until about 3 years ago when I got a used heater. I installed the heater and fired it up to find the mitra cartridge filter housing had rotted away and was spraying water everywhere. Again the Jacuzzi sat until this year. I decided to get it going for my wife for Christmas and ordered a new cartridge filter system. I got it piped in, tried to turn on the pump, but the pump just hummed. I pulled the pump apart and found the impeller was frozen to the diffuser and the seal was shot. I replaced the impeller, diffuser, all O-rings, and pump seal. After replacing these parts, the pump wouldn't prime. I dug up the first few feet of pipe, so I could replace the threaded fitting that goes into the suction side of the pump, figuring that I may have wiggled the fitting while working on the pump. I pulled the threaded fitting off of the pump and decided to run a 2" line from the pump directly into my swimming pool, to see if it would pump, but no. I am ready to order a new pump, but was wondering if I am missing something? Also, the spa has a Pac Fab 2 HP pump. It has 2" lines and the Jacuzzi is about 40' from the pump. Is 2HP the proper size? My 20,000 gallon swimming pool has a 3/4 hp pump, so it seems extreme for a small Jacuzzi to have 2 HP, unless it is for the jets? Thanks much for any advice.
Pete
 
The larger pump is needed for the jets.

But if the pump is running, has water in the pump basket and it still does not prime, then there is probably an air leak somewhere and usually in the pump lid gasket or drain plugs. Make sure all those gaskets are in good condition and use some pool lube on them to help seal them.
 
Thanks for responding mas985. The pot is full of water and I have replaced and lubed all O rings with Magic Lube, including the 2 drain plug o rings. The pump lid O ring sits above the level of the housing and the lid sits nicely on the O ring and compresses it as I tighten it. The only fittings external to the pump are the 2" male pvc adaptor and 20' of 2" pvc that elbows directly down into my pool (to test the pump).I'm by no means and expert, but I don't see how there is a leak, unless the housing is cracked somewhere. It is almost 30years old. When I run the pump, I can see water slowly running into the strainer for the first 30 seconds or so (through the clear lid), but it never pull any more than that. When I remove the lid right after running the pump, there is a little vacuum in the pot. I appreciate your response. Do you have any other suggestions as to where to look?
 
A crack in the pump housing is certainly possible so I would look for that. Also, did you make sure the impeller was clean and free from debris. That can also prevent priming.


When I remove the lid right after running the pump, there is a little vacuum in the pot.
There would not be any vacuum after shutting off the pump. Any pressure differential is removed through the suction and return lines after the pump turns off.
 
Ya. Impeller is brand new. When I remove the lid right after shutting off the pump, there is definately negative pressure that is released as I open it. Could this indicate an issue?
There might be a little negative pressure if the pump is well above water level.

The pump is running and impeller spinning, correct?

If it just isn't priming, then it is either an air leak or perhaps a plugged suction line. You can try flushing the suction line backwards from the pump to the skimmer and see if anything comes out.
 
I ran a line directly from the pump into my swimming pool to eliminate the possibility of a plug. I pulled the pump apart again today and re-lubed all the o rings and looked at the pot, lid etc for cracks. Nothing obvious. I tried to replace the new OEM O ring between the pot and the pump with a fatter o ring. It looked like it was barely making contact with the mating surface, but nothing. Yes the pump is running and impeller is spinning. Both the impeller and diffuser are new. I double checked the impeller and diffuser part numbers to make sure that I purchased the correct parts and all were correct. I'm stumped.
 
IT"S PUMPING WATER!!!! I realize this is not as exciting to everyone else, but man am I happy. Thanks to Mark and Swampwoman for trying to help. Turns out it was a boneheaded mistake by me. Imagine that. When I replaced the diffuser, it has a leg that is supposed to recess into a hole in the diffuser spacer, but I failed to get it into the hole so the diffuser had about a 3/16" gap between itself and the spacer at the top. It also had a bit of gap between the impeller and the diffuser. Mark, one of the videos that you posted in "Self Priming Pump Basics pt 2" led me to find this. The guy in the vid talks about "face clearance" and I remembered that there seemed to be excessive clearance between the neck end of the impeller and the end of the diffuser. I also saw a vid on the disassembly of Challenger and noticed much less gap on the model pump in the vid. Thanks again! Happy New Year
 

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