Shared Knowledge


How to: Repair a Laing 909 Series Circulator Pump


12 September 2006

Updated: 21 August 2010

Updated: 21 June 2011

Updated: 4 January 2014




Summary: the Liang Model SM-909-NTW-18 3/4 is no longer available from Laing. It has been replaced by another Laing pump. Pump repair kits for the old SM-909-NT-18 3/4 may be available some where on the Internet but a limited search I performed yielded nothing specifically for the NTW-18 3/4 model. An eBay search periodically may yield a repair kit for the SM-909-NTW-18 3/4. At a minimum, take pump apart and ensure it is not working just because of hard water deposits.







I have a 12 year old hot tub, which uses a Laing Model SM-909-NTW-18 3\4 circulator pump. The circulator pump is what moves water through the heater assembly on a 7-day a week, 24 hour a day, basis


5 years ago, my circulator pump failed and I went to a hot tub dealer and bought a new pump to the tune of $249.


A month ago, checking the hot tub, as I routinely do, I found the circulator pump not working again! Not another $249! So, this time I did some research on the Internet and found that repair kits are sold for Laing 909 series circulator pumps (not told to me at dealer when I bought a complete new pump, of course). The repair kit is not cheap at $80 but not $249 either.


Would the pump repair kit actually fix my pump? I had no way of knowing. I did notice that when I took the pump out of the hot tub and would shake it, I could hear the actual pump end of the circulator rattle as if something was loose. Not remembering how the pump sounded when brand new, I really did not know if the repair kit would fix this problem or not but was willing to take a chance.


Turns out when I got the repair kit, the new piece has a spring of some kind, I can not see, which keeps the actual impellor of the pump pushed away from the motor gasket and towards the pump housing. I am not explaining it correctly but when I reassembled the pump using the repair kit, no more rattling sound, so I know the new pieces are different than the old and thus fairly sure I have solved the problem although it is too late in the year to fill the tub again to actually test the pump.




To repair the pump:


To repair the Laing 909 pump I have, I removed all bolts (4) holding the pump housing from the actual motor. The image below shows the pump housing separated from the motor body. Once you remove the bolts, the pump housing comes right off the motor body.




Below is what you get in a Laing series 909 pump repair kit. Although you receive 2 rubber gaskets, you will only need one. As it is a kit, they include gaskets to fit slightly different motor bodies.




The image below shows the actual impellor of the pump.



The image below show the pump housing with the actual pump removed. Once you separate the motor from the pump housing, all you do is lift up on the metal ball and pull the assembly out of the pump housing.




You now take the pump repair kit and install it on the motor body. The rubber gasket will fit right down into a groove in the motor body. You will note that I have the motor held vertically during this process.




Now put the pump housing on the motor body while the motor body is vertical and begin to reinsert the bolts, which hold the pump housing to the motor body.



Note that when you reassembly the pump housing to the motor body, make sure you use the holes in the pump housing, which have nut recesses. The image below details nut recesses.



As with any parts assembly, get all (4) bolts installed at about the same torque and then go around again and make sure all are tight.


Of course, it is possible that the wiring in the motor has gone bad for some reason but in my case, I am fairly sure that the repair kit is going to take care of the job. Why the pump portion went bad on me, I do not know. As I said, it is obvious that some sort of spring broke for some reason, which allowed the impellor to get caught on the side of the pump housing.


Update 21 August 2010:


Installed pump and it worked fine but then because of house renovation, sold hot tub, thus do not know how repair kit has held up over they past several years.


Get emails now and again about my Laing repair because repair kit specifically says "not for hot tub use." Well, repair kit is sold for Laing pump that was installed in my hot tub so either hot tub manufacturer used Laing when they shouldn't have or Laing just covering their butts somehow with hot tub warning.



Update 4 January 2014:


Recent email from Phil Brown says he took pump out of system, opened it up and found hard water deposits were keeping the pump from turning properly. He cleaned out deposits and pump working again!!




Ron - Shared Knowledge Home