Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 19 of 19

Thread: Pentair MasterTemp 400 cycles on and off in Spa mode

  1. Back To Top    #1

    Join Date
    Apr 2007
    Location
    Livermore, CA
    Posts
    32

    Pentair MasterTemp 400 cycles on and off in Spa mode

    Hey all,
    I have a Pentair MasterTemp 400, which is about 2 years old. Recently it started cycling off and on while attempting to heat my spa. It cycles every 2-3 minutes and runs for a minute or two at a time. I did run it for about 10 minutes while circulating my pool as well, and didn't detect it cycling at all, which makes me think it may be pressure related, but I'm not sure that to look at next.

    Cleaned my filter cartridge today, which helped flow, however it didn't fix the problem.

    Any suggestions???

    thanks!
    Darren
    ~20K gallon freeform w/attached spa
    Pentair 4x160 pump
    Pentair Mastertemp 400K BTU heater
    Intellitouch i7+3 controller
    Intellichlor IC40

  2. Back To Top    #2

    Join Date
    Apr 2007
    Location
    Livermore, CA
    Posts
    32

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    Found the manual for the heater, and tried adjusting the water pressure switch - no joy. Seems like the water pressure switch might need replacing. Next dry day I'll pull things further apart and jump across the WPS to see if it'll run for more than a few minutes. Anyone know if replacing that doohickey is expensive or a possible DIY item for a competent DIYer?

    thx
    Darren
    ~20K gallon freeform w/attached spa
    Pentair 4x160 pump
    Pentair Mastertemp 400K BTU heater
    Intellitouch i7+3 controller
    Intellichlor IC40

  3. Back To Top    #3
    spishex's Avatar
    Join Date
    Oct 2008
    Location
    Hillsborough, NC
    Posts
    1,375

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    Does your service light come on? If so, you'll need to take a look at the backside of your control and see which LED is lit. That will give us more of an idea.

  4. Back To Top    #4

    Join Date
    Apr 2007
    Location
    Livermore, CA
    Posts
    32

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    Ah-HAH! Took a look at the backside of the board, and the HLS light comes on. Also found out this doesn't start until the inlet temp gets up to ~69-70*, which explains why it didn't happen when I was running it on the whole pool (pool is about 54* right now).

    So, is replacing the HLS something I can do? Or can it be adjusted at all? Can I bypass it for a few minutes to test that it is truly the problem?
    Darren
    ~20K gallon freeform w/attached spa
    Pentair 4x160 pump
    Pentair Mastertemp 400K BTU heater
    Intellitouch i7+3 controller
    Intellichlor IC40

  5. Back To Top    #5

    Join Date
    Apr 2007
    Location
    Livermore, CA
    Posts
    32

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    Ok, did a little more reading and poking. Found the HLS and shorted it - heater stays on. Just to be safe, I drew some water off the heater drain which is right below the outlet and HLS - it temp'd at 104*, so the HLS is at least 30* off. Then I pulled the HLS to look for visible corrosion/damage/buildup of some sort -nada.

    Anyone think it's a bad idea for an ign'ant sap like me to order a new one from poolcenter or somewhere and just swap it out? $30 for a new switch is a lot cheaper than the $65 warranty service call.
    Darren
    ~20K gallon freeform w/attached spa
    Pentair 4x160 pump
    Pentair Mastertemp 400K BTU heater
    Intellitouch i7+3 controller
    Intellichlor IC40

  6. Back To Top    #6

    In the Industry
    budster's Avatar
    Join Date
    Dec 2008
    Location
    Savannah Historic District
    Posts
    272

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    Understanding that the HLS is one feature in the "safety circuit" for a heater, IF you can replace it properly, I see no reason why not. It's pretty easy to do.
    http://www.swimmingpool.com/

    "Leave the gun...take the cannolis"

  7. Back To Top    #7
    spishex's Avatar
    Join Date
    Oct 2008
    Location
    Hillsborough, NC
    Posts
    1,375

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    Your heater has a two year warranty, and they've only been making the mastertemp for a couple of years now. Any chance you're still covered?

  8. Back To Top    #8

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    I have the same issue, but not sure which switch is which. On the attached diagram, from what I've read, the HLS is either 5, 6, or 7. Was it easy to replace?
    Attached Images Attached Images

  9. Back To Top    #9

    Join Date
    May 2009
    Location
    So Cal
    Posts
    44

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    Hello all,
    I have a pentair master temp 400 heater that is acting the same as in this thread. I checked behind the panel and the light that was on was; LED5, U11. Does anyone know what that indicator would mean. Thanks
    15 X 28, 12,000 Gallon, (IG) Freeform Dark Gray Plaster/Gunite with attached 10 X 7 Spa raised 18", 7 Jet with Spillover and Art Rock Waterfall/Grotto, Pentair Intelliflo VS-3050 for Pool, 2 HP Whisperflo for Waterfall/Grotto, Pentair Clean & Clear Cartridge 320, Pentair 400K BTU Matstertemp, Pentair EasyTouch 4P, Pentair Suction Side PoolShark Cleaner, Stenner pump, autofill system, Plumbed for future Solar, TF-Testkit.

  10. Back To Top    #10

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    Check the thermostat, its very easy to replace. Its located near the inlet/outlet ports. Take a screwdriver and use the shaft to unscrew the retaining cap and it pops out. I was getting similar issues with it shutting off and found out my thermostat was corroded. It started with the HLS error and then switched to another error code (can't remember which one). Ordered new one on Amazon Prime and was good to go in 48hrs.
    IGP 8500gal, Jandy Aqualink RS with IAqualink, Jandy Watercolors LED, Pentair Clean&Clear filter, Pentair Mastertemp heater, Pentair 1.5hp Whisperflo pump, A&A in-floor filtration (garbage!).

  11. Back To Top    #11

    In the Industry
    Pool Clown's Avatar
    Join Date
    Sep 2008
    Location
    Silicon Valley, CA
    Posts
    1,393

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    jpcdmd is correct. If the heater heats to about 70-80 degrees then starts to cycle, the problem is most likely the thermostatic by-pass. When it does not operate correctly, it causes higher than normal temps in the header and the HLS will open.
    Factory Warranty Station for:
    Jandy, Pentair, Sta-Rite, Raypak, Polaris,
    and Paramount pool cleaning systems.

  12. Back To Top    #12

    Join Date
    Apr 2016
    Location
    Tulsa, OK
    Posts
    9

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    Is this the temperature sensor that is wired directly back to the IntelliTouch?

    Also, While removing this sensor, a portion of the plastic (about 1inch of the outer plastic) broke off and fell back into the PVC pipe. This is in the inlet pipe to the heater. I don't see that there is any filter/screen within the heater to catch this - what would happen if I still run the system with the new sensor? Otherwise I may have to replumb that section to try to find it (if I can). Because once the sensor was removed, the open system then refluxed the water so that piece may have moved retrograde and I'm not sure where it would have truly ended up. Thanks in advance for the help!



    Quote Originally Posted by Pool Clown View Post
    jpcdmd is correct. If the heater heats to about 70-80 degrees then starts to cycle, the problem is most likely the thermostatic by-pass. When it does not operate correctly, it causes higher than normal temps in the header and the HLS will open.

  13. Back To Top    #13

    In the Industry
    Pool Clown's Avatar
    Join Date
    Sep 2008
    Location
    Silicon Valley, CA
    Posts
    1,393

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    No. What broke for you was the water temp sensor. You should probably fish that out. It may pass, it may not. BTW, you may want to consider relocating that temp sensor. It should go between the filter pump and the filter.
    Factory Warranty Station for:
    Jandy, Pentair, Sta-Rite, Raypak, Polaris,
    and Paramount pool cleaning systems.

  14. Back To Top    #14

    Join Date
    Apr 2016
    Location
    Tulsa, OK
    Posts
    9

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    Thank you Pool Clown! Then what part number is the thermostatic bypass that I need to replace (sorry to be such a novice) as mine seems to be doing the exact same cycling as mentioned above. Thank you for the help!

  15. Back To Top    #15

    In the Industry
    Pool Clown's Avatar
    Join Date
    Sep 2008
    Location
    Silicon Valley, CA
    Posts
    1,393

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    You can get #16 by itself, or you can get the kit #15.

    Click on the exploded view for a larger view.
    They call it a regulator, so you wont confuse it, when ordering, with the by-pass #8

    Sta rite Max E Therm SR Heater Parts (Water System)
    Factory Warranty Station for:
    Jandy, Pentair, Sta-Rite, Raypak, Polaris,
    and Paramount pool cleaning systems.

  16. Back To Top    #16

    Join Date
    Apr 2016
    Location
    Tulsa, OK
    Posts
    9

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    Ordered! Thank you for the help! Now to try to find that stupid little broken plastic piece... Ugh.

  17. Back To Top    #17

    Join Date
    Apr 2016
    Location
    Tulsa, OK
    Posts
    9

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    Just to clarify, I can pull this out and replace #16 without having to take off the manifold, correct?

  18. Back To Top    #18

    In the Industry
    Pool Clown's Avatar
    Join Date
    Sep 2008
    Location
    Silicon Valley, CA
    Posts
    1,393

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    Yes.
    Factory Warranty Station for:
    Jandy, Pentair, Sta-Rite, Raypak, Polaris,
    and Paramount pool cleaning systems.

  19. Back To Top    #19

    Join Date
    Apr 2016
    Location
    Tulsa, OK
    Posts
    9

    Re: Pentair MasterTemp 400 cycles on and off in Spa mode

    You rock! Thanks for your help Pool Clown!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •