Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 6 of 6

Thread: Hot Tub heating and cycle time question

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. Back To Top    #1

    Join Date
    Jul 2018
    Location
    Davenport, FL
    Posts
    32

    Hot Tub heating and cycle time question

    Hi all, new to hot tubs, one came with the house we bought and just now starting to clean and power it up. I had a air lock that I was able to fix, but my next quandary is it doesnít appear that there is a heater installed. It this typical? I can move water, jets work and even the control panel has a temp setting, but looking at the pump and control board I see nothing that looks like a heater.

    Balboa VL200 is the control panel
    Mach - 7 is the control board.

    Second, when itís plugged in the jets start up right away, the light under the jet button lights up and if I try to push the button, I can kinda feel a click but Iím not 100%sure the button is actually working. Will a stuck button just keep the jets on forever? Iím guessing I could get a new button pad. Is there a way to test? I suppose I could disconnect the key pad from the control board and then power up to see what happens.

    Thanks for any pointers.
    ~Pool Specs~
    In-Ground 10,000 Gallons, Liquid Chlorine | Pump: Century 1.1HP HST110 | Filter: Hayward Cartridge CX900RE | Heater: Solar Roof Panels
    Cleaner: Dolphin DX4 (AKA "The Kraken")
    Test Kit: K-2006

  2. Back To Top    #2
    Mod Squad Jimrahbe's Avatar
    Join Date
    Jul 2014
    Location
    Bedford, TX
    Posts
    9,830

    Re: Hot Tub or maybe itís a Spa questions

    m,

    I assume this is a standalone, fiberglass spa...

    If so, it would be hard to believe it does not have a heater.

    What is powering the tub?? Some tubs can be powered by 120 volts or 220 volts. When running on 120, the Jets and heater can never work at the same time. If the jets are always on, then the heater will never engage.

    Tell us more and show us a couple of pics of the "guts" under the maintenance doors..

    Thanks,

    Jim R.
    Finished in 2015 - 17K Gal, IG, 20' x 25' Almost Rectangular Pool, Pebble finish, three rockport water falls. Pentair Equipment: EasyTouch 4, IC40 SWG, 3 HP VS Pump, CCP520 Cartridge Filter.
    TF100 with SpeedStir and SampleSizer, ColorQ Pro 7, Dolphin Premier Robot Cleaner, added Screen Logic 2, added small 3 person Caldera Spa.

  3. Back To Top    #3

    Join Date
    Jul 2018
    Location
    Davenport, FL
    Posts
    32

    Re: Hot Tub or maybe itís a Spa questions

    ~Pool Specs~
    In-Ground 10,000 Gallons, Liquid Chlorine | Pump: Century 1.1HP HST110 | Filter: Hayward Cartridge CX900RE | Heater: Solar Roof Panels
    Cleaner: Dolphin DX4 (AKA "The Kraken")
    Test Kit: K-2006

  4. Back To Top    #4
    Oly's Avatar
    Join Date
    Jun 2017
    Location
    Fresno, CA
    Posts
    439

    Re: Hot Tub or maybe itís a Spa questions

    Some units are designed with friction flow heating systems. As I understand it pumps water through a device which generates friction and that heats the water. I find it hard to believe myself and am not sold on the concept but admit I have no experience using or inspecting a unit with this design. Search spa friction heater for more details.
    27,000 gallons of central CA well water housed in a fiberglass coated concrete/plaster pool, dug into the most productive top soil on earth and surrounded by an urban forest.
    Cleaned with a Pentair 48 sq ft DE filter and a Dolphin Discovery (S200) robot. 250 gal Hot Springs Solana RX stand alone spa. Taylor K-2006. My first thread... New Old House, New Old Pool....

  5. Back To Top    #5

    Join Date
    Oct 2017
    Location
    Roscoe, IL
    Posts
    219

    Re: Hot Tub or maybe itís a Spa questions

    What are those two pairs of white and black wires running off to? What does the board say by the plug? (Can't read it due to the picture angle)


    Quote Originally Posted by Oly View Post
    Some units are designed with friction flow heating systems. As I understand it pumps water through a device which generates friction and that heats the water. I find it hard to believe myself and am not sold on the concept but admit I have no experience using or inspecting a unit with this design. Search spa friction heater for more details.
    Any energy that goes into any pump has to come out. It comes out in two ways. Inefficiency of the motor makes the motor hot, which is some of the energy you supply the pump. The rest of the energy goes to actually moving the water. All this water moved eventually stops moving due to friction, this friction generating the heat. Whatever energy isn't lost due to motor inefficiency therefore heats the water. You won't notice this on a pool, as 1000-1500 watts of heat is nothing. On a well insulated spa on the other hand, it can be noticed.

    At work the equipment we use needs closed loop cooling. We've got some fair sized pumps for the loops, probably a few horsepower at least (high pressure, low flow compared to pool pumps. Typically we run them at ~120 psi output at 10-15 GPM). These push water through a heat exchanger to cool it, then through the equipment to remove heat, and back to the heat exchanger. If you run only the pumps (no equipment heat load) and don't have cooling water to the heat exchanger, the loops will get pretty toasty after a half hour or so, due to the friction heating of the water!

    All that said, I was under the impression spas that use friction heating are the cheapest of the cheapest spas, and they "cool" the motor with spa water so that the motor waste heat isn't wasted but instead goes into heating the spa water along with the friction heat. That's obviously not the case there, but that's still not saying it still couldn't be friction heated.
    Hot tub: Indoor Intex 28409E "Six Person" inflatable. 290 gallons. Taylor K-2006 test kit with Taylor 9265 Speedstir and TFT CYA test. Using dichlor/bleach/borax/muriatic acid.

  6. Back To Top    #6

    Join Date
    Jul 2018
    Location
    Davenport, FL
    Posts
    32

    Re: Hot Tub or maybe itís a Spa questions

    I think it could be a "Friction Heater", a quick Google search pulls up a device that looks almost exactly like the red piece that is on the output of the pump...which is leaking a bit so off to Lowes to get a pipe wrench. Can't turn it by hand, but it looks like it has a few more threads to go.

    The White/Black is the lighting, it metered to 13.5VAC.

    The temperature is rising, its gone up 3 degrees in the past 10min. So I think this whole friction thing is the case. I know nothing about the tub other than me digging into it, looking up part numbers or asking about it here. Its very likely it a "Cheap Tub", the previous home owners didn't leave any documentation.


    My new concern is the jets like to run forever. If I plug it in, and then immediately set the temp to below where it is now, they will cycle off. If I raise the set temp they will go on and stay on, even if I lower the set temp again. I'm guessing there is some kind of duty cycle thing it has to complete, the user manual for the VL200 doesn't seem to match up fully to what I have.
    ~Pool Specs~
    In-Ground 10,000 Gallons, Liquid Chlorine | Pump: Century 1.1HP HST110 | Filter: Hayward Cartridge CX900RE | Heater: Solar Roof Panels
    Cleaner: Dolphin DX4 (AKA "The Kraken")
    Test Kit: K-2006

Posting Permissions

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