Become a TFP Supporter Welcome to our new server and new forum software. Pool School
Results 1 to 8 of 8

Thread: Pump and heater on the same electrical circuit?

  1. #1
    Junior Member
    Join Date
    May 2011
    Posts
    7

    Pump and heater on the same electrical circuit?

    I've mentioned this in another thread, but would like to attract more attention and get opinions.

    My pool installation is pretty old, so There's a 20 amp line running from the house to the shed, with two switches (one in the house and one in the shed), powering my 3/4 HP pump (11 amp). I am putting in a Hayward H250FDN heater tomorrow, which has electronic ignition and needs a little power to operate.

    I'm planning to have the pump and the heater connected in series, and have an extra cut-off switch for the heater. This way if I ever forget the heater running and I switch off the power from the house, the heater will also completely shut down together with the pump.

    PS. It is not cost effective to install a second power circuit for the heater.

    Do you anticipate problems?

    Thanks in advance!

  2. #2
    Senior Member mas985's Avatar
    Join Date
    May 2007
    Location
    Pleasanton, CA
    Posts
    6,465

    Re: Pump and heater on the same electrical circuit?

    I think you meant that the heater and pump will be wired in parallel on the same breaker/switch which is the way I have mine wired. Depending on the heater, this may actually be necessary since some heaters like mine turn on the exhaust fan when there is no flow rate. So if it was wire separately rather than together, the heater fan would turn on when the pump shuts off.
    Mark
    Hydraulics 101; Pump Ed 101; Pump and Pool Spreadsheets; Pump Run Time Study
    18'x36' 20k gallon plaster/gunite pool, 1/2 HP 2sp pump, Aqualogic PS8 SWCG, 420 sq-ft Cartridge Filter, 450 sq-ft EPDM Solar Panel, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

  3. #3
    Senior Member
    Join Date
    Dec 2009
    Location
    Central Massachusetts
    Posts
    2,575

    Re: Pump and heater on the same electrical circuit?

    The heater only draws 1 amp at 220VAC, 2 amps at 120VAC. No problem.
    14,000 gallon IG, Vinyl. Hayward 3/4 hp superpump, Penatair IC40 SWCG, Pentair automation, Hayward sand filter, Aqua Comfort heat pump, Hayward 400k Lo-Nox LP heater.

  4. #4
    Senior Member
    Join Date
    Mar 2011
    Posts
    2,999

    Re: Pump and heater on the same electrical circuit?

    I the pump is on a timer, you should use a timer that has a "Fireman's Switch". The Fireman's switch will turn the heater off 15 to 20 minutes before turning the pump off to allow the heater to cool down before the water flow stops.

  5. #5
    Senior Member In the Industry

    Join Date
    Mar 2011
    Posts
    273

    Re: Pump and heater on the same electrical circuit?

    Quote Originally Posted by JamesW
    I the pump is on a timer, you should use a timer that has a "Fireman's Switch". The Fireman's switch will turn the heater off 15 to 20 minutes before turning the pump off to allow the heater to cool down before the water flow stops.
    A "firemans switch" is less important than they used to be. Since they have removed the firebrick from the heaters, they retain less heat, so the fireman's switch is not really required anymore.
    20X40 30,000 gallon gunite pool

  6. #6
    Junior Member
    Join Date
    May 2011
    Posts
    7

    Re: Pump and heater on the same electrical circuit?

    Guys, need again some help. This morning they installed the heater and everything, but didn't wire it. The guy said I'll have to wire it myself. Here is a picture below, can somebody tell me how to wire this heater? It's an old installation, what I want is to put the heater in parallel with the pump. What do I need to hook up to what?


  7. #7
    Junior Member
    Join Date
    May 2011
    Posts
    7

    Re: Pump and heater on the same electrical circuit?

    Ok, well, I ventured with wiring this as I thought I should, and it seems to be working What I did was to wire the black (hot) wire of the heater to the same place where the hot wire for the pump goes, and same with the white. Of course, I put a little switch before the heater, as well as a GFCI Seems to be working and I'll be swimming tomorrow!!!! HAPPY!

  8. #8
    Administrator JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    34,658

    Re: Pump and heater on the same electrical circuit?

    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    TFP Admin. Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

Posting Permissions

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