Should you winterize a hot tub?

Yes, and the makers lean that way. A powered tub circulates and heats, which is what keeps its plumbing from freezing. Jacuzzi says its tubs protect themselves automatically when operating, and that in bitter cold below 32°F owners should set the main filter cycle to run 24 hours. Master Spas says an empty tub should never sit below 0°F; if it will, keep it filled and running. If the display shows ICE, that is freeze protection running the pumps, not a fault; see the hot tub ICE code.

Watch for anything that stops the circulation. Hot Spring warns that clogged filters can trip the circulation pump's cut-off, so keep them clean through winter. Clear snow off the cover, which can break the foam core. After a power cut in a hard freeze, check that the tub came back on.

More than draining. Water left in the pumps, heater and lines has to come out, which Hot Spring does with a wet/dry shop vac blowing out each jet line, then non-toxic propylene glycol antifreeze, never automotive ethylene glycol. Master Spas' steps include opening the equipment area and loosening pump unions. That is equipment-bay work, and Hot Spring and Jacuzzi both recommend a dealer.

Flush out the antifreeze before you use it. Hot Spring's opening steps fill the tub, superchlorinate at twice its normal amount to break down the glycol, then drain and refill; a defoamer may be needed. Master Spas says to flush the system thoroughly if antifreeze was used. Then follow hot tub start-up.