Solar vs Electric Hot Tub Heater: Which One Should You Buy?

Solar vs electric hot tub heater at a glance

What an hour of electric heat costs

Running cost comes from listed wattage and the local electricity rate. The 18KW example draws more power than the 11KW example while it runs, so it costs more per hour at the same rate. Check the rate on the electricity bill before budgeting, since rates vary by supplier and plan.

Both listings state that the heater cycles on and off around the set temperature, so a heater holding warm water costs less per hour than a heater warming cold water from scratch. The 18KW example draws more power while it runs, and its bullets list it for a larger volume, so the cost per soak depends on tub size and starting temperature, which the listings leave unclear.

Install, space and power

Both heaters are 220V and hardwired, and both listings state that a licensed electrician must handle the install. That sets the electric route apart from solar at once: the heater needs a suitable circuit before the water is heated, not just a sunny spot.

Size needs a careful read. The spec table on each listing gives two different size sets, 17.0 inches x 2.0 inches x 10.0 inches in one field and 3.94 x 17.72 x 13.39 in another, so measure the space against the listing and confirm which set is right before ordering. Both listings give the same part number, WJW11, although the models differ, PHS-110 and PHS-180.

Water volume is where the two examples part ways. The 11KW example lists around 1300 gallons. The 18KW example lists around 2000 gallons in its bullets but 1300 gallons in its title, so treat the larger figure as unconfirmed and match the heater to the tub with the smaller figure in mind. The hot tub heater for stock tank roundup lists more heater options.

Upkeep and water care

Both listings carry the same salt chlorinator tip: place it downstream of the heater outlet, at least 2m (6.6 ft) from the thermostat, and avoid saltwater to prevent heating element corrosion. The touchscreen shows the temperature and switches between F and C, and the heater cycles on and off to hold the set temperature. Neither listing states a filter, a pump, or a cleaning routine, so plan water care around the tub and its own equipment.

Gear for each route

These are scored on the Chill Score: performance, build, value, safety certifications and warranty. Neither listing states a UL or ETL listing or a warranty term, so both score 0 for safety and 0 for warranty.

Scores run from 9.2 to 9.8: each product’s point total is placed on that range, so more points always means a higher score.

Choose solar if

• You have a sunny spot for panels and pipe runs near the tub.
• You heat the tub mainly in sunny weather and can plan soaks around the sun.
• You want the heat itself to come from sunlight rather than a paid supply.
• You accept that no solar pick is scored here, since no solar listing was in the set.

Choose electric if

• You want warm water on demand, in any weather, at a set temperature.
• You have a 220V hardwired circuit installed by a licensed electrician.
• Your tub matches a volume listed here: around 1300 gallons for the 11KW example, or around 2000 gallons in the 18KW example’s bullets.
• You accept paying for electricity while the heater runs.

Check Your Space First

• Confirm a 220V hardwired circuit and a licensed electrician for the install, since neither heater plugs into a standard outlet.
• Measure the space against the listed size, and confirm which of the two size sets in the spec table is right.
• Match the heater to the tub volume: around 1300 gallons for the 11KW example, and 1300 gallons in the title or around 2000 gallons in the bullets for the 18KW example.
• Keep a salt chlorinator at least 2m (6.6 ft) downstream of the thermostat, and keep saltwater away from the heating element.

Common questions

Is a solar heater enough for a hot tub?

That depends on sun exposure and the tub, and this article cannot answer it from a listing, since no solar heater was in the set and no solar pick is scored. The two examples here are both electric, so the solar side is covered as a general choice. A reader who wants a scored solar pick should wait for an article built around solar listings.

How much does it cost to run an electric hot tub heater?

It depends on the listed wattage and the local electricity rate. The 18KW example draws more power than the 11KW example while it runs, so it costs more per hour at the same rate. Both heaters cycle on and off around the set temperature, so holding warm water costs less per hour than warming cold water from scratch. Check the rate on the electricity bill before budgeting.

Do I need an electrician to install a hot tub heater?

Yes, for these examples. Both listings state that the heaters are hardwired and that a licensed electrician must handle the install. That applies to the 220V circuit, not just the heater itself. Do not wire a high power heater without one.

What temperature do these heaters hold?

Both listings state a control range of 77 to 122 F on a touchscreen, with switching between F and C. The heater cycles on and off to hold the set temperature. Neither listing states how long a cold tub takes to reach the set temperature, since heating time depends on tub size, temperature increase, heater power and air temperature.

Can I use a salt chlorinator with these heaters?

The listings carry a tip for it: place the chlorinator downstream of the heater outlet, at least 2m (6.6 ft) from the thermostat. They also say to avoid saltwater to prevent heating element corrosion. That tip appears on both listings, so treat it as part of the install plan.

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