Electric heater for hot tub/spa?

Jump to latest Follow Reply
P

pool2905

Member
Feb 9, 2021
8
Massachusetts
My parents have a gunite hot tub/spa. They have a gas hookup there but the gas heater was dying after one or two seasons so they stopped fixing it/buying new ones. They had a pool person come out and recommend an electric heater that can be unplugged and taken in after the season is over and my mom has asked me to look into it. The gas heater was for both the pool and spa but this electric heater will be solely for the hot tub/spa as they don't need the pool heated.

Any suggestions?
 
How many BTUs will the electric heater put into the water?

What volts and amps will the heater need?

How many gallons in the spa?
 
I thought the pool person who came out recommended a heater?
 
Last edited:
Look at these...

E3T – Raypak

Raypak Pool & Spa, Residential and Commercial Hydronic Products -
www.raypak.com www.raypak.com


Depending on the BTUs you need between one 240V 30 Amp breaker to three 240V 50/60 Amp breakers. (note the spec sheet says 40 amp breakers but the installation manual on page 7 says 50/60 amp breakers)

Not exactly a heater you plug into the wall.

Raypak electic Heater specs.png

18,767 BTUs will heat a 1,500 gallon spa at 1.5 degrees an hour.

92,128 BTUs will heat a 1,500 gallon spa at 7.3 degrees an hour.

Now go back to the pool guy and ask him what he was talking about.
 
Last edited:
ajw22 said:
Look at these...

E3T – Raypak

Raypak Pool & Spa, Residential and Commercial Hydronic Products -
www.raypak.com www.raypak.com


Depending on the BTUs you need between one 240V 30 Amp breaker to three 240V 40 Amp breakers. Not exactly a heater you plug into the wall.

View attachment 175317

18,767 BTUs will heat a 1,500 gallon spa at 1.5 degrees an hour.

92,128 BTUs will heat a 1,500 gallon spa at 7.3 degrees an hour.

Now go back to the pool guy and ask him what he was talking about.
Click to expand...
Thank you! I'll check them out. My parents had used a pool guy for an issue with the pump, but not someone they typically use(typically do everything themselves) who recommended it. There's an outlet out there in the pool pump area, but I don't know if it's able to power the heater.
 
How many amps electrical service does your mother's house have?

Can she provide 120 amps @ 240 volts?

pool2905 said:
There's an outlet out there in the pool pump area, but I don't know if it's able to power the heater.
Click to expand...

A standard outlet is 15 or 20 amps @ 120 volts.

You do not "plug in" high amp 240V heaters.

What I am leading you towards is that these electrical heaters are impractical for a normal house due to the electrical requirements. That is why they are rarely used except in new construction and commercial situations.
 
ajw22 said:
How many amps electrical service does your mother's house have?

Can she provide 120 amps @ 240 volts?



A standard outlet is 15 or 20 amps @ 120 volts.

You do not "plug in" high amp 240V heaters.

What I am leading you towards is that these electrical heaters are impractical for a normal house due to the electrical requirements. That is why they are rarely used except in new construction and commercial situations.
Click to expand...
Thanks! I'm actually not totally sure. She just basically asked me to research the best electric pool heaters. I do agree that a gas is probably better but she seems set on a electric. I'll try just steering her towards a gas heater. Thank you again for your help!
 

Enjoying this content?

Support TFP with a donation.

Give Support
pool2905 said:
Thanks! I’ve convinced her on gas. Are there any good small ones?

We currently have this which is broken but my mom feels it’s too big in size: Raypak Model 406A Electronic Digital Control Natural Gas, 399,000 BTU
Click to expand...

A Raypak gas heater is as good as you can get.

Digital – Raypak

Raypak Pool & Spa, Residential and Commercial Hydronic Products -
www.raypak.com www.raypak.com

There is no such thing as too big of a gas heater as long as you have the gas service to supply it. A larger heater just heats the spa to the desired temperature faster then a smaller heater. You use about the same amount of gas whether you heat the spa to the temperature quickly with a large heater or slowly with a small gas heater.

Raypak has gas heaters at 200K, 266K, 333K, and 400K BTUs.

What is not repairable on your Mom's Raypak heater? How old is the heater?

You may need to poke into why her existing heater failed. If it is due to water chemistry then any new heater will fail the same way.
 
  • Like
Reactions: jimmythegreek, Mdragger88 and RDspaguy
A 5.5 or 11 kw electric heater might be reasonable for a hot tub.

One problem with gas is that the temperature rise is about 17 degrees from inlet to outlet. If the water going into the heater is 103 degrees, the water coming out will be at 120 degrees, which is pretty hot.
 
Most spas (300-500 gallons) have a 4.0 or 5.5 kw heater at 240v. This requires a 30 amp circuit and #10 wire, and would struggle to heat a 1500 gallon tub in a timely manner. There are freestanding electric heaters, and 11Kw is an option on some reasonably priced units, but would need a 50 amp 240v circuit on #6 or #8 wire, depending on the distance from panel. That wiring cost could exceed the cost of the heater. And depending on your electricity cost (soon to skyrocket everywhere in the US) it could be very expensive to run.
 
  • Like
Reactions: jimmythegreek
RDspaguy said:
Most spas (300-500 gallons) have a 4.0 or 5.5 kw heater at 240v. This requires a 30 amp circuit and #10 wire, and would struggle to heat a 1500 gallon tub in a timely manner. There are freestanding electric heaters, and 11Kw is an option on some reasonably priced units, but would need a 50 amp 240v circuit on #6 or #8 wire, depending on the distance from panel. That wiring cost could exceed the cost of the heater. And depending on your electricity cost (soon to skyrocket everywhere in the US) it could be very expensive to run.
Click to expand...
I have a 240v 50 amp breaker and #8 wire to my hot tub 5.5kw heater , no big deal and not that expensive in the grand scheme of things.
 
A.O. said:
I have a 240v 50 amp breaker and #8 wire to my hot tub 5.5kw heater , no big deal and not that expensive in the grand scheme of things.
Click to expand...
In your case, perhaps. Some people have to get a service upgrade to have an extra 50 amps to work with. Or maybe the panel is on an interior wall in a finished basement and would need drywall and painting after you run the wire. An extra $1-2k may be "no big deal" to you, but in alot of "grand schemes" it's a huge deal.
 
Pools and spas are luxuries, not necessities.

People who have a concrete pool and spa are not just getting by. They have money or they would not be buying a heater in the first place.

A gas heater would be thousands to buy and install. So, there’s no savings there.

If $2,000.00 is a big deal to someone, they probably need to downsize to a place without a pool and spa.

In any case, it’s up to the person to decide what’s worth buying or not.
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply