Can you keep Spa open in winter on a shared system if pool is winterized

MDpool21

Member
Mar 22, 2021
12
Clarksville, MD
We are building a pool and a separate raised spa that will be located 5 feet from our pool. We had planned on 2 separate systems so we could use the spa all winter and heat both the pool and spa to different temperatures at the same time during the spring and fall. However, due to the extra space required for a second system, our pool builder suggested we use a shared system (gas heater).
He said we could winterize our pool in October/November and keep just our spa open all winter by putting it in spa mode. Is this true? Are there any problems with doing this? Will winterizing our pool and putting our heater in spa mode prevent all water from going into the pool pipes? I am concerned about freezing pipes. We will be getting a generator for our spa in case the power goes out in the winter.
Are there any other issues I should be aware of with using a shared system where the spa is separate from the pool (so no overflow)?

Also, in the spring/fall if I heat my spa to 100 degrees in spa mode and then switch to pool/spa mode will the temperature of my spa go down (does the cold pool water mix with the hot spa water in pool or pool/spa mode)? Is there any way I won’t have to heat my spa from 80 to 100 every time we want to use the spa. We will cover our pool with an autocover and our spa with a normal cover at night.
I assume I will need to keep our system in pool/spa mode at night to filter and circulate the pool and spa, so I will either have to heat both our pool and spa to 80 degrees through the night or not heat either at all during the night. Either way I assume it will drop my spa temperature a lot each night.

Do they make gas heaters/shared systems where you can heat the pool and spa to different temperatures at the same time?

Thank you in advance for any advice/answers you can give.
 

MDpool21

Member
Mar 22, 2021
12
Clarksville, MD
Could someone please tell me if I need the Pentair Intellicenter, Intellitouch, or Easytouch 8 dual body control system?

We will have a pool and separate raised spa that is 5 feet from the pool. They are supposed to be on a shared heater/system. We plan to close our pool for the winter, but keep our spa open all year.

We plan to have:

Pentair Intelliflo VSF Variable speed pump variable speed pump
400,000 BTU Pentair Mastertemp gas heater
Pentair Clean&Clear 420 Cartridge Filter
Pentair Intellichlor IC-60 salt/chlorine Generator
a second pump for the spa (20 back/calf/foot jets)
3 bubblers with separate valves
4 led laminar jets
a slide
a river flow swim current
a river flow whitewater current
lights in the pool and spa
IntellipH
Auto pool cover
Auto Fill

Thanks!
 

Jimrahbe

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Jul 7, 2014
21,277
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21,

Let's see if we can get some input from some of our northern pool and spa owners...

I'm in Texas and know nothing about closing a pool, but just in the short period of time that we had our recent freeze, I' not sure how keeping half the pool/spa open would work.

It seems to me you would have to keep the spa water moving 24/7 to prevent the spa equipment from freezing up.. :scratch:

I'll be interested in how this turns out..

Let's see what Allen says about how he uses his pool and spa in the winter.. Calling @ajw22

Thanks,

Jim R.
 

cowboycasey

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Jul 3, 2013
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Southern OK
Your going to hate me but here it goes.... I would rather save you massive amounts of money and you enjoy your hot tub all winter than to find out afterwards...

Get a stand alone hot tub and use it all winter long...

If we all learned something from the great freeze of 2021 is pools and spa in freezing temps do not work.. You have no way to ensure you can keep power to the spa in freezing temps. In temps colder than 50 degrees you can not (are not supposed to) run the gas heater. so there will be no way to heat the spa in temps colder than 50 degrees... (I did not know this until all the carnage happened 3 weeks ago)

I guess it is less risk just heating the spa but I think it would get very expensive heating it every day above 50 degrees even if your not using it...

Here is a thread from a couple years ago..

Another one from the recent freeze
 

ajw22

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You say your spa will be 5 feet from the pool. Will the spa have a spillover to the pool or other way to return water from the spa to the pool?

Pentair automation is designed to manage a pool/spa that is interconnected with a spillover. If that is not going to be your plumbing setup I would like to understand how your builders intends to share your pump/filter/heater between the two.

Will your spa be covered and insulated for year round use?

Will your equipment be outdoors or indoors?

MD is a bit warmer climate then NJ. Resorts have spas open all year round. However they have to be designed differently then a summertime pool/spa design.

Tell us what steps are being taken in your design for 12 months use of your spa?
 

MDpool21

Member
Mar 22, 2021
12
Clarksville, MD
There won’t be a spillover from the spa to the pool since it will be 5 feet away. Our pool builder plans to use overflow lines to return water from the spa to the pool. I think everything else would be the same as in a normal shared system with a spillover.
I was told a natural gas heater would work in freezing temperatures, but a heat pump wouldn’t. I think we will have to keep our spa heated all winter to at least 60-80 degrees and then turn it up to 100 degrees when we want to use it. We will have a generator for the spa in case the power goes out. We plan to cover our spa with a normal spa cover (not an auto cover). I don’t think there is any other insulation for the spa.
Our equipment will be outdoors.
I was told that when we close our pool for the winter we would keep the system in spa mode so only the spa is heated. The pipes in the pool would be cleared of water so they don’t burst in freezing temperatures.
 

jimmythegreek

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This can be done but I dont recommend it. First a concrete spa has poor insulation. They dont work anywhere close to what a standalone spa does for hydrotherapy, again not even close. 2nd the cost of gas heater is going to be hundreds each month. 3rd you have to be very careful to not accidentally allow water past a valve to the pool and freeze damage pipes. The generator is great, but what happens if pump goes bad or heater dies a year or a few down the road in middle of winter? For probably less money a luxury hot tub can be placed that will cost you less than 50 a month in dead if winter, 10 max I summer, amd is ready to go at 100+ degrees 24/7. You can get some sweet exteriors nowadays with LED, stonework, whatever you wallet likes. And if it dies yiu have days before water freezes, even then a small heater in equipment bay can buy you lots of time
 

ajw22

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I agree with my neighbor @jimmythegreek. But if you insist on continuing here are some other things to think about...

There won’t be a spillover from the spa to the pool since it will be 5 feet away. Our pool builder plans to use overflow lines to return water from the spa to the pool. I think everything else would be the same as in a normal shared system with a spillover.

The overflow lines are the equivalent to a spillover. Where the overflow line intake is placed will define the water level of your spa. Make sure it is adequate for you as we have had folks with that design who were not happy at the low water level of their spa.

Will the overflow lines be open in the winter when the pool is closed?

How will you handle spa overflow or spa water evaporation loss when the pool is closed. These things are handled automatically when the pool is open and the pool and spa are connected.

I was told a natural gas heater would work in freezing temperatures, but a heat pump wouldn’t. I think we will have to keep our spa heated all winter to at least 60-80 degrees and then turn it up to 100 degrees when we want to use it. We will have a generator for the spa in case the power goes out. We plan to cover our spa with a normal spa cover (not an auto cover). I don’t think there is any other insulation for the spa.

Running the heater in cold weather with water temperatures below 68F can cause corrosive condensation in the heater exhaust.

The Pentair MasterTemp Heaters say:

- Operating this heater continuously at water temperatures below 68° F. (20° C) will cause harmful condensation and will damage the heater and void the warranty.
- When starting the heater for the swimming season with a water temperature below 50° F (10° C), the heater may be used to heat the water; however, make sure that the heater operates continuously until the water temperature reaches the heater’s minimum setting of 68° F (20° C).

The Hayward H-Series heaters say "Do not use the heater to maintain the water temperature just above freezing or for freeze protection."


Our equipment will be outdoors.

The Texas freeze this year showed that even when people left their pump running 24/7 some still had freeze damage in areas that did not have good water flow. A lot of thought needs to be given to your plumbing to ensure you do not have freeze prone areas. This is not something a typical pool plumber considers.

I was told that when we close our pool for the winter we would keep the system in spa mode so only the spa is heated. The pipes in the pool would be cleared of water so they don’t burst in freezing temperatures.

Has your pool builder done setups like you describe for others? How many has he done?

While it sounds simple in practice things don't work that perfectly in real life. Valves don't always seal perfectly and can leak water into your closed pool pipes and then freeze. Over time you are likely to have problems in the winter for one reason or another.

We advise on how to have a trouble free pool and what you are building is not likely to be trouble free.
 

MDpool21

Member
Mar 22, 2021
12
Clarksville, MD
I appreciate all of your comments and advice. We are very frustrated as we had asked for and planned on having 2 systems from the beginning for all of the reasons you listed.

I know the portable spas are much better in terms of number of hers and insulation, but my husband prefers the look and customization of the gunite spas. We have a big family/extended family so we plan on having a 9’ x 9’ raised spa (12’ x 12’ including walls) that can fit 10-11 people and I can’t find portable spas that big. If you know of any companies that make them that big please let me know.

Our pool builder said he would cap the over flow lines in the winter to stop the flow of water into the pool. But I am worried about small leaks. I know he has done at least 2 other spas like what he is proposing for us since he offered to bring us to look at them. But I don’t know how many he has done altogether.

I will ask him about the overflow intake line placement. Thanks for mentioning that.

What is the smallest footprint needed for a separate system for the spa? We already have a 4x12 equipment pad for the pool/spa and he said we would need another 4x8 pad if we do a separate system for the spa.
 

ajw22

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What is the smallest footprint needed for a separate system for the spa? We already have a 4x12 equipment pad for the pool/spa and he said we would need another 4x8 pad if we do a separate system for the spa.

Depends what specific equipment you are using and how close you jam things together.

 

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JJ_Tex

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That is certainly not a standard setup. One of the purposes for the spillover is to allow leaves and such that fall into the spa to float over the spillway so they can be captured by the pool skimmers.

Will you have a skimmer also in the spa since you will not have a spillover?
 

cowboycasey

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There are many swim spa/hot tub combos out there.. You can call them and ask if they do just hot tub.. :)

this one is 20 feet long but the hot tub size is only a 6 person..

This 15 foot one can seat 14 and be used as a hot tub or small pool

swim-spa-sq1.png

outside of spa
Brown-stacked-stone-300x300.jpg
 

MDpool21

Member
Mar 22, 2021
12
Clarksville, MD
That is certainly not a standard setup. One of the purposes for the spillover is to allow leaves and such that fall into the spa to float over the spillway so they can be captured by the pool skimmers.

Will you have a skimmer also in the spa since you will not have a spillover?
I don’t think he was planning on having one. Good point.
 

jimmythegreek

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If you are going to go this route the plumbing needs to have a design to completely bypass the pool with double valve isolation. And you need to really learn what is what amd why it is there. If you have an issue PB may not be on call to help.
The larger spas amd swim spas are great, no comparison. My biggest issue with all this is the need to plan use. I have a standalone hot tub, I just got out of it. Had no plan to use it but had a rough day digging a pool amd got beat up. If I had to go outside amd heat the water and wait I'd be asleep already amd said screw it. Not to mention the gas bills
 

cowboycasey

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I was thinking about this last night and I think you can have what you want... I will not be easy to do you just have to do it right..

1. Make your hot tub a stand alone system complete with its own pump, filter, skimmer, and heater.
2. put your pump and all equipment in a heated shed. (you said you have a whole house auto backup generator)
3. your hot tub will be set up like a big pool, just heated with jets.
4. use an electric heater or 2 to keep the temp up to 104 or whatever temp at all times.
5. bury all pipes 6 inches below the normal frost line
6. use some kind of foam or something else for insulation around the hot tub during install to keep heat in and cold out.
7. get a 6 inch custom cover, beyond nice makes custom covers like this.. Oversized Spa Covers | Large Hot Tub Covers | BeyondNice
8. make the hot tub a rectangle not round to be able to have a cover.

In the winter if anything happens and the temp falls below 50 degrees have a way to winterize the system fast.. The problem people in Texas found is it went bad fast and freezes within hours... The more insulation you can have the less it will cost to keep heated...

I grew up in Oregon and they had giant hot tubs like this, they did not have covers.. It was a great big heated hot tub that they kept at 100 degrees at all times so I know it can be done.. I can only imagine the cost to keep it going but it was a very expensive resort..

You could also have a gas heater connected to it, not sure the most efficient way to do it, gas or electric....
 

jseyfert3

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We have a big family/extended family so we plan on having a 9’ x 9’ raised spa (12’ x 12’ including walls) that can fit 10-11 people and I can’t find portable spas that big. If you know of any companies that make them that big please let me know.
Not quite that big, but close. This one is 8-9 people. Saw this one in person at a local dealer actually. It made our 6 person one seem tiny!
 

sl7vk

Active member
Jan 6, 2021
38
Salt Lake City, Ut
Everything the OP described is what is currently being built in my backyard right now.
Spa does have a skimmer.
I'd prefer to keep it open in the winter, and my PB has told me that wouldn't be an issue. Cost of gas, would be high no doubt.
My spa is only 6 x 8 and fully in ground detached.
One set of equipment.
I'm told that is not an uncommon setup here in Utah. I imagine that things get colder here than in MD.
 

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