Depending on where you live, your pool season may last as little as 3-4 months. For many people in a northern climate, June – August are prime swimming months but by the time September rolls around and kids are back in school, the weather starts to turn, leaves begin to fall (no pun intended) and thoughts of closing your pool for the winter abound. A pool heater can’t change the weather but may extend the pool season slightly and help you get better use of it while you can.
Salt water pools are just like chlorinated pools and can be heated with the exact same methods. The same gas, propane, solar and heat pump heaters that work for a chlorine or bromine pool will also work for your salt water pool. They are attached to the pool system in the exact same way and there is no difference at all.
One of the biggest myths about salt water pools is that they don’t contain or use chlorine, but they do. A salt water pool creates its own chlorine from salt. So salt water pools are also chlorine pools because that’s what a salt chlorination system does: It electrically converts salt to chlorine to sanitize the pool and keep it clean for swimming.
From a heating perspective, salt water pools are exactly the same as other chlorinated pools.
Pool Heating Options
As mentioned above, you have the exact same heating options for a salt water pool as you have for a chlorine pool:
Gas or propane heater
A gas heater is typically installed next to the pool equipment and is attached into the system so that water runs through the heater and through existing pool piping before being returned to the pool. A gas heater is attached to an underground gas line. A propane heater would use a propane tank that needs to be filled when it is empty similar to a barbeque propane tank.
Using a pool heater attached to a gas line ensures that there is always a constant flow of gas to the heater and no tank to refill or replace. It’s by far the most efficient and easiest pool heating option since a gas pool heater directly heats the water and provides on demand heating whenever you want. You need access to a gas line for this type of install which may add to the cost.
A decent gas pool heater may cost $1,500 – $5,000 to buy and install depending on the size, brand and model and gas line availability.
Solar heater
A solar heater uses the sun’s rays to heat pool water and is typically comprised of several parts. Solar panels are installed normally on the roof of your house and piping runs up and down part of the house to provide water flow up to the roof where the sun’s rays can heat the water before returning it to the pool. Obviously a solar heater only works when there is sufficient sunlight and you need a pump strong enough to push water vertically to the roof of your house.
So you can’t heat a pool overnight when it’s dark as you can with a gas heater. Some people may consider the piping and solar panel equipment to be an eyesore if it’s visible running up the house and on the roof.
A solar heating system may cost $4,000 to buy and install.
Heat pump
A heat pump system is a newer form of pool heating that tends to work well in warmer climates that generally see temperatures above 45 degrees. A heat pump uses a compression system to transfer heat from a condenser to cold pool water to heat it up. The system runs on electricity so you will need access to an electrical connection to use this system.
As with a solar heating system, you rely on warm/hot weather so it doesn’t necessarily provide on demand heating like a gas heater does.
A heat pump system may cost $2,000 – $5,000 to buy and install.
And to confirm, your salt water pool can use any of the three systems to heat your pool. The gas heater is the most prevalent heating system used by pool owners and is also the most direct since it heats water on demand at any time and isn’t reliant on the sun or outside temperature to function.
Adding A Pool Heater
Can you add a pool heater to an existing pool? Yes, with a few provisos.
Do you have room to do so? Our pool equipment was installed at rear of the backyard on the right hand side. Our pool was built by the previous home owner and a heater was included so they were able to plan for it. But if you are working with tight quarters already and have little space, you may have a bit of planning to do.
A Hayward H-Series gas heater has a width of 21″ and weighs 150 lbs. A Hayward heat pump heater is even larger at 30″L x 34″W x 37H” on the small end. Our backyard is landscaped with large rocks and we wouldn’t be able to fit this Hayward heat pump in to replace our gas heater as it’s too large.
Our neighbors on the other hand got a pool installed in their home years after buying their house. They chose to install their pool equipment on the side of the house which give them lots of room for everything including the heater. Because it’s located next to the house, their gas heater was easily hooked up to the gas line.
Our pool equipment was installed at the back of the house which means a gas line had to be run underground all the way to the rear of the backyard which means more $$$$.
You need more piping. Your pool heater will get incorporated into your existing piping. So pool water runs through the heater whether or not the heater is turned on at the time. But you need to add piping in and out of the heater that attaches to your existing pipe work. This work is typically done by the installer unless you have experience and knowledge how to do this yourself.
Again, the room that you have to work with might be an issue if your pool equipment is in tight quarters as it is.
Also remember that you need to pick a heater that matches your pool size. Bigger is better in the sense that your heating system needs enough BTUs (British Thermal Units) to heat the amount of water you have in your pool. The more BTUs you need the larger the heater might be in terms of its dimensions.
And it’s more expensive, too.
Salt Water Chlorination
A salt water pool has two main pieces of equipment that other pools don’t have:
Salt chlorination system – A computer essentially, which manages the salt production of your pool. It is a box that sits near the pool equipment and has various functionality depending on the brand and model that typically enables you to manage your pool centrally.
This may include a pump timer, real time salt monitoring, warnings and sensors to alert you to potential problems and an ability to manage other parts of your pool automatically including the heater and perhaps pool lighting and water features. Overall it manages the conversion of salt to chlorine.
Salt cell – The pool salt cell is a hard plastic tube that is installed after your pool filter. It screws into your existing pool piping and effectively becomes part of the system when installed. It has a series of titanium plates inside the tube and when water passes through it, it is electrified which has the result of converting salt water into chlorine.
Modern salt chlorinator systems can be set to produce just the amount of chlorine you need so while your pump might be running 8 hours per day, you may only need to have your chlorinator running for 50% of that time, for example. The rest of the time, water passes through the salt cell normally but with no chlorine being produced. The salt cell turns on and off to produce chlorine as per the setting you use.
Salt Chlorination Conversion
Can you convert a regular chlorine or bromine pool into a salt pool? Yes you can.
Is it difficult to do so? No, it typically isn’t. You can get the system professionally installed or if you’re handy, you can do it yourself.
The salt chlorinator system box is mounted and installed near the pool equipment and wired for power. A piece of the existing pool piping is cut out and the salt cell is fitted in between and screwed in to complete the circuit, after the pool filter. The salt cell is then attached to the chlorination system to complete the work.
Modern chlorination systems enable you to run your heater centrally and automatically through the chlorination system if desired.
If your salt chlorination system is hard wired which it probably is, you’re best served to get the work done by an electrician for safety and insurance reasons. I met a woman years ago who bought a house with her husband that had an existing pool. Several years after buying the house and in the middle of the pool season, the pump caught fire and caused significant damage. The investigation showed that the hardwired pump had been incorrectly wired, most likely by the previous home owner.
Fortunately insurance covered the damage which was in the thousands of dollars since the new home owners were unaware.
Conclusion
- A salt water pool system can use the same type of gas, propane, solar or heat pump pool heaters that a chlorine or bromine pool uses.
- A pool heater is installed after the pool filter just like other pool systems.
- Gas heaters attached to an underground gas line are the most prevalent pool heating systems since they provide on demand heating whenever you like including overnight and don’t rely on direct sunlight or heat like solar and heat pumps do.
- If you’re building a pool without a heater but plan to add one in the future make sure you account for this when choosing the location of pool equipment.
- Want to learn more about pool heaters? Check out this post to learn more about heating options for your salt water pool.