I live in central Florida and use solar panels on my roof to heat my 15K gal. in ground pool to 86 F effectively March-October. I am considering adding a propane heater to allow use the rest of the year. I am assuming I can add the gas heater in line last, but don't know how to control it for best heat. I think a remote sensor in the water line before the solar panels makes sense, but don't know if that is possible or practical. Or would I need to switch between the systems? I would appreciate any suggestions about how best to do this. (Pool only, no spa.) TIA.
Can I add a propane heater to existing solar heat?
- Thread starter ChuckBruns
- Start date
I'm also in central florida, I'm sure you can add a propane heater, but wondered if you are using any type of a cover? I use a simple bubble cover and reel and my pool is consistently in the 80's from March to December (currently 84 today will probably see 86 before afternoon clouds and rain are predicted) , and off and on in Jan-Feb (last year my January high was 90). Running a heater without any kind of cover is kind of like heating a house with all the doors and windows open...
I would close off the solar panels during the cool months and not even pass any water thru them. If you didn't, you could be cooling off the pool more than adding heat to it. Yes you would have the panels first after the filter and then thru the gas heater and into your pool. Unless you have an automation system, you will be manually switching between each source. An automation system is the true way to have the water temp monitored and then the heat source turned on automatically based upon that temp you want to maintain. Most folks do use a solar cover when heating like this so they don't waste much of their money they just invested in heating the water.
Thank you BasicTeK & ps0303 for your feedback. Just to clarify, my solar heat has an auto switch based on the pool water inflow to the filter and it maintains the temp perfectly, so it won't cool inadvertently. I also have used a solar cover in the past and didn't like reeling it on and off for just a few hours a day, the additional propensity for algae, cleaning the cover, storing it for the summer, and the fact that covers deteriorated in about 18 months and needed replacement, even under warranty. Plus, I can afford the cost. So let me restate my question: Can a propane heater access a remote sensor (like the one on the solar auto switch) instead of being activated by it's in line sensor? That way I can let my solar panels preheat the water when there is enough sun so I save a little money and my system would be completely automated. Or is the solution only to use solar or gas, but not both at the same time? Or is there another solution?
- Jun 7, 2017
- 9,057
- Pool Size
- 29000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Aquapure 1400
Do you have automation? My heater is controlled by the iAqualink temperature sensor which is on a long cord and could be placed anywhere you want. By itself (not controlled), it uses its internal temp gauge.
You can use both but you're going to need to switch the heater on manually unless you have an automation system. Heaters have their own temp sensor and if you were to leave the unit in the on position, it would maintain the water temp per your setting. So if the pump kicks on and the water is cooler than the temp you set on the heater, the heater would light up and run till the water was to temp and then it would maintain it.
Thanks for the replies, everyone. I'm assuming by "automation" you are referring to the electric valve with controller and its temperature sensor that switches the water flow through the solar panels or not. Yes, I have it. I guess I need to find out if that same sensor, or a duplicate, can be slaved/connected to a propane heater (eg. Pentair MasterTemp 250) to override its internal sensor. I'll ask Pentair support as well as anyone in here who might know that answer.
- Jun 7, 2017
- 9,057
- Pool Size
- 29000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Aquapure 1400
I don't know how Pentair does it, but when a heater is interfaced with iAqualink, the control system and the temp gauge in the automation center is what is used to cycle the heater on and off. Correctly set up, the system could determine what heat source to turn on (and any associated valves). Any heater you want to add to your system it would help to have it compatible with your automation system. My system has both an air temp and water temp. So if it were too cold, the solar would not be utilized. Gas heat doesn't care about ambient temp only the water temp. BTW: It is more than the valve it is the entire automation system.
When we talk about automation we are referring to something like a Pentair Easytough or similar system. As for your solar control, I am not sure it can be used to turn the heater on.
It is not advisable to attempt to override the heaters temp sensor.
What controller do you have?
What pump do you have?
If you get an automation system like EasyTouch, it can control the solar and gas heater and you can select "Solar Preferred" to have the system use solar when available and gas as a backup.
What pump do you have?
If you get an automation system like EasyTouch, it can control the solar and gas heater and you can select "Solar Preferred" to have the system use solar when available and gas as a backup.
First, based on questions and FYI, my controller is a Hayward Aquastar II solar controller. The pump is high speed and I use a Pentair CC 150 filter. I run my pump & filter from 10 AM to 4 PM in the winter and to 5 PM in summer, so that is my only heat opportunity time. Essentially, it's a set and forget system, but it is an electronic timer with 4 on/off cycles available each day, so I could program it many ways. My solar control has two temperature sensors (thermistors), one on the pipe flowing from the pool to the pump (is this water too cold?) and one up on the pipe flowing from the solar panels (is this water hot?). Both sensors have wires to the controller where the first temp can be set (eg 86F). If both sensors say "yes," the controller opens the valve so that water flows through the solar panels. When the pool water reaches 86F or the roof water gets too cool, it closes the valve. It works great from mid-March to early November. So far so good.
Now, to use the pool year round, if I put a second heat source, like a gas heater with a built in sensor, in line after the solar panel out-pipe, then the gas heater will never turn on when the sun is shining because it will always sense warm water, even though the pool water is <86F. To avoid this, I need to tell the gas heater the actual temperature of the pool water. This is what the first sensor in the system already provides. I could install a new one next to it in the pipe and connect it to the gas heater if the gas heater accepts an external sensor. That's the key question! The only thing I want to connect to the gas heater is an external thermistor installed on the inlet pipe. I do not want an automation system for pool, spa, lights, etc. I also don't want the gas heater in line first and then run hot water up through the solar panels.
I am assuming I could still set the temperature on the gas heater wherever the sensor is. This would make a fully automated system allowing solar heating when the sun is sufficient and secondary heat from the gas heater when the solar can't maintain the set temperature. It would also heat the pool a lot faster whenever the pool falls below the set temp. It would seem that if heaters can connect to automation systems, they should be able to do this, even if it's a post install bypass circuit done by the tech who installs it. Does this make sense, or am I missing something?
My alternative would be to have a manual valve to switch between solar and gas depending on the time of year. Sorry for being verbose, but I wanted to get it all out there.
Now, to use the pool year round, if I put a second heat source, like a gas heater with a built in sensor, in line after the solar panel out-pipe, then the gas heater will never turn on when the sun is shining because it will always sense warm water, even though the pool water is <86F. To avoid this, I need to tell the gas heater the actual temperature of the pool water. This is what the first sensor in the system already provides. I could install a new one next to it in the pipe and connect it to the gas heater if the gas heater accepts an external sensor. That's the key question! The only thing I want to connect to the gas heater is an external thermistor installed on the inlet pipe. I do not want an automation system for pool, spa, lights, etc. I also don't want the gas heater in line first and then run hot water up through the solar panels.
I am assuming I could still set the temperature on the gas heater wherever the sensor is. This would make a fully automated system allowing solar heating when the sun is sufficient and secondary heat from the gas heater when the solar can't maintain the set temperature. It would also heat the pool a lot faster whenever the pool falls below the set temp. It would seem that if heaters can connect to automation systems, they should be able to do this, even if it's a post install bypass circuit done by the tech who installs it. Does this make sense, or am I missing something?
My alternative would be to have a manual valve to switch between solar and gas depending on the time of year. Sorry for being verbose, but I wanted to get it all out there.
There is a temp sensor in the heaters so no real need for an additional one. Since you are heating year round, just power up the heater and leave it on POOL and set to the temp you desire. Then when the pump kicks on it will trigger the pressure switch in the heater to allow the unit to fire up and run IF the water temp is cooler than your set point. It will run until the water is at the correct temp you set on the heater and it will maintain it. The solar panels, especially in the cooler months, aren't going to put out much heat to begin with. If you have them on during a day like we have been having, cooler temps, you're cooling the pool more than warming it up. So they should be closed off. I always advise owners to turn solar panels off during cooler months and just use the gas heater.
Many people run their pools like this that want to heat it year round. No need then for extra controller or anything. You can add a fireman's switch to your timer so that if the heater is running and it's time for the pump to shut off, it will turn off the pool heater 20 minutes before pool pump. This allows the heater to cool down before the pump shuts off.
When you have a heater combined with solar, the gas heater should always be installed AFTER the solar panels, last. But again, having the solar on in the cooler months will cool your water.
So, no need for any extra equipment other than a fireman's switch on your timer clock. The pool heater will monitor the water temp and come on when needed based upon your temp you set on it.
Many people run their pools like this that want to heat it year round. No need then for extra controller or anything. You can add a fireman's switch to your timer so that if the heater is running and it's time for the pump to shut off, it will turn off the pool heater 20 minutes before pool pump. This allows the heater to cool down before the pump shuts off.
When you have a heater combined with solar, the gas heater should always be installed AFTER the solar panels, last. But again, having the solar on in the cooler months will cool your water.
So, no need for any extra equipment other than a fireman's switch on your timer clock. The pool heater will monitor the water temp and come on when needed based upon your temp you set on it.
Paul, I have a feeling we are not on the same page. I understand everything you said, but 1) My solar controller won't allow the water to cool if the temp on the roof is too low, since it automatically bypasses the panels in that case, so that is not a problem for me. 2) My concern is that when there is just enough sunshine to trigger the solar controller to allow solar heating, the solar heated water will be warm enough to defeat the internal sensor in the gas heater, but not provide enough heat to warm the pool adequately. For example, if I set the heaters to 86F, I might get 92F water flowing from the solar which would not turn on the gas heater and, by itself, would not make a dent in the pool temp in January. This is why I want to add gas heat in the first place.
I agree with you that turning off the solar completely would prevent this problem, but I still would like to know if there are gas heaters with plug-in remote sensor capability so that I would get the most efficient heating under all conditions. I also believe that I could get under the gas heater cover and rewire it to a remote, but I would rather not perform modifications that would effect any warranty. I am just trying to figure out all my options before starting this project. Thanks again for your help and expertise.
I agree with you that turning off the solar completely would prevent this problem, but I still would like to know if there are gas heaters with plug-in remote sensor capability so that I would get the most efficient heating under all conditions. I also believe that I could get under the gas heater cover and rewire it to a remote, but I would rather not perform modifications that would effect any warranty. I am just trying to figure out all my options before starting this project. Thanks again for your help and expertise.
No, there is no heater that would allow you to add another temp sensor like you are thinking. The heater has it's own and no additional items other than a automation system can be attached to the heaters.
I believe you are over thinking how this all works and that is where the confusion is. I've been in the business now 10+ years and I have never seen or heard of any set up that you are trying to attempt. Also, there is no way in January you will get any kind of measurable heat out of the solar panels, especially 92 degrees. That is a summer time temp. MAYBE the only way you would get that type of temp out of solar panels is if the water sat in the panels for while, not flowing thru, and then the system came on and the standing water was pumped out of the panels. It would be an initial surge of warm water but the cool pool water would push that thru rather quickly and then you are back to cold water which if cooler than your heater set temp, it would cause the heater to fire.
I can assure you that they way I have described the process is the way it works for everyone. Everyone I work for that has solar, turns them off/down/lower temp whatever, during the "winter" months and they use gas heat exclusively when they want to heat.
I believe you are over thinking how this all works and that is where the confusion is. I've been in the business now 10+ years and I have never seen or heard of any set up that you are trying to attempt. Also, there is no way in January you will get any kind of measurable heat out of the solar panels, especially 92 degrees. That is a summer time temp. MAYBE the only way you would get that type of temp out of solar panels is if the water sat in the panels for while, not flowing thru, and then the system came on and the standing water was pumped out of the panels. It would be an initial surge of warm water but the cool pool water would push that thru rather quickly and then you are back to cold water which if cooler than your heater set temp, it would cause the heater to fire.
I can assure you that they way I have described the process is the way it works for everyone. Everyone I work for that has solar, turns them off/down/lower temp whatever, during the "winter" months and they use gas heat exclusively when they want to heat.
- Jun 7, 2017
- 9,057
- Pool Size
- 29000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Aquapure 1400
Is it money that prevents you from going with automation? I have my own views on solar as I think it is a system that will never pay for itself (no ROI). Most solar returns that I have seen are with lots of sun and using a solar cover to stop heat loss. I suspect if you didn't use the solar at all in these situations you would get just about as much added heat as the solar array (Sun, warm temps, solar cover). For me, if you are going to heat the pool, HEAT the pool! Gas! Let it burn baby! But that is for another thread!
I used to have a heat pump. It was noisy and needed to run for many hours in the cool months. I have SE exposure, so solar paid for itself in a few years with a large reduction in my electric bill, so I did have a good ROI. I have no spa and just want the pool maintained at 86F. Money isn't an issue, but I don't throw it away. What are the benefits of automation?