Heater questions

pool123*

Well-known member
Aug 28, 2019
139
Aldie, VA
Hello everyone! We need some advice. We want to add a heater to our 2-year old pool. We are still trying to decide between a gas heater and a heat pump (subject for another post), but are surprised by the pricing we’ve received. Despite reaching out to several local companies to get quotes, only one responded. We never heard of them before - we found them because they left a flyer on our door about pool service- and have been unable to find any reviews or anyone locally who is familiar with them. They have, however, been very responsive. I have two questions:

  • Is installing a heater a complicated thing that we shouldn’t trust to a company we don’t know anything about? The will need to modify our plumbing to install the heater.
  • I have always thought that gas heaters were cheaper to install than heat pumps but that heat pumps were generally cheaper to operate. This company quoted us a Rheem heat pump model M8450TI-E-HC 140K heat/cool fully installed for $5515; a Rheem gas heater model P-M406A NG CU NI fully installed for $5225; and a Jandy JXI 400 NG Heater VF gas heater fully installed for $5081. I’m really surprised that there isn’t a larger price difference between the gas units and the heat pumps. Is this to be expected? Having no other quotes to compare to makes me a little nervous.
Thank you!
 
Caveat: I don't have a lot of experience, but have done much reading and asking people.
It isn't such a complicated job, but rather one where there's essentially one right way and a gazzilion wrong ones and mistakes that can cause all kinds of problems down the road. I'd definitely recommend hiring someone who has a good reputation for installing specifically the heater you choose. Manufacturer certification and evidence of past similar installs are a good start. At the same time, identify a tech who can do periodic maintenance correctly. Just as it's good to have your home heating system checked every year or two, it's good for the pool heater, too. This is probably the most expensive thing on your equipment pad. It pays (literally) to be thorough and careful.
 
…. We never heard of them before - we found them because they left a flyer on our door about pool service- and have been unable to find any reviews or anyone locally who is familiar with them …

HUGE RED FLAG 🚩

I suggest you keep searching until you can find someone reputable.

If you post pictures of your equipment pad as well as gas source and distances from the gas utility meter to your pad, folks can help you with sanity checks on the pricing.
 
We are still trying to decide between a gas heater and a heat pump (subject for another post),

Make it part of this post and keep all the details about your heater decision together.

Is installing a heater a complicated thing that we shouldn’t trust to a company we don’t know anything about? The will need to modify our plumbing to install the heater.

The devil is in the details. The plumbing for a heater is straight forward as long as you have room for it on your equipment pad.

The cost in a NG heater is the gas line install. A gas line can cost $10/foot or more.

What is the size of your house gas meter? You sure it can feed a 400K BTU heater?

Post a pic of the data plates on your gas meter.

How far is the run from the gas meter to your pool equipment?

The cost with a HP is the 50-60 amp electrical circuit.

Where does the electrical circuit need to be run from to the pool equipment for the HP?

This company quoted us a Rheem heat pump model M8450TI-E-HC 140K heat/cool fully installed for $5515; a Rheem gas heater model P-M406A NG CU NI fully installed for $5225; and a Jandy JXI 400 NG Heater VF gas heater fully installed for $5081. I’m really surprised that there isn’t a larger price difference between the gas units and the heat pumps. Is this to be expected? Having no other quotes to compare to makes me a little nervous.

The other wrinkle with a HP is to buy a HP that someone locally services and does warranty work on. There are companies who will install a HP but they do not service it. We have seen folks with HPs who cannot find anyone local to service them.

Aquacal, Built Right, and Gulfstream are good HP equipment. Lookup where they might have dealers in your area.

Confirm you do not have a spa.
 
Last edited:
Caveat: I don't have a lot of experience, but have done much reading and asking people.
It isn't such a complicated job, but rather one where there's essentially one right way and a gazzilion wrong ones and mistakes that can cause all kinds of problems down the road. I'd definitely recommend hiring someone who has a good reputation for installing specifically the heater you choose. Manufacturer certification and evidence of past similar installs are a good start. At the same time, identify a tech who can do periodic maintenance correctly. Just as it's good to have your home heating system checked every year or two, it's good for the pool heater, too. This is probably the most expensive thing on your equipment pad. It pays (literally) to be thorough and careful.
Thank you! I will say that this company shows up as authorized to install on the Rheem website, it's just that is all I've been able to discover about them.
 
The devil is in the details. The plumbing for a heater is straight forward as long as you have room for it on your equipment pad.
I am not confident that we have the space for a HP because I know they are large and we were only anticipating (at most) a gas heater at the time. The company we spoke with says there is room. I will post a picture tomorrow.
 
Make it part of this post and keep all the details about your heater decision together.



The devil is in the details. The plumbing for a heater is straight forward as long as you have room for it on your equipment pad.

The cost in a NG heater is the gas line install. A gas line can cost $10/foot or more.

What is the size of your house gas meter? You sure it can feed a 400K BTU heater?

Post a pic of the data plates on your gas meter.

How far is the run from the gas meter to your pool equipment?

The cost with a HP is the 50-60 amp electrical circuit.

Where does the electrical circuit need to be run from to the pool equipment for the HP?



The other wrinkle with a HP is to buy a HP that someone locally services and does warranty work on. There are companies who will install a HP but they do not service it. We have seen folks with HPs who cannot find anyone local to service them.

Aquacal, Built Right, and Gulfstream are good HP equipment. Lookup where they might have dealers in your area.

Confirm you do not have a spa.
Sorry-- I am not using the quote function properly I don't think. I didn't intend to have so many separate replies. The gas meter is about 5 feet from the pool equipment. I'm under the impression that the electrical circuit would just need to go to the electrical box that's already near our equipment. The installer who quoted us took pictures and sent them to their electrician who said it doesn't look like we would need additional electrical work to support the HP. No guarantees though.

I will look into Built Right and Gulfstream, thank you. I have not had any luck getting any info from any Aquacal dealers in our local area, or from Aquacal directly.

We do not have a spa.
 
Best case a 140K BTU heater will heat a 40,000 gallon pool 0.42 degrees per hour. That is best case at 80F and 80% humidity. As the temperature and humidity drop the HP output will decrease.

A 400K NG heater will heat a 40,000 gallon pool at 1 degree per hour in any temperature conditions.

You must use a solar pool cover to retain the heat a HP creates for it to be at all practical for you. If you don't use a pool cover then forget about a HP.

Raypak Gas Pool Heater Sizer​

Raypak has a Gas Pool Heater Sizer. It tells you the Temperature Rise/Hr and Natural Gas and Propane costs to heat a pool in your local area to selected temperature by month. Adjust the natural gas cost and propane cost in the lower left to your local gas prices for accurate costs.

Heat Pump Calculator​

Pentair has a Heat Pump Calculator to determine the appropriate size Heat Pump for your location. Pentair seems to do honest calculations based on the physics and efficiencies of each type of pump and energy source.

Raypak also has a Heat Pump Heater Sizing App.

To get the most accurate cost comparison you should change the default electric kwh, natural gas price, and propane price to actual prices in your area.
 

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In the interest of keeping all of our questions together, I will also share that despite spending MANY hours reading and trying to figure out whether a gas heater or HP is the best solution for us, I can't seem to do it. I am so frustrated but know that if I don't figure this out soon, I'll have another very short swim season.

Our pool gets full sun practically all day but it’s just too cold for me to enjoy outside of maybe mid-June through July. Even August starts getting cold for me. We don’t have a spa so what we’re looking for is to maintain the temperature a few degrees warmer than it would be naturally so that I can swim comfortably May-August, and September would be awesome. We aren’t ones to want to swim when it’s cold outside anyway so the limitations of a HP don't really concern me but we would love to be able to take advantage of all the warm (80+) days that we easily get in northern VA May-Sept.

I think a HP is the answer because we work from home and love to swim during the day when we have a little free time. We don't plan in advance and would love it if the pool was always warm. I'm sure we can't afford to keep it warm all the time with a gas heater, especially with gas prices rising, but I *think* we could with a HP. Our pool is 40K though, so I'm not sure if a heat pump is going to give us what we need.

I know this is a lot but I'd be grateful for any advice. Thank you.
 
Without a pool cover your pool can lose a few degrees of temperature on cold nights and then it may take half a day or more for the HP to bring the pool up to temperature.

Cold nights and when we get a cold spell will challenge a HP while a NG heater can bring the pool to temperature in a few hours.

I have a 35K pool with a 400K NG heater and no pool cover. My pool can lose 3 to 5 degrees at night and my heater goes on at 9AM and it is usually up to the 86F I like by noon.

If we get a cold or rainy spell I turn the heater off and then when warmer weather returns it usually takes a day of running for the gas heater to get the pool back up to temperature.
 
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Best case a 140K BTU heater will heat a 40,000 gallon pool 0.42 degrees per hour. That is best case at 80F and 80% humidity. As the temperature and humidity drop the HP output will decrease.

A 400K NG heater will heat a 40,000 gallon pool at 1 degree per hour in any temperature conditions.

You must use a solar pool cover to retain the heat a HP creates for it to be at all practical for you. If you don't use a pool cover then forget about a HP.

Raypak Gas Pool Heater Sizer​

Raypak has a Gas Pool Heater Sizer. It tells you the Temperature Rise/Hr and Natural Gas and Propane costs to heat a pool in your local area to selected temperature by month. Adjust the natural gas cost and propane cost in the lower left to your local gas prices for accurate costs.

Heat Pump Calculator​

Pentair has a Heat Pump Calculator to determine the appropriate size Heat Pump for your location. Pentair seems to do honest calculations based on the physics and efficiencies of each type of pump and energy source.

Raypak also has a Heat Pump Heater Sizing App.

To get the most accurate cost comparison you should change the default electric kwh, natural gas price, and propane price to actual prices in your area.
Thanks, I will try those calculators now. That's a bummer about the pool cover. We don't have an auto cover. We have thought about getting a solar cover but anticipate that it will be a real pain to put on and take off so we either won't do it, or won't swim so we don't have to deal with it. First world problems, I know. Maybe we need to rethink that.
 
Without a pool cover your pool can lose a few degrees of temperature on cold nights and then it may take half a day or more for the HP to bring the pool up to temperature.

Cold nights and when we get a cold spell will challenge a HP while a NG heater can bring the pool to temperature in a few hours.

I have a 35K pool with a 400K NG heater and no pool cover. My pool can lose 3 to 5 degrees at night and my heater goes on at 9AM and it is usually up to the 86F I like by noon.

If we get a cold or rainy spell I turn the heater off and then when warmer weather returns it usually takes a day of running for the gas heater to get the pool back up to temperature.
That's very helpful, thank you. Can I ask a stupid question? I understand that there will be evaporation and heat loss at night but will it generally be adequate to run a NG heater for a few hours in the am to get the pool back up to temperature (86 sounds like heaven) and expect it to maintain something close to that until night? Or should we expect that the heater is going to be running most of the day to maintain the temperature?
 
Your choices are:
  • HP + electric bill + Solar cover +pain of putting cover on and off
  • Gas heater + paying the NG bills
Your heater usage and gas bill will be high for a few weeks in June and late August into September. So maybe 8-10 weeks out of the year.
 
Your choices are:
  • HP + electric bill + Solar cover +pain of putting cover on and off
  • Gas heater + paying the NG bills
Your heater usage and gas bill will be high for a few weeks in June and late August into September. So maybe 8-10 weeks out of the year.
True! I think I keep hoping there's an option with electric bills + no solar cover + blissfully warm water constantly. :) I get that's not going to happen. I guess we need sleep on it and post pictures tomorrow. I really appreciate your help-- I have analyzed this forever to the point of doing nothing.
 
That's very helpful, thank you. Can I ask a stupid question? I understand that there will be evaporation and heat loss at night but will it generally be adequate to run a NG heater for a few hours in the am to get the pool back up to temperature (86 sounds like heaven) and expect it to maintain something close to that until night? Or should we expect that the heater is going to be running most of the day to maintain the temperature?

The variable is air temperature and pool exposure to the sun.

If the air temperature is in the 80's and you have full sun on the pool the heater is not going to run much to maintain 84-86F.

I find when the air temperature is more then 10 degrees below the water temperature I see the heater cycling often.

To manage your gas bill you need to manage the gas heater. You will learn how long it takes to heat up the pool. So get the heater going before you want to swim. Let the heater then maintain the temperature. Once you are done swimming for the day turn off the heater.

With a HP you pretty much need to leave the HP and your pool pump running 24/7 so that it generates what heat it can and maintains your pool temperature since it can take a while to get back up to temperature if you turn it off.
 
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I have a HP 140k (Pentair Ultratemp). My pool is a lot less volume than yours coming in around 16,000 gallons. First season with the pool, so only playing with the HP for the past few weeks. The other posters are spot on with the advice. So far I've learned to run it when temp is 60 to 85+ degrees. That is, 60 degree nights. I usually lose about 5 degrees over a 50 degree night (i dont run i over night) and if the day temp is below 80 nobody wants to get in the pool anyway. I keep the set point at 82 degrees which is colder than you want.

The weather this past weekend was that 60 to 85 degree sweet spot and today was a high of mid 90s. I had the HP on from last Thurday through Today (6 days). We don't plan to use pool until this weekend so it's going off until Friday.

My concern for you is a lack of performance with a 140K BTU HP for a 40,000 gallon pool. With conditions right I am getting 1 degree per hour and my pool is less than half the volume. Hope that helps, hit me up with any questions.
 
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I have a HP 140k (Pentair Ultratemp). My pool is a lot less volume than yours coming in around 16,000 gallons. First season with the pool, so only playing with the HP for the past few weeks. The other posters are spot on with the advice. So far I've learned to run it when temp is 60 to 85+ degrees. That is, 60 degree nights. I usually lose about 5 degrees over a 50 degree night (i dont run i over night) and if the day temp is below 80 nobody wants to get in the pool anyway. I keep the set point at 82 degrees which is colder than you want.

The weather this past weekend was that 60 to 85 degree sweet spot and today was a high of mid 90s. I had the HP on from last Thurday through Today (6 days). We don't plan to use pool until this weekend so it's going off until Friday.

My concern for you is a lack of performance with a 140K BTU HP for a 40,000 gallon pool. With conditions right I am getting 1 degree per hour and my pool is less than half the volume. Hope that helps, hit me up with any questions.
It does, thank you so much for sharing your experience!
 

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