Raypak Above Ground Pool Heater

The Raypak 106 and 156 are 105k and 150k BTU gas fired heaters for above ground pools. They are available for natural gas or propane but are not low NOx. Energy efficiency is 82%.

Apart from the power levels the only difference between the two models is the controls. The 106 has a simple analog control, you simply set the thermostat dial to the required temperature, whereas the 156 has digital controls. As well as providing an accurate temperature display this also incorporates on-board diagnostics and remote control capability.

To purchase a Raypak 105/156 from Poolsupplyworld – Click Here.

Raypak 106/156

Both models feature:

Cabinet with PolyTuf textured power coating – for years of durable service.

Wind-Resistant Design – protects it against the weather and falling leaves and other debris.

All-Copper-Fin-Tube Heat Exchanger –  allows maximum heat transfer to be attained and maintained. Also along with the polymer header and stainless steel tube sheets will ensure rust free waterways.

Automatic Bypass – automatically adjusts flow rates so works with a wide range of pumps, also helps reduce condensation caused by cold water.

Burner Tray – the stainless steel burner tray is built to last, self adjusts to any gas pressure fluctuations and is easy to remove for servicing.

Click Here to see the product brochure.

Raypak pool heaters are good quality and well liked by users. This above ground heater has a lot of good features so it is a pity that it has not been designed as low NOx. This will rule it out for many pool owners but if you don’t need a low NOx heater it is well worth considering.

These heaters are available through our favorite suppler Poolsupplyworld but at the time of writing (February 2018) we saw very good prices at PoolCenter.com.

Lochinvar EnergyRite Pool Heater

Lochinvar is a manufacturer of water heaters, boilers and pool heaters which was founded in 1946. They produce both commercial and residential pool heaters, the latter being the EnergyRite range.

The EnergyRite range comprises five low NOx gas heaters ranging from 150 – 400k BTU/hr. They are available for natural gas or propane (although the propane models are harder to find) and have a class leading efficiency of 88%. To see the product brochure Click Here.

LochinvarThe key selling points of these heaters are their fast heat-up time and their thermal efficiency. They also feature:

Built in floor shield – so you can locate the heater on any surface.

Easy venting options – so the heater can be located indoors or out.

Commercial grade heat exchanger – copper finned is standard but cupro nickel is an option.

Commercial grade cabinet and sealed combustion chamber – cabinet is long lasting and heater is windproof and keeps out wasps, spiders and other pests.

2 year warranty (3 years on heat exchanger).

lochinvar control


Service friendly control panel – provides easy temperature adjustment (separate settings for pool and spa) and troubleshooting in the event of any problems. It is also compatible with third party remote control systems.



Lochivar heaters have a good reputation and this is a quality heater with a high efficiency. It is however a bit more expensive than similar heaters, such as the Hayward H Series. If you feel that these heaters are worth the price there are available from several of our favorite suppliers including Pool Supply World and Specialty Pool Products.

Sta-Rite Max-E-Therm

Sta-Rite was founded in 1934 and sold a range of water related products. It was acquired by Pentair in 2004 and although the Sta-Rite brand was retained their pool heaters became part of the Pentair range. The Max-E-Therm is now discontinued but is still widely available.

The Max-E-Therm is a powerful low NOx gas pool heater available in 200, 333 and 400 BTU models. There are versions for natural gas and propane and heavy duty models which feature a cupro-nickel heat exchanger instead of the standard copper version.  The standard versions have an energy efficiency of 84% and the heavy duty versions (for low pH, high flow or heavy use) an efficiency of 82%.

To purchase a Max-E-Therm heater from Pool Supply World – Click Here

MaxethermThe obvious difference between the Max-E-Therm and most other pool heaters is its design. It is described in the brochure as having “sleek contempory styling”. Personally I struggle with that but I suppose how it performs is more important.

The casing is made from “Dura-Glas”, a material exclusive to Sta-Rite, which provides protection against the elements. Rust proofing is completed by a plastic manifold and PVC union connections.

Features include an LED temperature readout with dual thermostat controls (for pool and spa), temperature safety lockout and six position control panel mounted on the top. This can be rotated 360 degrees for easy viewing. Self diagnostics are provided which can pinpoint any problems.

The heater is designed for fast heat-ups so it will quickly get on with the job of heating your pool. To view the product brochure – Click Here

This heater has been on the market for quite some time so there is quite a lot of user feedback. This is mostly posative including many 5 star reviews. In general once it was installed and working users were happy, negative comments included a number which complained about units which were damaged when delivered. This reinforces our advice to buy from a reputable supplier used to dealing which these large and heavy products.

We recommend Pool Supply World – to visit their website please Click Here.

Pentair MasterTemp 125

The MasterTemp 125 is Pentair’s low NOx gas pool heater for smaller installations, including above-ground pools, spas and in-ground pools up to 15,000 gallons. Their aim is to deliver the sort of energy efficiency and advanced operating features that were previously available only on larger, more expensive, models.

There are just two versions, one for natural gas and one for propane. To purchase a Pentair MasterTemp 125 from Pool Supply World – Click Here

mastertemp125As its name suggests the heater is rated at 125 BTU and is 82% efficient. This level of efficiency is possible due to its “pre-mixed combustion technology” which also enables fast heat-up. The heater weighs only 80lbs which together with its compact size makes it easy to install where required. It requires a 3/4″ gas line and a standard electricity supply. Plumbing connections are 1-1/2″.

Click Here to see the product brochure.

The heater features a digital display/controller which rotates if required to provide easy access for programming and monitoring.mastertemp125display

Price wise it is slightly more expensive than the MiniMax model it replaces but it is more powerful and has more features.

Heaters aimed at this market have not generally had rave reviews and it is therefore interesting that Pentair have chosen to market this as the baby brother of their successful MasterTemp model range. Hopefully this means that they are confident that it will be reliable.

Even though this heater has been available fora few years now, there are not a great many user reviews out there. Hopefully this means that most buyers are happy with it, we will have to wait a bit longer to find out.

This model is readily available including from our recommended supplier – Pool Supply World. Click Here to visit their site.

AquaCal TropiCal Heat Pumps

The TropiCal range are AquaCal’s economy range of heat pumps. They are aimed at owners of above-ground pools or small in-ground pools. For 2017 a new look was introduced but the specifications remained unchanged.

Compared to the HeatWave SuperQuiet range they are less powerful, smaller, lighter, a bit noisier and have a lower throughput. There is only a single thermostat but they are significantly less expensive.

To buy an AcquCal TropiCal heat pump from Poolcenter – Click Here.

There are five 60Hz models outputting 51k, 72k, 96k, 112k and 132k BTU with a COP ranging from 5.4 up to 6.0. Click here to see the product brochure.

(There are also five 50Hz models which are less powerful.)TropiCal Heat Pump

All the models feature:

  • Lockable, flip-out control panel protected against weather
  • Microprocessor controlled automatic defrost which allows operation down to the mid to lower 40s fahrenheit
  • Impact resistant rust proof cabinet
  • R410A environmentally friendly refrigerant
  • Variable warranty on other parts depending on where you live – details here

However the patented ThermoLink heat exchanger is only fitted on the top models. The basic versions have a Tube in Tube heat exchanger.

If you are looking to heat a small pool the TropiCal may be ideal for you. It is designed to give optimum heat output in a small footprint whilst having a long operating life and being resistant to wear and tear. Yes it is an economy model, and doesn’t have all the advanced features you find in the HeatWave SuperQuiet range, but that is reflected in the price making it good value for money.

To see prices at Poolcenter – Click Here





AquaCal HeatWave SuperQuiet Heat Pumps

AquaCal have been producing heat pumps since 1981 and the HeatWave SuperQuiet range is a series of  powerful heat pumps aimed at the residential market and smaller sized commercial pools and spas. As the name suggests their unique selling point is that they are designed to be quiet in operation. For 2017 they revised the model range and changed the cabinet design but there have been no changes since.

Click Here to see the range at Pool Supply World.

There are three standard 60 hz models SQ125, SQ145 and SQ225 plus two “Icebreaker” models SQ120R and SQ166R.

  • At  80/80/80 (Water Temperature/Air Temperature/Humidity) these range between 101 – 143k BTU and offer a COP of between 5.5 and 6.8.
  • The “Icebreaker” models feature cooling as well as heating and will operate at temperates down to the mid twenties Farenheit.

(there are also 50hz versions available which are slightly less powerful)

Click Here to see the product brochure.

The above all operate on a single phase supply and all but the SQ125 can also support a three phase supply.

The other unusual feature of these heat pumps is the titanium heat exchanger with the titanium tubing having a lifetime guarantee. The warranty on these heaters is good but the period that the compressor is covered depends on where you live – Click Here for more information.

Key Features;

  • Titanium Heat Exchanger – failure of the heat exchanger is a common cause of heat pump failures. Unlike more common cupronickel units the heat exchangers on these AquaCal heat pumps are not affected by the pool water chemistry and carry a limited lifetime warranty.
  • Scroll Compressor – unique fan blade and scroll compressor technology means ultra quiet operation. It should also ensure reliability and durability.
  • Digital Controls – easy to use controls feature large display and water resistant keypad. The units also feature dual thermostats to control pool and spa separately.  There are also on-board diagnostics and a microprocessor controlled defrost cycle. The keypad can be locked to prevent any tampering with the settings.
  • Corrosion Proof Cabinet – cabinet is rust proof, fade proof and crack resistant.
  • Off-Set Plumbing – which makes for easy installation.
  • Environmentally Friendly – uses green R410A refrigerant.
  • Operates At low Temperatures – operates at lower temperatues than other heat pumps.

AquaCal claim to be the largest manufacturer of heat pumps in the world so they obviously know what they are doing. Looking online there are surprisingly few reviews of these pool heat pumps but those that there are, are mostly positive and all seem to agree that these units are quiet with several noting that the pool pump makes more noise.

CLICK HERE to see the range at Pool Supply World (at the time of writing – April 2019 Poolcenter had a few of these heat pumps on sale at a significant discount click here for details).

How Do I Choose Between Manufacturers?

Having decided on the type of pool heater you want you are still faced with choosing between many different models from the major manufacturers. You might ask – which is the best model? However there is no easy answer to this.

In many ways it is like looking at models of cars from different manufacturers and trying to chose between them. There are pluses and minuses for all of them but they will all get you from A To B and once you get used to any of them you will probably be quite happy. So you end up buying where you can get the best deal.

With pool heaters you are likely to be quite happy with any of the models from the major manufacturers although you might want to consider the following:

Price – are you looking for the best pool heater regardless of price or does “best” mean a good value for money compromise. For example there are some highly energy efficient gas heaters available but they are very expensive (see why) so a cheaper, less efficient, heater may be better value.

Efficiency – the energy efficiency of pool heaters varies and is usually related to price i.e. the higher the energy efficiency the higher the price.

Emissions – For gas heaters low NOx emissions are a requirement in some locations which rules out some of the cheaper heaters.

Salt – Some heaters can be used with salt chlorinated pools but others are recommended for freshwater pools only.

Location – Some pool heaters can be used at altitude without any problem whilst others require modification to work above a certain height. Some put more emphasis in their design on handling the elements so are more suitable for exposed locations.

Connectivity – Some heaters offer reversible connections which can make all the difference if the heater has to be installed in a difficult space. Indeed in this case the actual size and shape of the heater might be a factor.

Cooling – If you are buying a heat pump you will need to decide whether you want the option of switching it to cooling in hot weather.

Having considered the above factors you should have been able to narrow down your list of possible heaters to buy. You should then look at what deals are available taking into account the price, any delivery charge and the warranty offered.

Are Pool Heaters Safe?

We have no hesitation is saying that a pool heater purchased from one of the major manufacturers and correctly installed and maintained is 100% safe.

Of course like any heating appliance they can be dangerous if mistreated. Gas heaters produce carbon monoxide so if installed indoors they must be properly vented and when installed outdoors proper thought must be given to the positioning (under house windows is not a good site). Adequate ventilation is essential so it is important to ensure that debris does not build-up around an outdoor heater. They must also be kept clear inside so an annual service by a qualified gas engineer is strongly advised.

Modern gas pool heaters feature a variety of safety features including ignition safeguards, pressure regulators, water pressure relief valves and automatic shut off controls all of which means that in use they are very safe.

Electric heat pumps offer little in the way of danger other than that they are electrical devices and must be respected as such but essentially electric shock hazard is avoided by construction and installation of the heater in accordance with strict electrical standards and codes.

Solar systems are also safe if properly designed and installed. It is quite practical to buy a system and install it yourself without creating any problems.

To ensure ongoing safe operation all pool heaters should be drained over winter to prevent any frost damage.

Many people consider making their own DIY pool heaters, usually solar systems and it is here that safety can be a question mark. All sorts of safety issues can arise such as pumping very hot water into the pool when first turned on.

In summary pool heaters are a safe way to increase the value you get from your pool but need to be properly installed and maintained. Only build you own pool heater if you are confident that you know what you are doing.


How To Minimize Energy Usage

Having got your pool heater up and running you should follow the tips below to minimize energy usage. Avoid bad habits developing which waste energy and hence push up your heating bills.

  • Use a pool cover whenever the pool is not in use. A good cover can reduce heat loss by over 50% because it vastly reduces evaporation. This also means you will need less pool chemicals and the cover will also keep debris out of the pool.
  • Do all you can to protect your pool from the wind. Even a gentle breeze at 5mph can lower the pool temperature significantly (again the big enemy is evaporation) so money spent on landscaping can be a great investment.
  • Keep a thermometer in your pool. This will easily enable you to see how the pool feels at a given temperature and you will be able to discover the lowest comfortable temperature for the water.
  • Set the pool heater thermostat for this lowest comfortable temperature. Heating the water any more will be throwing away money. It is a good idea to mark the thermostat dial at your desired setting or stick a reminder near an electronic control to try and prevent any accidental over heating.
  • If the pool is not going to be used for a few days turn the heater down to 70 degrees. For any longer of period a gas heater should be turned off as it will be more cost effective to let the pool temperature drop and heat it back up later. A heat pump is more suited to continuous heating but if you are going away for a couple of weeks you should still turn it off.
  • If possible return the warmed water in at the bottom of the pool rather than at the surface. This will heat the pool more effectively and efficiently.
  • Make sure that your heater is properly maintained and serviced as recommended by the manufacturer.  Also make sure that it is kept free of debris at all times.

What About Combining Types Of Pool Heaters?

If you want to get the maximum use of your pool but minimize the heating costs you might look at using more than one type of heater.

Perhaps the most obvious option here would be to have a solar heating system backed up by a gas heater or heat pump. This would mean that you could take advantage of free solar power when it is available but still have a means of heating the pool when the weather is poor, early morning/late evening and outside the summer months.

As well as keeping heating costs as low as possible this would also be an environmentally friendly option but of course it has the disadvantage of being considerably more costly to set-up so is not a viable option for many people. However it is worthwhile looking at you much energy you could generate using a solar heating system to see if it makes financial sense. Have a look at this site to see how you might do that.