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.

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.

Pentair MasterTemp

The Pentair MasterTemp series is a range of low NOx gas powered pool heaters with models from 175k to 400k BTU. There are models for both propane and natural gas including two “heavy duty” models for the latter.

To purchase a Pentair MasterTemp from Pool Supply World – Click Here.

Pentair MasterTemp Gas Pool HeaterDespite its functionality this pool heater is compact. It measures only 21″ x 21″ x 28″ (L x W x H) so is easy to install even where space is limited. A rotating digital display ensures that the controls are easy to see and use regardless of how the heater is positioned. The cabinet is a tough composite material which is not affected by heat or the weather.

However, the key selling points are:

  • It is certified for low NOx emissions so can be used where NOx emission restrictions are enforced.
  • It has an efficiency rating of 84% (using the standard copper heat exchanger) making it one of the cheapest to run gas heaters.
  • Heats up fast due to its fully pre-mixed system – which also contributes to its efficiency – so no waiting around for your pool to heat up.
  • Easy to operate – required temperatures can be set at the touch of a button and a digital display shows the water temperature, whilst five LEDs show you what is going on.

Pentair MasterTemp Brochure

There are also two “heavy duty” models which use a cupro-nickel heat exchanger. This stands up better to heavy use and poor pool chemistry but reduces the efficiency to 82%. ASME versions are also available for commercial use.

The Pentair MasterTemp heaters have a series of features designed to ensure safe operation but you can’t please everybody. For instance there is a factory set maximum water temperature which annoys some users (there are discussions online about how to get round this). However, overall this heater is a good choice if you need a low NOx gas heater.

Our recommended supplier is Pool Supply World who offer good prices which include shipping (often an expensive extra).

CLICK HERE to see their prices.

Other Pentair Pool Heaters.… pumps/mastertemp heater

Do You Really Need A Pool Heater?

I was reading an article recently about the pros and cons of installing a pool heater which made me think. On this site we are so busy looking at pool heaters and the issues surrounding them that it is easy to overlook the basic question –  do I really need a pool heater? Of course there is no easy answer to this as it depends on individual circumstances such as location and period of use required.

There is no doubt that a pool heater will allow you greater usage of your pool and therefore provide a better return on the large investment you have already made in the pool. It will also make using the pool more pleasant, even during the summer.

However against this there will be an additional cost of buying and running a pool heater (even a solar powered one) and additional maintenance work and cost if the pool is operational for longer. Only you can make that decision which is summed up nicely in that article:

Weigh the costs and benefits of having a heated pool before you buy one. Are you willing to spend a little extra time and money for a lot more fun? Think carefully – don’t just go diving off the deep end!

To read the full article Click Here.

Raypak Heat Pump

Raypak updated their range of heat pumps for 2019 but these are very difficult to find at present, most of the Raypak heat pumps on sale are from the 2018 range below.  The new range comprises six heat only models, two with heat/cool and one with power defrost. Click Here to see the product brochure.

The three smaller models range from 48-80k BTUH with a COP of 5.7-6.2 at 80/80/80. The remaining models are of the larger design with a BTUH up to 140k and a COP of 5.6-6.0. All feature:

    • Exclusive DuraSteel™ Powder-Coated Cabinet – They claim that a plastic cabinet is no match for the all steel Raypak cabinet.
    • Quiet Operation – Special fan design mean more air over the coil which translates to greater efficiency all while being whisper quiet!
    • Extremely Tough Composite Base – Rust proof and ultra sound deading base material keeps your heat pump up and running while holding sound levels to an absolute minimum.
    • Scroll Compressor – The unique design of a scroll compressor actually wears in over time, not out!
    • Spiral Titanium Tube – The spiral titanium tube heat exchanger provides a corrosion-free waterway that can withstand the abuses of harsh pool chemistry.
    • Seperate Pool/Spa Controls
    • Remote Compatible – The digital heat pump pool heater can be easily controlled by most two-wire and three-wire remote systems.
    • On Board Diagnostics – Tells you if there is a problem.
    • Built-in Mini Automation – Includes ability to work with solar and/or gas heater.

Previously Raypak offered four ranges of Heat Pump. These are still on sale so I have left the information from 2018 below:

The Compact Series – Three models outputting 50k, 66k & 83k BTU/hr (at 80F air & water and 80% RH) available with analogue or digital controls. The top model is also available with a Power Defrost option. This enables the heater to defrost itself whilst still heating the pool.

The Classic Series – Three models outputting 95k, 117k & 133k BTU/hr (at 80F air & raypakpool heaterswater and 80% RH) available with analogue or digital controls.

The Specialty Series – Eight models based on the two higher Classic models offering options like digital power defrost and cooling as well as heating. Three phase models are also available. Raypak say that this range is intended to offer features “not as commonly required”.

The Quiet Series – Raypak’s latest heat pump has been specially designed for quiet operation at only 59db.  There are three models outputting 95k, 117k, and 133k BTU/hr (at 80F air & water and 80% RH). These feature digital control and several extra features to ensure quiet operation such as a slow rotation fan motor and a custom engineered four blade fan.

In terms of features, the Compact series do not have sound installation pads on the compressor nor internal bypass valving in the heater exchanger but other than that the basic features are the same.

A heat pump may cost more than a gas heater to buy but they are extremely efficient devices which can be 3 to 4 times cheaper to run than natural gas and 6 to 7 times cheaper than propane. They are not as powerful, so cannot heat a pool as quickly, so are ideal if you heat your pool constantly.

All these heat pumps are built to Raypak’s usual high standard to give “rock solid performance at an affordable price”.  All versions feature a titanium heat exchanger, to withstand pool chemistry and corrosion and use a Spiral Rifled design to maximize the surface area.

The cabinet is a polyester coated rugged steel construction. There are large air coils (made by Raypak themselves) to maximize the heating capability at low temperatures.

The standard Raypak heat pumps run of a single phase power supply but will need their own circuit which will require an electrician but it should cost less than a gas heater to install.

Raypak Analog Control PanelYou can opt for digital or analog controls on the cheaper models. Both allow you to set a separate pool and spa temperature and are compatible with remote controls. The analog control has 6 LEDs which tell you what is going on whilst the digital control has on board diagnostics which can provide detailed information to the owner or pool technician.  The Raypak documentation indicates that the digital version is superior but, strangely, the prices are similar.Raypak Digital Control Panel

If you are looking for a low cost, environmentally friendly way to heat your pool a heat pump is ideal. A Raypak heat pump is a great choice as it combines the latest technology with Raypak’s reliability at an attractive price. It should give you years of hassle free use of your pool.


These heat pumps are not as widely available as many pool heaters featured on this site but Pool Supply World offer a limited range.

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.

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 our favorite suppliers including Pool Supply World.

Raypak Millivolt Pool Heater

The Raypak Millivolt heaters are versions of the Raypak Digital Heater for use where it is not possible or not practical to run an electricity supply to the heater. If at all possible it is best to use the Digital heater but if you need a millivolt heater look no further than this model from Raypak.

Click this link to order a  Raypak Millivolt heater from In The Swim.

The Millivolt pool heater is the same as the Raypak Digital Heater except for the ignition and control systems.

  • The ignition system comprises a constant pilot, sitting just below a small generator. The heat from the pilot flame generates a small amount of electricity measured in millivolts (thousands of a volt). This trickle of power is then used to operate the rest of the system.
  • The control system is a simple mechanical thermostat which you just set to the required temperature and forget.

This has the following disadvantages:

  • A small amount of gas is always being used.
  • Temperature control is not as accurate as in electronic models.
  • No operating/troubleshooting information is available as it is with electronic models.
  • The pilot can go out in windy conditions.
  • Not low NOx so cannot be used where this is a requirement.
  • Not allowed in some locations with natural gas.

However, apart from the above the Millivolt heater shares all the advantages of the Digital Heater such as:

The advanced design – the whole design of this gas swimming pool and spa heater, inside and outside, was engineered to stand the test of time.  Aside from the aesthetics of the heater’s design which compliments most of the latest pool designs, the original pagoda top design keeps the heater operational even in extreme weather conditions.

Weatherproof cabinet – The heater has a polyester coated, non-corrosive cabinet more durable than waterborne coated metal cabinets.  Beneath the hard and gorgeous exterior galvanized metal can be found which provides greater rust prevention and years of durable usage.Raypak Digital Heater

Polymer headers – Raypak’s state of the art engineering used 3-D computer designs to engineer the unit for optimum performance.  Polymer resin headers prevent rust from harming your pools surface giving you worry free swimming all year round.

Long Lasting – The burner tray is built to last for many years, from the stainless steel burners to the aluminized metal utilized in heat sensitive areas.  Should anything happen to the burners they can be quickly and easily serviced.  The ceramic fiber combustion box keeps the Raypak 2100 Millivolt heater efficiently running and keeps the outside jacket cool.  By utilizing space age materials the heater prevents build up of left over heat after being turned off.

With all these features, you may ask if whether or not the heater is fuel efficient.  The answer is yes at 82% they are much the same as other heaters at this price.

Considering purchasing a Raypak Millivolt heater? See the full range at In The Swim.

Other Raypak Pool Heaters.

Pentair Heat Pump

The Pentair UltraTemp Heat Pump is a high performance pool heater with the distinction of being the first pool heat pump charged with a non-ozone depleting refrigerant (R410A).

To purchase a Pentair Heat Pump from Pool Supply World – Click Here.

The UltraTemp heat pump range includes models ranging from 75 – 140k BTU/hr two of which feature the option to reverse the system to cool the pool. Heat pumps are environmentally friendly as they are very efficient, do not create any emissions and this one is even environmentally friendly at the end of its working life. To see the UltraTemp product brochure – Click Here.

Unusually you have a choice of color (Black or Almond) for the casing, which is a nice touch but not a major factor in deciding to buy one. Some of the features of this Pentair Heat Pump that are more interesting are:

  • Titanium heat exchanger to resist corrosion and ensure long life.Pentair UltraTemp Heat Pump
  • Scroll compressor which has fewer moving parts and increases efficiency and reliability.
  • Thermostatic expansion valve controls the refrigerant flow to maintain optimum efficiency over a wider temperature range.
  • Automatic defrost feature which allows the heat pump to operate at lower temperatures than would otherwise be the case.
  • Long life plastic cabinet which is resistant to corrosion, pool chemicals and the weather.
  • Easy to use LCD control panel so you know exactly what is going on.
  • Performance certified by AHRI (Air-Conditioning, Heating and Refrigeration Institute).
  • Very high efficiency – The COP (Coefficient of Performance) varies slightly but the base model has a rating of 5.8*.
  • Digital controls with dual thermostats offer precise temperature control for pool/spa combinations.

* This means that for the heat pump outputs 5.8 units of energy (heat) for every one unit (electricity) consumed. This is because it is not using the electricity to generate heat but to transfer it from the surrounding air to the pool water. The COP will vary depending on the air temperature and water temperature here it is based on 80 degrees for both.

Of course we have to accept that a heat pump costs considerably more than a gas heater (which would also be more powerful) and that the performance of a heat pump drops when the air temperature gets colder. However, unless you only heat your pool occasionally the low running costs and environmental credentials of a heat pump cannot be ignored.

If you are looking for a heat pump this Pentair Heat Pump has much to commend it. It is designed for reliability and long life and its key selling point is its high efficiency. It has a limited lifetime warranty on the heat exchanger and a 10 year warranty on the compressor. Reviews seem to be in the 4/5 star range.

Our recommended supplier is Pool Supply World who offer good prices which include shipping (which is an extra with many other suppliers) together with good service.

CLICK HERE to see their prices.

Other Pentair Pool Heaters.