Pentair UltraTemp Heat Pump
The Pentair UltraTemp is a Heat Pump with models having 70,000 to 140,000 BTUs of heating capacity based on 80F air temperature, 80% relative humidity, and 80F water inlet temperature. Note that Heat Pump BTU output and efficiency vary with air temperature and relative humidity, as shown in the table below:
Some models include a chiller capability.
The Pentair UltraTemp integrates with Pentair Automation Systems through an RS-485 data communication cable. When connected by the data connection, the automation can raise an IntelliFlo pump speed when the UltraTemp is on and lower the pump speed when the UltraTemp is turned off.
Pentair gives a ten-year warranty on compressor parts and labor, plus a lifetime warranty on the titanium heat exchanger. Check the Pentair website for warranty details.[1]
2025-2026 Pentair HEATERS & HEAT PUMPS Catalog
Pentair HEATERS & HEAT PUMPS PARTS Product Catalog 2025-2026
MasterTemp Gas Heater versus UltraTemp Heat Pump
UltraTemp Heat Pumps and MasterTemp Gas Heaters are very different technologies.[2]
Heat pump technology is the most efficient way to heat a pool. However, the lower BTU rating of heat pumps means it can take longer to heat the pool to a desired temperature. Heat pumps also have reduced heating performance when the ambient air temperature is very low (when the ambient temperature drops below about 50F). This is because heat pumps do not make heat; they capture the free heat from the air and move it into the water. Heat pumps are typically sized from 70,000 BTU to 140,000 BTU.
Gas heaters work well in all ambient air temperatures and have higher BTU output (commonly up to 400,000 BTU). They are great if you want to heat water quickly in all weather conditions, but they are much less energy efficient than a heat pump.
The US Dept of Energy has some good, unbiased articles about choosing the right kind of pool heating equipment for your needs - Swimming Pool Heating
Here’s a blog article from pool equipment retailer In The Swim that sums it up fairly well, especially the comparison table and the two lists of “best choice” points, located about halfway down the page - Pool Heaters: Heat Pumps vs. Gas Pool Heaters | InTheSwim Pool Blog
Heat Pump Operation
Heat pumps operate by taking heat from the surrounding air and transferring it into the water. The warmer the air and the more humidity in the air, the more latent heat is available for heating your pool. With a properly sized heat pump for your pool, the heat pump should raise your pool on average 1° F per hour depending on air temperature, humidity, and water temperature. The ideal or rated condition for the heat pump is 80° F air temperature, 80% relative humidity, and 80° F water temperature. As conditions decrease from 80/80/80, the heat pump performance will decrease slightly.[3]
Heat Pumps are best utilized to maintain a set water temperature; they are not intended to provide instant or fast heating. It is unreasonable to expect a heat pump to perform like a gas heater with a much higher BTU output and faster response. Additionally, gas heaters are not dependent on environmental conditions. Swimming pool heat pumps are very similar to home heating and air conditioning heat pumps and should be treated similarly.
Proper operation and use of the heat pump are to set it at your desired temperature and leave it. Like your home HVAC unit, your heat pump will turn on and off automatically to maintain the desired temperature. Operate your heat pump during the day's heat to take advantage of the sun's energy unless your night electrical cost is significantly lower than daytime.
Your heat pump will still operate when the temperature drops at night, but the output will decrease. It is acceptable to shut the heat pump off and not use it for extended periods of time. When you need to heat your pool, please plan accordingly since, depending on your pool temperature and environmental conditions, it may take the heat pump days to heat your pool back to your desired temperature.
It is important to note that an UltraTemp® Heat Pump will not heat a pool as fast as a large gas or electric pool heater. If the pool water is allowed to cool significantly, it may take several days to return to the desired swimming temperature.
For weekend use, it is more economical to maintain the water temperature at or near the desired temperature. For extended non-use, turn the heat pump completely off or decrease the temperature setting of the control by several degrees to minimize energy consumption.
Installation Notes
The Pentair Installation manual[4] recommends the UltraTemp pad be placed at the same level or slightly higher than the filter system equipment pad.
It also recommends placing the heat pump on a flat, slightly pitched surface for proper drainage of condensation and rain water.
Avoid lawn sprinklers near the heater. Note that the wind may blow water from sprinklers towards the heater. Any water blowing on the heater from a sprinkler system can cause mineral buildup on the evaporator coils and electronics. Salt water can also be an issue if the heater is located near the coast. Keep all plants and shrubs trimmed and away from the heat pump.
The heat pump will not heat above 104°F or cool below 45°F (40°C - 7.2°C)
To maintain maximum performance and efficiency, keep the air coil clean from dirt and debris. It is recommended that you clean your air coil once a year by flushing it with compressed air or hosing it off with a garden hose. Do not use a pressure cleaner on the heat pump.
UltraTemp Power Requirements
All models require 230V AC power and a 50A circuit breaker.
Pentair Heat Pump Calculator
Pentair has a Heat Pump Calculator to determine the appropriate size Heat Pump for your location.
Automation Control
The UltraTemp Heat Pump can be controlled by Pentair Automation Systems: IntelliCenter, IntelliTouch, and Easy Touch.
When you connect the UltraTemp to Pentair automation using the RS-485 data connection, you need to add a solar temperature sensor in addition to the air and water temperature sensors.[5] The solar temperature sensor can be left loose in the load center. The automation system does not use temperature readings. It just looks for resistance.
A 10K resistor will work and is less expensive. Or you can install a temperature sensor.
You can steal the air temperature sensor and connect it to the solar sensor screws to test it immediately until you get a resistor.
When connected using the RS-485 data connection, the automation can increase pump speed when the UltraTemp is on.
Remote connection via the RS-485 connector is only available on IntelliTouch and EasyTouch software version 1.11 or higher or the IntelliCenter. All other automation systems must connect using the Relay Remote “Spade” terminals.
IntelliConnect does not support controlling the UltraTemp using the RS-485 data connection. You must use the Relay Remote “Spade” terminals on the UltraTemp connected with a 2 wire cable to the heater connection terminal on the IntelliConnect.
EasyTouch Firmware 2.19 fixed problems communicating with the UltraTemp Heat Pump.[6]
For the IntelliCenter, the heat pump needs to be configured as UltraTemp, not Heat Pump, and the control screen should look like...
Under automation RS-485 remote control the UltraTemp display will show the * heart beat in the upper right...
Heater Bypass
Pentair requires a Heater Bypass when your circulation pump is over 2 HP or if the total flow exceeds 120 gpm (456 LPM). Even if not required, a heater bypass is good to have so you can remove your heater from the water loop and continue running the pool should it require maintenance.
Multple Heaters
The Pentair heat pump may be used with a gas or electric heater or any combination of heat sources, including solar. All heat sources must be plumbed in series to work correctly and efficiently.
Multiple heat pumps can be installed in parallel, with each heat pump receiving an equal flow of water. Confirm that your plumbing system can provide a minimum flow of 30 gpm (110 pm) to each heat pump.
UltraTemp and MasterTemp Heaters Together
You can have a Pentair MasterTemp gas heater and a UltraTemp Heat Pump on a pool. They are plumbed in line and hooked up to the IntelliCenter via RS-485 cable. In the programming, you can choose heaters for your spa and/or pool.
The IntelliCenter offers four modes of operation:[7]
- Off: No heat.
- Heater: If heat is needed, only the gas heater will engage.
- UltraTemp Preferred: If heat is needed and the heat pump can handle it, the heat pump will engage. Otherwise, the heater will engage.
- UltraTemp Only: If heat is needed, only the heat pump will engage.
In UltraTemp Preferred mode the IntelliCenter will prioritize the heat pump over the gas heater but it will not do dual-mode or boost-mode switching that the ETi Hybrid heater will do.
The IntelliCenter can regulate temperature via the heat pump 1st - if it can not maintain temp it reverts to the gas heater. But after that it does not go back to the heat pump to maintain. You have to switch it manually.[8]
UltraTemp Chiller Mode
When in chiller mode Pentair forgot to link the temperature differential up to the chiller portion. So if you have a chiller set point of 87 degrees, and your temperature bounces back and forth between 88 and 87 degrees - your fan will cycle on/off, on/off, on/off until the temperature is a constant 87 degrees. That will eventually burn the fan motor up.[9]
That problem is planned to be addressed and corrected in IntelliCenter firmware V1.046. The diff temp buttons will be replaced with +/- buttons in the Ultra-Temp setup screen.[10]
UltraTemp ETI Hybrid Heater
The UltraTemp ETI heater combines a heat pump and gas heater. It has four selectable modes: Heat Pump only, Gas only, Hybrid, Dual. In “Dual” mode the heater runs both the heat pump and gas heater simultaneously for maximum heat output. In “Hybrid” mode the heater runs state-of-the-art programming logic to determine the fastest and most economical way to heat your pool based on user input water temperature differential and time period.
Dual mode switching allows both heaters to be engaged to seek the setpoint. The boost mode will come into play when the delta between the incoming water and the setpoint are outside of a set temperature. This means that when you turn on your spa for instance it can start heating with the gas heater to get it within range then use the heat pump to finish it off and keep it there.[11]
Unfortunately, econo-mode attempts to heat the body for 1-6 hours with the heat pump and if it cannot reach temperature it will kick in the gas heater to bring it up to the setpoint.
Unfortunately as one member in Colorado learned, this heater is not meant to be installed in any climate where freezing temperatures may occur, even if running the heater in gas-only mode.[12]
The UltraTemp ETI Hybrid heater always produces condensate whenever the gas heater is running (regardless of water temperature) so there also will always be water in the condensate drain line; due to the length and routing of that line with the condensation management system it will freeze.
If the UltraTemp ETI heater is to be used in temperature below freezing then electric heat tape should be put around the condensate drain so it does not freeze. Raising the heater 12" can facilitate an easier gravity fed condensate drain.[13]
UltraTemp Runs but Does Not Generate Heat
We have seen two instances of burnt wires that connect to the contactors in Pentair UltraTemp Heat Pumps. The HP fan will run but the compressor does not run to generate heat.
If the contactor wiring looks good then check the Start/Run capacitor.
See Heater Issue and Pentair UltraTemp 120 H/C Compressor Issue.
The contactor is HartlandControls CON-3/24/40, HCCY3XQ04CG999, 3P 24V 40A Contactor however the root cause of the failure is probably elsewhere in the heat pump.
Repairs
Parts diagrams including replacement part numbers are at HEATERS & HEAT PUMPS PARTS Product Catalog 2021
Replacing UltraTemp Temperature Sensor
See Thermistor replacement thread.
- ↑ https://www.pentair.com/en/knowledge-base/pool-spa-equipment/warranty.html
- ↑ https://www.troublefreepool.com/threads/intellicenter-and-mastertemp-400-communication.209684/post-2073090
- ↑ https://www.pentair.com/content/dam/extranet/aquatics/residential-pool/owners-manuals/heaters/ultratemp/ultratemp-heat-pump-installation-and-users-guide-en-fr-sp.pdf
- ↑ https://www.pentair.com/content/dam/extranet/aquatics/residential-pool/owners-manuals/heaters/ultratemp/ultratemp-heat-pump-installation-and-users-guide-en-fr-sp.pdf
- ↑ https://www.troublefreepool.com/threads/intellicenter-quick-reference-information-guide.198056/post-1777329
- ↑ https://www.troublefreepool.com/threads/easytouch-screenlogic-heat-pump-comm-issues.235133/post-2201142
- ↑ https://www.troublefreepool.com/threads/pentair-ultratemp-preferred-setting.269756/post-2364425
- ↑ https://www.troublefreepool.com/threads/gas-heater-heat-pump-chiller.193934/post-1724624
- ↑ https://www.troublefreepool.com/threads/gas-heater-heat-pump-chiller.193934/post-1724624
- ↑ https://www.troublefreepool.com/threads/glacier-pool-coolers-vs-heat-pump-chiller-help-me-decide.208566/post-1834786
- ↑ https://www.troublefreepool.com/threads/looking-for-heat-pump-pool-heater-for-40k-gallon-pool.246323/post-2158323
- ↑ https://www.troublefreepool.com/threads/pentair-eti-hybrid-first-winter-season.220714/post-1932558
- ↑ https://www.troublefreepool.com/threads/ultratemp-eti-hybrid-heater.287990/post-2529168
