Pentair UltraTemp Heat Pump - Further Reading

Pentair UltraTemp Heat Pump

The Pentair UltraTemp is a Heat Pump with models having 70,000 to 140,000 BTUs of heating capacity. Some models include a chiller capability.

The Pentair UltraTemp integrates with Pentair Automation Systems though a 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 lifetime warranty on the titanium heat exchanger. Check the Pentair website for warranty details.[1]

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 that it can take longer to heat the pool to a desired temperature. Heat pumps also have reduced heating performance when the ambient air temps are very low (when ambient temp drops below about 50F.) This is because heat pumps do not make heat; they simply 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 temps, and they have higher BTU output (commonly up to 400,000 BTU.) Gas heaters are great if you want to heat water up quickly in all weather conditions, but a gas heater is much less 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 not reasonable to expect a heat pump to perform like a gas heater which has 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 therefore should be treated similarly.

Proper operation and use of the heat pump is to set it at your desired temperature and leave it. Your heat pump will turn on and off automatically to maintain your desired temperature much like your home HVAC unit. To take advantage of the sun’s energy, operate your heat pump during the heat of the day.

Your heat pump will still operate when the temperature drops at night, but the output will be decreased. It is acceptable to shut the heat pump off and not use it for extended periods of time. When you have a need to heat your pool, please plan accordingly since it may take the heat pump days to heat your pool back to your desired temperature, depending on your pool temperature and environmental conditions.

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 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 the heat pump be placed on a flat slightly pitched surface for proper drainage of condensation and rain water.

Avoid any lawn sprinklers near the heater. Note the wind may blow water from sprinklers towards the heater. Any water blowing on the heater from a sprinkler system can cause mineral build up on the evaporator coils and electronics. Salt water can also be an issue if 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 to clean your air coil once a year by flushing the coil with compressed air or hosing off the coil with a garden hose. Do not use a pressure cleaner on the heat pump.

UltraTemp Power Requirements

All models require 230V AC power and except for the 70,000 BTUs, which requires a 40A circuit breaker, other models require 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, 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] Solar temperature sensor could be left loose in load center. The automation system does not use the temperature reading but just looks for resistance.

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 have to use the Relay Remote “Spade” terminals on the UltraTemp connected with a 2 wire cable to the heater connection terminal on the IntelliConnect.

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 take your heater out of the water loop and continue running the pool should the heater require maintenance.

Multple Heaters

The Pentair heat pump may be used in conjunction 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 getting an equal flow of water. Confirm that your plumbing system can provide the minimum flow of 30 gpm (110 lpm) to each heat pump.

UltraTemp and MasterTemp Heaters Together

You can have both 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 have a choice of heaters for your spa and/or pool.

The automation is supposed to 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.[6]

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.[7]

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.[8]

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.

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.[9]

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.

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.

Pentair UltraTemp Burnt Contactor1.jpg
Pentair UltraTemp Burnt Contactor2.jpg