Intellicenter heating past the temperature set point.

JamesW

TFP Expert
Mar 2, 2011
24,159
Heaters should never heat above the set point.

If you have a hot tub set to 104, is it ok to heat to 107?
 

ajw22

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This article describes how thermostats manage heater short cycling through temperature differential and cycles per hour.


The article illustrates how a thermostat can heat 1 to 1.5 degrees above set point if it is set to have a temperature differential of 3 degrees.

We don't know the algorithm Pentair uses for their temperature cycling. But no heater keeps the temperature exactly to the set point. The water temperature varies a bit above and below the set point.

A hot tub set to 104 may get to 105.5 if a 3 degree temperature differential is used.
 

JamesW

TFP Expert
Mar 2, 2011
24,159
The heat pump is being controlled by a 2 wire remote. It should stop heating when the remote switch is open. The remote switch opens at the set point.

The temperature has to be certain amount below the set point to turn on, but a heater should never continue to heat past the set point.

Show one pool heat pump that says that it will continue to heat past the set point.
 

JamesW

TFP Expert
Mar 2, 2011
24,159
The heat pump doesn't even know what the set point is. So, it has nothing to do with the decision to heat or not heat. It's not going to ignore the open fireman's switch and just keep running.

The system is not going to tell the heat pump to keep running past the set point.

The differential to start might be 1 or 2 degrees, but that's always below the set point.
 

Stoopalini

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There is something about the way Pentair coded their automation, which makes the solar temp sensor required for operation with a heat pump.

Here is the note included in AquaCal's installation instructions, for my SQ150VS heat pump, describing the requirement when connecting to EasyTouch or IntelliCenter.

It must be something within their code base, where the logic is looking for a resistance across that terminal; as the reading doesn't matter, only that there is not infinite resistance. Which is why a simple 10kOhm resistor works.

1616684711562.png

For my AquaCal heatpump, it can connect VIA a 2-wire fireman's switch, or VIA RS-485 SmartBus. But the SmartBus connection also only uses 2 wires, being the two data wires. The power and ground wires of the RS-485 bus are not used.

So I wonder if Hawk is connected to the SmartBus (using only 2 wires) instead of a fireman's switch connection point? This would explain how the heater can heat past the set point, since the set point would come from the controller and not the heater directly.

1616684842486.png

This would explain how the heater can heat past the set point, if the set point in the heater itself is disabled when being controlled in this way.
 

JamesW

TFP Expert
Mar 2, 2011
24,159
If the heater is set up as a gas heater, then the system does not know that there is a heat pump.

A heat pump can be configured to run like solar where it will require the solar temperature to work. In the case of a missing sensor, the heater should default to off and not work at all.

If the heat pump is not set up as solar, the solar should be disabled and the sensor should not matter.

If there is some reason that the solar sensor is required for a heat pump, a missing sensor should keep the heater from running. In no case should it make the heater continue to run indefinitely.

For example, if a gas heater does not receive a water temperature reading from the thermistor, the heater defaults to off. It doesn't just turn on and begin running continuously.

If a heater runs past a set point, something is wrong and needs to be fixed.
 

hawkmoon7

Member
Nov 27, 2020
23
Florida
Hi everyone. I'm sorry for all the confusion and I appreciate all of your guidance. Now that everything has been working correctly for weeks, I decided to remove the solar temp sensor. (I was adding an actuator, and was in the panel anyway, so I gave it a go to see what would happen). Nothing in the setup or heater was changed at all, and the pool was set to 88 as it's been for awhile. I let it run for the day, and the pool got to 92 before I manually turned it off. I have since added the "solar sensor" back, and it is again working correctly.

I can't say if a different configuration would avoid the requirement for the solar sensor, but in my case, it did remedy the problem. And I simply used a resistor in lieu of the sensor, so it cost me nothing to add.

My setup is as follows:

Thermeau: <Pool Mode> is set to off, <Spa Mode> is set to 104. A wire connects into the remote switch terminal on the Thermeau that switches from <Pool Mode> (off) to <Spa Mode> (max temp).

The other end of that wire is connected to the "Gas Heater" terminal in the Intellicenter. When heating is required (as determined by the Intellicenter sensors and settings), it activates the "Gas Heater" relay and the Thermeau then activates it's <Spa Mode> (max) and when the Intellicenter reaches the set temperature, it disables the "Gas Heater" relay and the Thermeau switches to <Pool Mode> (off).

With this arrangement, it only seems to work if it gets a reading from the solar sensor that is anything other than "Error". (It's default when no sensor is attached).
 

hawkmoon7

Member
Nov 27, 2020
23
Florida
I'll also add that the Intellicenter displayed the heating icon (a red flame) the whole time. Even though the set temp had been passed. So the Intellicenter "intended" to keep the remote heater on. It isn't like the heater wasn't getting the message or operating independently of the Intellicenter. If I manually turned the heating off in the Intellicenter, the Thermeau responded correctly and stopped heating.
 

mknauss

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Have you sent this information to Pentair? I would suggest bundling up what you have done and sending it to them via their website contact system.
 
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panic_button

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Show one pool heat pump that says that it will continue to heat past the set point.
JamesW-

FWIW, I spent 2 hours with Pentair UltraTemp support yesterday. I was told several times that the UltraTemp has a 2° Delta for the desired temperature.
 

JamesW

TFP Expert
Mar 2, 2011
24,159
JamesW-

FWIW, I spent 2 hours with Pentair UltraTemp support yesterday. I was told several times that the UltraTemp has a 2° Delta for the desired temperature.
The heat pump is not deciding whether or not to heat.

So, the delta should not matter.

In any case, the delta should be below the set point and never above.

Also, it's going way past 2 degrees difference.

If a heater heats past the set point, it's a problem that needs to be fixed.

1 degree might be acceptable. Anything more is unacceptable.
 

revitup

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Maybe Hayward is different but my HP differential setting will allow heating above the set point by design. I have it set at 6 degrees and the pool will heat above the set point 3 degrees, shut off and reenergize at 3 below the set point, more or less.
 

panic_button

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One of my biggest complaints, it should hit the desired temperature and shut off, not run for hours more costing additional electricity dollars. Granted it is only $1- $2 more each day, but over 30 days it adds up.
 

JamesW

TFP Expert
Mar 2, 2011
24,159
pool will heat above the set point 3 degrees,
That's just ridiculous.

The set point is the set point.

What's the point of having a set point if the heater is just going to do whatever it wants?

So, now you have to play games and try to trick the heater into doing what you want by choosing a set point 3 degrees below what you really want.
 
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revitup

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Set at 90. Shut off today at 92.8 pool temp.
 
Last edited:

JamesW

TFP Expert
Mar 2, 2011
24,159
Set at 90. Shut off today at 92.8 pool temp.
I guess I don't see why the heater continues to run for hours when the set point is reached.

Are you adjusting the set point to make it turn off where you want?

Can't you adjust the differential?
 

revitup

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I guess I don't see why the heater continues to run for hours when the set point is reached.

Are you adjusting the set point to make it turn off where you want?

Can't you adjust the differential?
I do adjust to set point so it reaches the max that I want. The differential is adjustable between 3 and 9 degrees though I haven’t tried it higher than 6.
 

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