Heater whining
- Thread starter doncaruana
- Start date
I will drive out to the store again tomorrow and get a new one from them. Although I may insist we test it before I leave (45 minutes one way). It will take a week via mail order. And, yes, this is a genuine pentair part.
- Jul 21, 2013
- 65,342
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
You should also check the exhaust gas temperature during operation.
Excessive temperatures indicate low water flow.
The new models use the Menu to get the SFS.
Here is what the normal exhaust temperature should be:
www.troublefreepool.com
Excessive temperatures indicate low water flow.
Exhaust Gas Temperature.
While running, press and hold the On button to display the exhaust temperature (Older Models).The new models use the Menu to get the SFS.
Here is what the normal exhaust temperature should be:
- Below 250 degrees...very low
- 250 to 290 ..................low
- 290 to 350.................acceptable
- 350 to 480 ..................high
- Above 480...................error/shutdown.
Pentair MasterTemp Heaters - Further Reading
www.troublefreepool.com
It seems inconsistent.
Maybe it is sticking sometimes.
Maybe try to reinstall it and see if the noise goes away.
Check the stack flue temperature during operation.
Maybe it is sticking sometimes.
Maybe try to reinstall it and see if the noise goes away.
Check the stack flue temperature during operation.
Actually I had hit the "Hold" on that, so ignore that last post. It opens at 130 degrees - I did some more detailed testing. This is a Taylor thermometer so I'm kinda assuming it's accurate. I pulled it out and let it close and then put it back in at 124 degrees and it will not open again. So I guess the question is how accurate is my thermometer. But the behavior does seem to indicate and issue with the regulator based on what you guys have told me. I'll go buy another thermometer tonight and try that too.
- Jul 21, 2013
- 65,342
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
I don't think the thermal regulator is a precision device that will be closed at 119F and open precisely at 120F. +/- 10% is probably acceptable if it opens and closes repeatably.
Do we know how hot the water coming through the heater is? Should 130 really be enough? How long can I run it without the thermal regulator? I'm still stuck on no noise without it. Maybe my heater isn't getting the water all the way to 130?
- Jul 21, 2013
- 65,342
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
The water will barely get past 120F.
Heater Outlet Temperature Rise
Heater outlet temperature rise will depend on the water flow rate. Slower water flow will have greater outlet temperature since the same BTUs go into less water volume.Changing the pump speed can vary the return temperature from just warm at high RPM to very hot at minimum flow for the heater.
For example, a 400,000 btu/hr heater with an efficiency of 84% transfers 336,000 btu per hour to the water.
At a minimum required flow of 40 gpm, there will be 2,400 gallons of water (20,000 lbs.) that receives the heat.
Each btu raises the temperature of one pound of water by one degree Fahrenheit.
336,000 btu into 20,000 pounds of water is 16.8 degrees of temperature rise (336,000/20,000).
So, the maximum temperature rise you should ever have is 16.8 degrees Fahrenheit.
As shown below, higher flow results in a lower temperature rise.
- 40 gpm = 16.8 degrees temperature rise
- 50 gpm = 13.44 degrees temperature rise
- 60 gpm = 11.2 degrees temperature rise
- 70 gpm = 9.6 degrees.
- 80 gpm = 8.4 degrees.
On all pool heaters there are temperature limit switches, the first one is usually set to trip (turn the heater off) if the water temperature, in the manifold and leaving the heater, is in the 125 - 130 degree F range (that's coffee-hot). The second is usually set to between 135 - 140 degree F range (that's hot-coffee-hot). This is dependent on the manufacturer of the heater. You really don't want either of those temperature waters hitting you directly.
Not all the water going into the heater actually goes through the heat exchanger, there is always an internal bypass that allow just the right amount to go through and then mix back with the cooler bypassed pool water and enter the pool or spa. What this does is produce a temperature rise each time the water passes through the heater. On many gas heaters it will be about 15 degrees. A 15-degree temperature difference is what you are calling luke-warm, it doesn't feel like much, but that is how it is supposed to feel at first. The heater just keeps adding that much more heat to the body of water until it reaches the set point.
So, when the spa first starts heating in the winter, the water goes into the heater at maybe 45 degrees and comes out at 60, that would feel warmer, but just barely. By the time the water hits 100 (the starting temp most people like in a spa) it would come out at 115, that's where we start feeling really hot water coming from the heater (approaching coffee-hot) and don't always like sitting close to a jet.
By law, a pool heater can't be set to heat above 104. That means the maximum outlet temperature entering the spa could be about 119 just before the heater turned off as the spa water reaches the setpoint. That's usually uncomfortable to sit right at the jet, and close to tripping one of the hi-limits in the system.
If it does not open at 120 degrees, I would replace it.
The only reason that the thermal regulator is used is to prevent condensation from forming on the heat exchanger and dripping into the combustion chamber, which can cause corrosion.
This mostly happens when the water is cold and the humidity is high.
It needs to be 100% open at 120 degrees.
Not all of the water goes through the heat exchanger, so the water in the heat exchanger should stay over 120 while the heater is running.
A lot of water goes through the internal bypass during heating.
When not heating, the thermal regulator blocks water from exiting the heat exchanger and all water goes through the internal bypass.
Try running with the thermal regulator in and then out and check the stack flue temperature to see if they are the same or different.
The only reason that the thermal regulator is used is to prevent condensation from forming on the heat exchanger and dripping into the combustion chamber, which can cause corrosion.
This mostly happens when the water is cold and the humidity is high.
It needs to be 100% open at 120 degrees.
Not all of the water goes through the heat exchanger, so the water in the heat exchanger should stay over 120 while the heater is running.
A lot of water goes through the internal bypass during heating.
When not heating, the thermal regulator blocks water from exiting the heat exchanger and all water goes through the internal bypass.
Try running with the thermal regulator in and then out and check the stack flue temperature to see if they are the same or different.
Most likely, the regulator is partially opening creating a tiny gap that produces a whistle as the water goes through the gap.
- Jul 21, 2013
- 65,342
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
BTW, the heater High Limit Switch will shutdown the heater if the outlet water temperature exceeds 135°F (±8°F).
Ok so not opening at 120 is an issue. Bought another thermometer to double check that.
As far as the flue temp, how would I check that?
As far as the flue temp, how would I check that?
While running, press and hold the On button to display the exhaust temperature (Older Models).
The new models use the Menu to get the SFS.
The new models use the Menu to get the SFS.
Oh yeah. You mentioned that. I have an older model with a newer control board. So I'm not sure which will work. Lol.
- Jul 21, 2013
- 65,342
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Would it be okay to run it for a couple of hours without the regulator then? Water temp will probably be 65 by the morning and air temp about the same.