- Jul 21, 2013
- 65,360
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
We don't see scale in the heater often. Once you get it running we can discuss your water chemistry.
www.troublefreepool.com
@swamprat69
That's basically the procedure.
You just have to circulate descaling solution through the exchanger until the scale is gone.
Many people use muriatic acid, but it's aggressive to copper.
They sell various descaling solutions that might be safer for copper.
Do some research to find a solution you think will work for you. Almost anything effective on scale will probably etch copper to some degree.
You need to remove the thermal regulator so that it doesn't block the exit of the exchanger during the process.
Only do the process for the minimum amount of time to reduce the risk to the copper.
The exchanger is likely compromised already.
If it's not leaking now, it might soon.
Periodically, remove one of the bottom manifold bolts to see if water is collecting in the combustion chamber.
If you want a less aggressive chemistry towards copper I would suggest either using CLR or Lime-Away. CLR is a mix of gluconic and lactic acid while Lime-Away is sulfamic acid. Both of those products are fairly aggressive towards calcium carbonate but not to copper. Muriatic acid is only really aggressive towards copper oxide but not copper metal. Without an oxidant present (such as chlorine or dissolved oxygen or peroxide), muriatic acid will only very slowly dissolve copper. If you chose to use MA, then use it for the least amount of time needed and then neutralize the interior with a mix of water and baking soda or washing soda. Once the heat exchanger heats the copper metal back up, it will repassivate with an oxide layer.
Cleaning vinegar (6% acetic acid) will dissolve calcium scale too but at a slower rate than the others.
Pentair Mastertemp 250 Service Heater Issues
Hello all. Newbie here hoping to find some assistance. I have a Pentair Mastertemp 250 pool heater. When the heater is turned on, after a variable amount of time the service heater light comes on. It is almost always within the first 10 minutes of operation. Once the service heater light comes...

@swamprat69
That's basically the procedure.
You just have to circulate descaling solution through the exchanger until the scale is gone.
Many people use muriatic acid, but it's aggressive to copper.
They sell various descaling solutions that might be safer for copper.
Do some research to find a solution you think will work for you. Almost anything effective on scale will probably etch copper to some degree.
You need to remove the thermal regulator so that it doesn't block the exit of the exchanger during the process.
Only do the process for the minimum amount of time to reduce the risk to the copper.
The exchanger is likely compromised already.
If it's not leaking now, it might soon.
Periodically, remove one of the bottom manifold bolts to see if water is collecting in the combustion chamber.
If you want a less aggressive chemistry towards copper I would suggest either using CLR or Lime-Away. CLR is a mix of gluconic and lactic acid while Lime-Away is sulfamic acid. Both of those products are fairly aggressive towards calcium carbonate but not to copper. Muriatic acid is only really aggressive towards copper oxide but not copper metal. Without an oxidant present (such as chlorine or dissolved oxygen or peroxide), muriatic acid will only very slowly dissolve copper. If you chose to use MA, then use it for the least amount of time needed and then neutralize the interior with a mix of water and baking soda or washing soda. Once the heat exchanger heats the copper metal back up, it will repassivate with an oxide layer.
Cleaning vinegar (6% acetic acid) will dissolve calcium scale too but at a slower rate than the others.
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