heat exchanger scaling

[mmeyer]

I have a Raypak 406. The spa jets have been spewing black chunks. I took the header of the furnace it was full of thin black scales. I used a shop vac and removed the scaling and replace the broken thermostat. Everything works fine now but I'm concerned the heat exchanger must be damaged. Do I need to replace my heater?

 

[ajw22]

Please put your location in your profile so it shows
<--- here
Knowing your location can make a difference in our advice.

If your heater is working I would say you are fine for a while. No reason to replace a heater that works.

I think you should look at why your heat exchanger scaled as if you don't change things it will likely return.

How do you maintain your water chemistry? What test kit do you use? Post your test results from your own test kit in the form:

FC
CC
pH
TA
CH
CYA
Water temperature

@ps0303 @Pool Clown @swamprat69

 

[mmeyer]

I'm in the Pacific Northwest. I use the heater only for the spa and it's about 10 years old. I keep the pool setting in normal range but I don't have it in front of me. My pH and FC tend to both run higher. CYA is always normal, water temp in winter is 50F.
The scaling I see is not white, but black and hard. It's nonmagnetic and doesn't rust. It's been getting worse over the last year. It looks like it might be from the liner from the heat exchanger tubes. I guess I'm worried the next step is leaking of the heat exchanger if I'm right. On the other hand, I feel stupid replacing the heater if everything is working...
Thanks for taking the time to resond!
PS I'll edit my profile

 

[ajw22]

Deterioration of the heat exchanger comes from poor water chemistry or high flow rates. I suspect water chemistry but can't comment without specific numbers.

Good luck.

 

[mmeyer]

No doubt you're right. I'm just curious if I've diagnosed the scaling correctly and instituting the correct remedy.
It's my first pool and I'm sure I made mistakes along the way. I'll aim for better water health.

 

[ajw22]

I'll aim for better water health.

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