Heater element corrosion every year

[gmg]

Three year old spa, Balboa guts, salt water with Saltron mini, pH balanced. I typically close it for a few months each winter (drain, blow out jets w compressed air, antifreeze, turn off breakers.) On reopening the spa, both this year and last I found extensive corrosion at the heater terminals which trips the GFCI and required replacement of the heater. 

I maintain chemistry while in use and I'm careful to hold the bulkhead nut when tightening the terminal wires. What might be causing this much corrosion in such a short time, especially when the spa is unused over the winter? 

[RDspaguy]

And why is it rust colored when there is no iron in the element and only stainless in the tube?

I would typically blame your water chemistry, but perhaps the salt cell is playing a part. 

Maybe our chemical guru guy can help. @waterbear, got any ideas?

[Cusser]

Are the big nuts brass or just were brass coated?

[RDspaguy]

Brass. In 26 years of this I have never seen so much rust coming from a heater leak. 

Is there a rust stain at the heater returns (jets)?

[waterbear]

couple of things that I see (doesn't mean I'm right, just an educated guess):

 

10 hours ago, RDspaguy said:

perhaps the salt cell is playing a part. 

WE HAVE A WINNER!

It's an add on salt system and the heater is probably not 'salt-safe" which really requires titanium coils and not incoloy.

10 hours ago, RDspaguy said:

And why is it rust colored when there is no iron in the element and only stainless in the tube?

it's rust colored because stainless steel is made from iron and some stainless steel does rust, particularly when salt is present. My guess is that the screws are not salt grade stainless either. 304 stainless is the most common type but salt will cause corrosion. 316 stainless is more impervious to salt. IF the heating element is incoloy then there IS iron in the heating element! It is a nickel-iron-chromium alloy.

 

 

 

[gmg]

Very knowledgeable people here; I appreciate the information.

There must be thousands of Balboa systems out there running salt water, and I've never seen any "not suitable for salt systems" warning. To have two brand new heaters both rust out in a year without a visible water leak seems crazy and I don't want to replace the heater each year. How can I prevent this from happening again, other than losing the salt system?

[waterbear]

You are using an aftermarket salt system and not a factory installed one.

Same problem happens with swimming pool salt systems. The heater and other parts needs to be made of salt resistant materials, which cost more. Even screws used to hold light rings/skimmers/and such, light niches, ladders, etc. need to be made of salt resistant materials! Often a sacrificial a sacrificial zinc anode is installed in swimming pools to help prevent corrosion  Not sure if sacrificial anodes are used in salt spas. @RDspaguy, @CanadianSpaTech care to chime in?

https://aquamagazine.com/features/protect-your-pool-from-saltwater.html

If you had a factory installed system then salt resistant materials  would be included with the tub and you would pay more for the setup in addition to the cost of the salt system.  I would see which  heater is OK for a salt system and use it in your tub if you can. Once again @RDspaguy, @CanadianSpaTech your input would be appreciated.

I do know that many spa manufacturers state that if you use an aftermarket salt system the warranty is voided, reason being that the components used in the spa are NOT salt rated.

[waterbear]

56 minutes ago, gmg said:

There must be thousands of Balboa systems out there running salt water

To the best of my knowledge Balboa does not make a control pack with a salt system. They do make ozone systems. They are not the only manufacturer of spa control systems and parts.

[RDspaguy]

I have never seen an anode in a portable spa. I have seen them on inground spas and pools. Those were not saltwater, though. I thought it was a part of a bonding system to give a direct water bond somewhere other than the heater and light niche, which can both suffer from "tracking" (aka electrolysis) that can damage the metal parts over time.

One had a copper part as well, with a dc power source, and was supposed to (according to the owner) keep the water sanitized. Everything had a blue/green layer, even parts above the waterline, and it smelled terrible.

 

[waterbear]

10 hours ago, RDspaguy said:

One had a copper part as well, with a dc power source, and was supposed to (according to the owner) keep the water sanitized.

Copper ionizer.  Useless snake oil, IMHO. Just a way of getting copper ions into the water. Copper is an effective algaecide and a lousy sanitizer, not even as effective as silver.

[waterbear]

10 hours ago, RDspaguy said:

and it smelled terrible.

the smell of unsanitized water perhaps.

[RDspaguy]

Not sure. It was a sort of earthy smell as I recall. That was a long time ago.

[waterbear]

2 hours ago, RDspaguy said:

Not sure. It was a sort of earthy smell as I recall.

Yep, unsanitized water.

[dashmer]

Going back to the problem of salt corroding the heater, is there sufficient salt buildup in 3-4 months of using the dichlor then bleach method to cause problems with an incoloy heater?

[waterbear]

no.

[gmg]

I haven't heard back from Balboa but two of their retailers told me that there should be no problem using this particular heater in salt water, for what that's worth. But if they weren't salt-compatible we'd be seeing lots of reports like this, and I don't.

And I still think there has to be something more to it: two heaters each corroding out in less than a year? What are the odds of two defective heaters in a row?

It's easy enough to install a sacrificial anode. I'll also remove the heater during the off season to insure it stays completely dry. Any any other suggestions you guys come up with. 

Thanks for the information.

 

[Dracogt]

On 5/18/2021 at 8:41 PM, gmg said:

I haven't heard back from Balboa but two of their retailers told me that there should be no problem using this particular heater in salt water, for what that's worth. But if they weren't salt-compatible we'd be seeing lots of reports like this, and I don't.

And I still think there has to be something more to it: two heaters each corroding out in less than a year? What are the odds of two defective heaters in a row?

It's easy enough to install a sacrificial anode. I'll also remove the heater during the off season to insure it stays completely dry. Any any other suggestions you guys come up with. 

Thanks for the information.

 

Hey, so I stumbled upon this thread and was curious about how to add this "Sacrificial Anode" I've seen mentioned, though further googling seems to mostly show it added to pool heaters. I have the same Balboa heater that you posted and will be replacing my heating element for a second time as  Can you or someone else share how to add this Anode? Sounds like a zinc nut needs to be added somewhere?

Thanks!

[PlymouthMark]

I have this problem on my 2013 Island/Artesian Spa with balboa heater. When we moved here in 2019 we started using a saltron mini. From that point every spring the heater was dead with either the circuit breaker tripped or the message “heater is too hot”. Five times the repair guy takes out the heater and shows me corrosion on the terminals inside. He replaces the heater and I am good for another year. (The heater is usually on warranty and labor costs $120.)  I think I am finally going to give up and start using chlorine. 

[CanadianSpaTech]

20 hours ago, PlymouthMark said:

The heater is usually on warranty

What how who... How is this under warranty? If your tech is replacing the element under warranty he/she either likes you a lot and/or is an idiot. Clearly a water quality issue. He/she is also likely using a low grade general service element and should be using a higher quality element like a mid range Teflon or top end Titanium element especially if using a Saltron mini. JMO