Cause of gasket failure

[plannersteve]

This morning I found my tub nearly empty.  Investigated and found a leaking connection to the spa heater.  When I disassembled, the gasket between heater and tail piece on the piping had cracked.  I attached a picture of the gaskets I removed.  It appears that the gasket material is failing.  I've read other posts where the material on gaskets is residue from oils and it appears some of the material on these gaskets might be that.  But the gasket material is clearly eroded and softened as well.

I replaced them both, but my bigger concern is all the other harder to replace gaskets that might be on their way to failure.

I use the dichlor then bleach method.  Starting point is around 110 ppm Ca Hardness and 80 TA.  50 ppm Borate as well.  pH is kept around 7.5 with frequent testing.  Use MPS shock every 10 days or so.  Hot tub gets daily use by one person, me.  The tub water gets replaced 3 times per year.  The hot tub (Nordic Retreat MS) is closing in on 6 years in operation.

Is there something I need to consider with tub chemistry to prevent this?  Or should I be using some spa flush method to remove the residue?  Could that residue weaken the gasket material?

Thanks, Steve   

 

[waterbear]

Gaskets wear out and do need to be replaced periodically. Constant contact with hot water and oxidizing sanitizers will takes its toll.

[plannersteve]

On 7/7/2023 at 7:33 PM, waterbear said:

Gaskets wear out and do need to be replaced periodically. Constant contact with hot water and oxidizing sanitizers will takes its toll.

Thanks for the reply.  I hope it is that simple.  

[waterbear]

12 minutes ago, plannersteve said:

I hope it is that simple.  

Occam's razor is a principle  that says that if you have two competing ideas to explain the same phenomenon, you should prefer the simpler...

In other words KISS.

[RDspaguy]

Chemical damage is the #1 cause of gasket failure. Pressure gaskets are the first to show signs, with the heater gaskets being the quickest of all, likely from the heat. You do have many other gaskets, and they are all damaged to some degree, but those not under pressure (jet flange gaskets) can last much longer.