Balancing and heater warranty

[HappyAuer]

I'm a new first-time pool owner with a newly-installed AGP and a natural gas pool heater (Raypak 266). I have a TF100 test kit and plan to use TFPC methods to balance my water. The heater manual gives chemistry guidelines as conditions of the warranty. I'm concerned about how restrictive they are. The ones that apply to my pool are in the right column on the page below:

I raised my tap water pH from 7.2 to 7.5 by aerating with the garden hose while filling the pool. I still need to add some Borax to get to at least 7.6.

FC can't exceed 5, so I need to take care to keep CYA low; I'm going to aim for 40 and try to keep it there so that my target FC level will be 5 or less. I will probably use trichlor once or twice each year to go on vacation-- rarely for more than a week. I expect to offset the CYA in the trichlor by normal backwashing of my sand filter and by lowering the water level each winter. The bullet point about occasional shocking is vague, so I constructed a bypass to take the heater out of the loop when raising to shock level.

What surprises me is the CH requirement of 200-400. Mine is currently 100, so I'll need to raise it. I would have thought that low CH would be best for a heater, to minimize scale on the heat exchanger.

I'm keeping a log of all my test results and chemical additions. Am I taking the right steps to keep my pool water clean while also protecting my heater and its warranty? Is deliberately raising CH good for the heater, and if so, why?

 

[JohnN]

I have no experience with heaters or their warranties, so I can't help you. I do wonder, though, how do they know what levels you keep everything at? Are you required to keep a log of your chemical levels or something? If they only check your water when you have a warranty claim, I would think you could go with TFP recommendations, and then if you have a warranty claim, before they come out you could get your water to their "ideal" levels. Like I said, I have no experience with heaters or warranties, so this is all just speculation.

 

[HappyAuer]

Great question, John. There's no mention of a formalized procedure where they test my water. I am keeping a log, but how would they know it's accurate? I tend to agree with you, and I plan to favor TFPC over the heater manual guidelines.

 

[JasonLion]

Warranty service varies wildly in how strictly the enforce the rules. There are times when they will require documented weekly water test results from a pool store before honoring a claim, and there are other times when they will just fix it without asking. I hear about examples of both extremes fairly regularly. Some of these requirements seem to be there simply so they can avoid honoring the warranty claim if they want to. Others, like the PH range, really do make a large difference to the lifetime of the heater.

 

[HappyAuer]

Thanks, JasonLion.

Some of these requirements seem to be there simply so they can avoid honoring the warranty claim if they want to.

That's exactly what I'm afraid of.

My priorities, in order, are:

1. Have clean water
2. Preserve my pool and equipment
3. Comply with warranty requirements.

I think I can accomplish all 3 by keeping CYA at or below 40. But I'm curious whether higher FC levels are bad just because they might void the warranty, or are they really damaging to the heater?

Suppose for example that my CYA was 100. PoolMath would give me a FC target of 8 - 13. If I maintained FC around 10 for a season, would that cause more wear on the heater than keeping CYA near 40 and FC around 5?

 

[jblizzle]

That would be no more wear as the active chlorine level would be the same. You have to look at the FC to CYA ratio.

A pool with FC of 5ppm and no CYA is WAY harsher than anything we would recommend even at shock level. In fact 2ppm FC with no CYA is worse too. They do not understand the relationship with CYA.

The pH is really the only parameter that could have a large impact on the equipment, I think.

 

[JasonLion]

Low PH and calcium scaling inside the heater are the two main problems. Low PH is much more common, but calcium scaling can cause serious problems in some situations.

 

[HappyAuer]

jblizzle, you've confirmed what I suspected: that the active chlorine level is the important factor in prolonging the life of the heater. It's a shame the manufacturer doesn't see it that way, but at least I can be confident that I won't ruin my heater by following PoolMath recommendations for FC.

JasonLion, the CH level concerns me. Does it really make sense for me to raise my CH from 100 to 200? I guess the rationale would be that at 100, my water may be "aggressive". But I would have thought scale would be a far bigger concern for a heater. Is 200 still a pretty safe level to avoid scale?

 

[JasonLion]

CH at 200 is very safe. In a plaster pool the recommended level is 250 to 350 and even a little higher than that is no big deal. Just keep in mind that the only reason to add calcium is the warranty, and even if you do add calcium there is no guarantee they will honor the warranty (should the issue ever come up).

 

[HappyAuer]

Thanks, JasonLion. It sounds like the only real downsides to raising CH to 200 will be the cost and effort of adding a substantial amount of calcium chloride. I think it's probably worth it in order to improve my chances of getting warranty coverage if I need it.