Need advice on repair/replacement of Pentair MasterTemp

[jkusmier]

My Pentair MasterTemp 400 is in its 7th full season of use and has been leaking water for a few weeks. I finally removed one of the access panels and sure enough, the bottom of the combustion chamber/"tub" is heavily rusted. I have a salt pool, and while I maintain my salt level around 3600 and pH between 7.4-7.8, I guess time took its toll on the copper heat exchanger long ago, and the leak finally ate out my combustion chamber as well. It probably didn't help that my builder didn't install a bypass valve, so flow was constant and eroded the heat exchanger even when the heater wasn't in use. Quick questions:

I have a 17,500 Gal inground pool. After checking the specs on a 250 BTU unit, I think that will suffice. The 400 BTU was probably overkill on a pool my size - thoughts?

I plan to buy an HD model with a cupro-nickel heat exchanger. It appears that regardless of BTU rating, models equipped with a cupro-nickel heat exchanger cost $300+ more than those with copper heat exchangers. I've read it's well worth the investment, especially with a salt pool. Thoughts?

Finally, and what should probably be my first question: would it be more cost-effective to replace the heater, or to just have the unit serviced and the heat exchanger and combustion chamber replaced? Dumb question since I haven't asked for a bid, much less called for service, but wholesale prices on the heat exchanger and combustion chamber total $750+, and I'm sure the additional labor for repair versus installing a replacement unit will add another $200-300.

I appreciate any advice, and thanks,
Joe

 

[JamesW]

The heater size depends on several factors. If you want on-demand heating on short notice, then a larger heater would be a better choice. If you plan to keep the pool heated, and don't need a fast temperature rise, then the 250 would probably be a better choice.

I would recommend a cupro-nickel exchanger.

I would recommend replacing the entire unit vs. an expensive repair.

Pentair MasterTemp HD Low NOx Pool Heater - Electronic Ignition - Cupro Nickel - Natural Gas - 250,000 BTU HD - 460806

 

[jkusmier]

Well, the replacement heater arrived last week. The box was pristine but when my installer and I removed the heater we discovered cracks on the outer panels. When we removed one of the access panels we discovered some a broken bracket and some internal parts that were hanging loose. I ordered the heater from Amazon, and quickly checked the reviews (which I'd ignored previously because I was already well familiar with the MasterTemp) and read reports of similar damage. I promptly reported the damage and happily, Amazon is offering a full refund, no restocking fee or return shipping charges. Apparently my complaint was the straw that broke the camel's back, because within a day Amazon marked the heater listed with the particular Amazon merchant/store I'd ordered from with "Item Under Review" while they investigate whether the problem is due to shipping practices, quality control, etc. According to some of the reviews, Pentair redesigned the MasterTemp heaters sometime in the past year or two, using thinner plastic throughout and replacing internal metal brackets with plastic ones. I contacted a few pool retailers and was told they too experienced similar problems until they started strapping and shipping the heaters on pallets. (Mine did not ship on a pallet). UPS will be picking the old heater up this week, and I ordered a new one from another online seller (a Google Trusted retailer). I called the seller on two different days, spoke with different persons and both confirmed problems last year but stated none this year after shipping the heaters on pallets. They suspect the boxes were being turned upside down, which is somewhat more difficult to do if they're strapped to a pallet. So we shall see. Curious, has anyone out there experienced a similar problem or heard about this?

Thanks,
Joe