MasterTemp 400 Propane Heat Exchanger failure

Jump to latest Follow Reply
V

Vitiro

Member
May 10, 2021
8
Arizona
I own an Airbnb in Scottsdale and I heat the pool frequently as it is used constantly. I purchased all new Pentair gear in November 2020, so the three-year warranty has expired on everything five months ago. This weekend, I noticed that the pool was not heating, and upon inspection by my pool guy, the heat exchanger has failed and is leaking water out of the back.

My pool guy stated that this could be caused by poor quality water chemicals, and this has happened a few times over the years when the water was not holding chlorine, and we needed to drain the pool. I have a separate company that does weekly pool chemicals, but according to the reports they send me, the water is in good shape.

I have called Pentair to see if they will extend the warranty for five months and give me a service call, which is pending a supervisor calling me back.

My pool guy said this repair is $2,000 or more, and it's usually better to just buy a new heater, which costs $3,600. Since I would just be buying one piece of equipment this time, I will just get a one-year warranty, which is worrisome as I am not 100% confident this will not happen again.

Are there options for commercial pool heating that are in the same price range as the MasterTemp 400, and is that something I should consider?

Other tips or is the best suggestion just pay the $3600?
 
I do not have any pics of the leak, asked him to send me some.

I have an inground SPA connected to the pool. I installed the propane heater first and then added the heat pump. I use propane heater when its super cold or to heat spa to 102 degrees.

Screenshot 2024-03-18 111129.png
 
Is that tablet chlorinator used?

How do you chlorinate the pool?

Tablets have acid that will leak back into the heater when the pump is off and destroy the copper heat exchanger.

You should get rid of the tablets and install a SWG.

Show us better pics of the equipment as I do not see a check valve between the tablet chlorinator and the heater output. Even though they don;t really protect the heater and eventually leak.
 
  • Like
Reactions: JamesW
The tablets are the likely cause of the heat exchanger failure.

Trichlor creates a nasty, corrosive stew of low pH and high chlorine water that eats copper very quickly.

Even a single time when there are tabs in a feeder while there is no flow can destroy a heater.

Does the heater have a bypass?

Remove the manifold and show the copper tubes.
 
Yes I am using the chlorinator, it just takes Tablets and pool guys refill every week.

I turn off the pump 4 hours per day so its running most of the time. I just turn it off during peak energy time. I guess i could run pump 24/7?

Switching to a SWG is another expense that really do not want to do at this time - i could look into that. This is already going to be expensive.

Yes I have a check valve, I can get a picture of that later.

Is a Check Valve the same thing as a bypass. Yes between chlorinator and Heater there is a valve and when they installed it told me it makes it so water does not go back into heater.
 
Last edited:
What are all chemistry readings?

Maybe the check valve has failed and allowed the water from the chlorinator to get to the heat exchanger?

If you have tabs in a feeder, the pump should never be off.
 
Pick your poison.

Run your pump 24/7 and pay for more electricity.

Even with running your pup 24/7 the tablet acid can damage your heater. It will just take longer.

Plan to replace your heater every few years if you continue the way you are now.

The economics of a SWG is not that more when you consider that you are buying chlorine for the next 5 years or so. And it will give a much better pool experience for your guests.
 
  • Like
Reactions: JamesW
Vitiro said:
Since I would just be buying one piece of equipment this time, I will just get a one-year warranty, which is worrisome as I am not 100% confident this will not happen again.
Click to expand...
Heaters = 2 Years.

www.pentair.com

Pool Product Warranty Information

Whether you are planning a pool party for friends and family or prefer the serene sensation of a calm pool, Pentair has the pool and spa solutions just for you.
www.pentair.com www.pentair.com
 
Geeze, yeah nobody ever told me that I should run my pump 24/7. Yes I guess it is possible that valve has failed, will need to check that.

Here is current readings from last week.

READINGS
5 ppm free chlorine
5 ppm total chlorine
7.6 pH
120 ppm total alkalinity
 

Enjoying this content?

Support TFP with a donation.

Give Support
Vitiro said:
Yes I am using the chlorinator, it just takes Tablets and pool guys refill every week.

I turn off the pump 4 hours per day so its running most of the time. I just turn it off during peak energy time. I guess i could run pump 24/7?

Switching to a SWG is another expense that really do not want to do at this time - i could look into that. This is already going to be expensive.

Yes I have a check valve, I can get a picture of that later.

Is a Check Valve the same thing as a bypass. Yes between chlorinator and Heater there is a valve and when they installed it told me it makes it so water does not go back into heater.
Click to expand...
Tab feeder destroyed the heater, especially a MasterTemp with the low plumbing (Max-E-Therm is the same.
Check valve ALWAYS fails, even the ones designed for that Rainbow chlorinator. They cannot stand up to the corrosive "soup" that flows backward when the system is off. If you are determined to use it, never turn the pump off.
I won't install a heater with one of those in the system, in-line or off-line.
 
My pool guy texted me back saying SWG are not great in Arizona as it gets so hot in the summer, you will still need to use Chlorine 3 or 4 months per year. Will not really change my monthly pool service cost.


So would it be suggested to just do chlorine bobber in the pool and not the Tab Feeder?
 
Vitiro said:
My pool guy texted me back saying SWG are not great in Arizona as it gets so hot in the summer, you will still need to use Chlorine 3 or 4 months per year. Will not really change my monthly pool service cost.


So would it be suggested to just do chlorine bobber in the pool and not the Tab Feeder?
Click to expand...
Floater is better than a feeder. Ask the many Arizonans on this forum if you could get them to give up their SWG.
 
How big is your pool? Unless it is extremely large, a 60k SWG cell should be able to keep up even in the summer.

We had a brutally hot summer last year and I never had to set my SWG higher than 45% (with the pump running up to 20 hours/day).

SWGs aren't cheap, but the lifecycle economics are very favorable compared with other chlorination methods (some pool services will give you a substantial discount if you have a SWG since it dramatically reduces chemical costs). If you can call it a business expense - even better :D.
 
Last edited:
Vitiro said:
My pool guy texted me back saying SWG are not great in Arizona as it gets so hot in the summer, you will still need to use Chlorine 3 or 4 months per year.
Click to expand...
Just not true.

How big is your pool?

What speed do you run the pump?
Vitiro said:
I just turn it off during peak energy time.
Click to expand...
How much is peak energy cost?

You can probably use 200 watts at all times except for heating.

Just set the pump rpm high enough to get 40 GPM during call for heat.

If the pump is on, the tab juice cannot migrate backwards into the heater.
 
Last edited:
1poolman1 said:
Ask the many Arizonans on this forum if you could get them to give up their SWG.
Click to expand...

You can pry my SWG from my cold dead hands … I’d rather fill my pool in with dirt then not have an SWG …

To the OP - your pool service company is lying to you. They just want to manage the pool the way they want to and an SWG doesn’t fit into their pool service model. I would go so far as to say their mismanagement of the pool is what killed the heater but you’d have a hard time proving that kind of accusation.

Take care of the pool yourself or else you’ll be buying heaters every 2-3 years.
 
I am not exactly sure, 20k gallon?

Its 5 feet on sides and 7 feet in the middle.

Opps I cut off last reading.

POOL SERVICE INFO
​
READINGS
5 ppm free chlorine
5 ppm total chlorine
7.6 pH
120 ppm total alkalinity
100 ppm cyanuric acid
​


1710792041583.png
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply