Max-E-Therm FULL OF WATER

learthur

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LifeTime Supporter
Sep 9, 2008
243
The Woodlands, Texas, USA
I have a Stay-Rite Max-E-Therm 400HD.
I have been replacing parts as it would run for a while and then quit.

Today I removed the HSI to replace and noticed half the tip of the HSI was submerged in WATER!!

So where do I go from here??

Do I disassemble the manifold and replace o-ring seals or check for a cracked manifold?

Heater is around 2-4 yrs old and I wouldn't expect a hole in the heat exchanger with the HD cupronickel exchanger....


Thanks,

Lee
 

ps0303

TFP Expert
In The Industry
Jul 6, 2011
3,977
FL
Remove one of the bottom header bolts and see if water comes out. If water comes out there then you have an issue with the heat exchanger. Replacing the heat exchanger is not an easy job. Just because you have cupro nickel heat exchanger doesn't mean that it's bullet proof. If you let your pool chemicals go with out keeping them in check for long periods of time it will eventually eat thru it. Cupro nickel with just take longer.

So remove one of the bottom bolts on the header and check for water there.
 

learthur

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Sep 9, 2008
243
The Woodlands, Texas, USA
I removed the lower bolts and about 10 gallons of water drained out.
I removed the entire manifold and took some photos.

I put my mouth on the copper loops and pressure tested each loop. No leak detected by mouth. Perhaps there is a pinhole leak that I can't detect that way.

Other than an undetected pinhole leak in the heat exchanger, is there any other way for that much water to enter the combustion chamber? Before doing this I had removed the HSI with the pool pump running and could see water in the combustion chamber but the amount of water was not increasing. If there was an active leak in the heat exchanger I would expect the pool pump to pump full the combustion chamber and then overflow. This was not happening, but the water got in there somehow. ????

Noticed the corrosion on a couple of the bolt heads. Those bolts were the bottom 2 bolts holding the manifold on.
I don't see any malfunction of the internal bypass valve or the thermostatic bypass valve.
No cracks in the manifold that I can detect.

Any ideas?

Thanks,

Lee
IMG_4868.jpgIMG_4869.jpgIMG_4870.jpgIMG_4871.jpgIMG_4872.jpg
 

learthur

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LifeTime Supporter
Sep 9, 2008
243
The Woodlands, Texas, USA
So thinking the combustion chamber was most likely damaged when flooded, I pulled it apart. Looks like a mess.

Any advice which parts to replace and which to keep?

I'm thinking new heat exchanger and o-rings PLUS new combustion chamber pan.

Thanks,

Lee
IMG_4876.jpgIMG_4877.jpgIMG_4878.jpgIMG_4879.jpgIMG_4880.jpg

- - - Updated - - -

Here are a few more photos.

Anyone have any recommendations for the vertical cylindrical mesh tube that delivers the gas? Keep or replace?

Lee
IMG_4873.jpgIMG_4874.jpgIMG_4875.jpg
 

kadavis

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In The Industry
Apr 5, 2015
1,485
tucson, arizona
Seems like the manifold tubing in your first picture looks okay, if it was just a chemistry issue these would show a lot of damage. Looks more like you have a lot of sooting going on probably from low gas pressure. Whether you fix or replace this heater I would do a gas pressure test before You fire it up. Can't really see the gas line leading to heater, what is the yellow flex line going to?
 

learthur

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Sep 9, 2008
243
The Woodlands, Texas, USA
The yellow flex line is about 24" long and connects the gas. I have a pressure meter, but not familiar with where to take the pressure measurement. I will inspect the gas line coming out of the ground. It's 1.5" metal pipe and corrodes every few years from rain and I replace it.
 

kadavis

TFP Guide
In The Industry
Apr 5, 2015
1,485
tucson, arizona
You can download the heater manual at Pentair Pool.com There are instructions on testing the manifold pressure. The flex gas line is really not recommended it is to restrictive
 

ps0303

TFP Expert
In The Industry
Jul 6, 2011
3,977
FL
The yellow flex line is about 24" long and connects the gas. I have a pressure meter, but not familiar with where to take the pressure measurement. I will inspect the gas line coming out of the ground. It's 1.5" metal pipe and corrodes every few years from rain and I replace it.
You have a leak in the heat exchanger and that needs to be replaced. Blowing into the tubes won't even come close to the pressure that is put thru the system. Have you priced out all the pieces and parts?

The flex line isn't code as they are made for indoor appliances. I would also replace that and use hard pipe as per code.
 

sholdr

Member
Feb 21, 2017
6
Dallas, Tx
Had same issue with first heater I had -- after several years it failed with water inside -- took apart and took manifold to a radiator shop and for $50 they fixed the hole and cleaned it -- worked another 2 years.

If u are handy can replace the manifold, but looking on line I found a new unit for about the same price as the parts -- saved the old parts as spares...
 

learthur

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LifeTime Supporter
Sep 9, 2008
243
The Woodlands, Texas, USA
Thanks for the feedback.

Since the heat exchanger appears to be in good condition, I am taking it to a radiator repair shop to have the leak fixed and pressure tested. Should be much cheaper than a new cupric-nickel at $1500 or a copper at $700.

I will see if I can test the NG pressure too.
 

Pool Clown

In The Industry
Sep 5, 2008
1,882
Silicon Valley, CA
Unfortunately, that heater is done. Look at the center of the picture along the right side. See that hole? That tub cannot be run like that or repaired. That will allow hot gasses to escape through it, and maybe "blowtorch" a bigger hole and perhaps even an exterior fire. Even if that hole wasn't there, that tub is in real bad shape.

Pinhole leaks, (95% of exchanger failures) take a long time to fill the tub up. You definitely won't visually see the water level rise.

Not sure if a radiator shop fix (with i'm guessing solder or brazing rod) will be able to withstand the temps that are subjected to the exchanger. I suppose you could try it, but like i stated, the tub wont last in its present condition.

As stated above, what ever you choose to do, you should check the gas line sizing.


View attachment 57527
 

ps0303

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In The Industry
Jul 6, 2011
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FL
Pool Clown is right. I know I would never ever suggest to a client to repair such a unit. But many DYI folks feel differently. If you add up your time and costs, you're at a new heater. Plus any added frustration that comes along after you repair and there are other issues.

Yes the hole.

tank.jpg
 

swimcmp

In The Industry
Nov 8, 2011
1,055
Moberly,MO
As a person in the industry from a liability aspect I would never suggest to anyone to repair any part of this heater. Should anything happen you would have a lawsuit on your hands.
 

JamesW

TFP Expert
Mar 2, 2011
13,821
I agree, replace the heater.

Also, the question comes up, why did this one fail, especially if it's not that old and has a cupro nickel heat exchanger?
 

ps0303

TFP Expert
In The Industry
Jul 6, 2011
3,977
FL
If the unit is that young as stated, 2-4 years old, then you either have poor water management. I have always stated that you can spend the extra $$ on cupro nickel and it won't mean a darn thing if you don't maintain your water correctly. It will fail just like regular copper but will just take a little longer.

These units also need the correct gas pipe sizing. These are not as forgiving as say the Raypak. Mostly because it is a closed burner chamber.

Unless you pressure test the heat exchanger you might find it hard to find the leak(s). But any case, I would not recommend repair but to replace it. But it's not my pocket book taking the hit. I've had customers beg me to repair it to just give them "one more season" then they will buy a new one. Well I fell for that line many times but when they call you next season and ask the same thing, well I won't do it.
 

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