Question about Hayward H Series Pool & Spa Heater 400k Btu Propane Gas Milivolt Ignition H400p1

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I have a Hayward HD100DI pool heater (3 years old) that I'm told needs a new heat exchange. I'm told they don't make them available anymore since it's too expensive of a repair to make and you're better off replacing the heater. I believe the problem happened when my daughter left the heater on for several days (water was a balmy 102 degrees), and now water leaks from that area. I'm trying to repair it without replacing. Any ideas on how I can do this? Thanks in advance, Boiling in New Hampshire

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  • A Miller Jun 04, 2010

    If you could get the parts ... by the time you have it installed ... and running ... you wil have about the same $ invested fort a new heater ... but you will have a three year old heater. If there is a copper smith in the area ... you might get him or her to repair ... I dont think it will ever be fight however. 102 degrees is dangerous. How is your water? Have you had it balanced? Do you check it? If the water is aggressive, there is a possibility that the water has damaged the heater.

  • Bob Camire Jun 07, 2010

    Thank you for the info. I'm trying one last fix to repair the leak (plumber's epoxy) and if that doesn't work, I'll use it as a boat anchor (all I need is a boat). Thanks for the advice of a copper smith - good suggestion!




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I just found the same problem after replacing my ingiter and gas valve this week. Leaks right above the new valve. I'm going to try JB Weld, which comes in alot of different applications, and you can get at most Automotive stores. It worked pretty good on an exhaust leak I had once. Good luck and I'll let you know how it works out. My heater is still heating the water but makes a knocking noise when starting and of course, the water is leaking.

Posted on Jun 09, 2010

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I had the same problem with a 10 yr old heater. You can get the whole heat exchanger assembly, but it is quite expensive. $700 - 900 depending upon the model.

I found on my exchanger that I had developed a leak in the copper right next to the manifold (large black plastic piece on one end of the copper). I tryed to solder the leak but had no luck from the outside. Dis-assembled the exchanger and tried to solder from the inside of the tube, again with no success. I finally cut the opposite side of the tube that was leaking to avoid steam pressure build up and plugged this one leaking element at the manifold. Here is the funny part, I couldn't find a copper plug to fit the id of the tube, so I used a synthetic cork from one of my wife's wine bottles and high temperature RTV, blue, the same that is used on automotive water pumps. Worked great!

This does reduce the total flow of H20 through the heater core, but solved the leak. I will be replacing the exchanger in the near future, but this got me through the winter and eliminated the water loss.

Posted on Aug 19, 2010

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Dad burned spel checker ..."I dont think it will ever be RIGHT however ..."

Check the temp on that eoxy you will be using ... of course if this is the last ditch effort ... might as well go for it. Along those lines ... there are lots of interesting epoxy type materials you might consider. Go to the Ace Hardware in your town and look at the offerings on the shelf. 'Liquid steel' might be something for you to consider.

Good luck on your project.

Thanks for your interest in

Posted on Jun 07, 2010

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