Is my heater ok?

[mick1putt]

My Max-E-Therm heater is 10 years old and was working fine when I last used it in May, but I have reason to believe it may be adding metals to my water, which I assume means it may not be so healthy on the inside. This relates back to a question I posted in July about my water turning green after I added chlorine. The answers all pointed to metals in my water, and my heater as a possible source of those metals. I checked and found, even though I hadn't used the heater in over a month, I was still running my water through the heater. I rerouted the return to bypass the heater for the rest of the summer, but now it's time to crank up the heater again.

Finally my questions-- Is it safe to assume my heater's innards are rusting? If it is rusty does that mean it's on it's last leg, and will soon need repair, or replacement? After the problems I had this summer, I don't want to add more metals to my water, so can it be cleaned, or flushed, or anything done to fix it? Who does maintenance or repairs for pool heaters, an HVAC person?

 

[JoyfulNoise]

The primary metal that shows up from a heater is copper as that is what the heat exchanger is made out of. Unless your water chemistry is off and the water is very corrosive (low pH), copper is fairly stable. Copper typically shows up as brown stains on pool surfaces. Green clear water is typically iron contamination as iron typically adds a yellow coloration to water and that mixes with the natural blue color of water to appear as green.

Do you fill with well water or municipal water? Have you had your fill water tested for metals?

It typical for a heater to be left in the return path with water flowing through it. Most heaters have a high-flow bypass in the header that allows most of the water to flow right out of the heater and only a small fraction to be allowed through the heat exchanger. This ensures that the heater adds as little head loss to the return flow as possible while still allowing some water to flow through. It is nitbtypically a good thing to completely bypass the heater unless you periodically allow water to flow through it OR you drain the heater when it’s not in service. This avoids stagnant water and scale build up in the heat exchanger.