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[joe a]

My water-to-water plate exchanger no longer functions well, so I figured it was plugged up.  My exchanger was plumped with hose spigots to facilitate flushing.  Here's the procedure I followed to clear things up: I flooded the plate exchanger with CLR and let it soak inside for 24 hours; I flushed the exchanger both ways using clear krylon tubing so I could see what came out; I got some gunk out, but I saw no improvement in function.  In addition, I now have greenish, stinking water when I first use hot water, even six days after performing my procedure (I have a on-demand propane unit plumped downstream, and it supplies my hot water now and during the summer).  This greenish, foul-smelling water does clear up if I let the water run for a few minutes, but the next time I use the hot water after down time, the greenish, stinking water at start up reoccurs.  I do have the bleeder setup, which I have set to no bleed.  I think the bleeder system, for my use, was a waste of money.  From what I can tell, if a plate exchanger needs cleaning after a few years, the investment in the equipment and the loss of energy associated with heating water is not worth it.  I have a water softener upstream of the plate exchanger, so I anticipated no calcium buildup or any clogging issues.

What flushing techniques work?  Has any one used vinegar as a way to avoid introducing chemicals to his potable water?  Any suggestions would be greatly appreciated?  Thank you.   

[hoardac]

In my old house the only thing I ever used was muratic acid / water in a 5 gallon pail and a sump pump, ran it for 2-3 beers. Never really timed it, my buddy showed me how and it took a 6pack for 2 of us to finish it, so that's how I time it. Worked well every time after that. Just be sure to wear glasses and gloves.

[cantoo]

Now sure where but I did read somewhere that you are not supposed to use CLR on plate exchangers. Something about the way they are soldered/ welded I think. Have you checked your anode rod lately? They cause the water to smell. My plate exchanger is brand new so I have never cleaned it. They are built pretty simple I have no idea why yours wouldn't be working. Does it feel hot to the touch?

[sw18x]

I just used a product called flow-aid to clean my HX. Non toxic, you can flush it right down a sewer, not sure about potable water but it really cleaned the system out nice. About 40 bucks a gallon.

http://www.flow-aide.com/

[RSI]

That is why I like installing unions at the plate instead of flushing valves. That way you can take it out and clean it completely then flush it so nothing gets in your pipes.
You can make up bypass pipes if you don't have bypasses so you only need to shut the system down for a couple minutes.

I can't remember if it was muratic  acid or something that was sold as a replacement for it at the hardware store.

Just pour it in with the ports pointing up and wait till it stops bubbling out. Then flush it with water and repeat the acid. Keep doing it till it doesn't bubble up and looks clean inside.

[Jack72]

That is why I like installing unions at the plate instead of flushing valves. That way you can take it out and clean it completely then flush it so nothing gets in your pipes.
You can make up bypass pipes if you don't have bypasses so you only need to shut the system down for a couple minutes.

I can't remember if it was muratic  acid or something that was sold as a replacement for it at the hardware store.

Just pour it in with the ports pointing up and wait till it stops bubbling out. Then flush it with water and repeat the acid. Keep doing it till it doesn't bubble up and looks clean inside.

How often do you guys flush yours?


 I know it would depend each other's water hardness/lime

[RSI]

You only need to flush it if you notice it not working as good.
Mine has been going for 10 years and has never needed to be flushed.

[slimjim]

Jack, good for you on the unions, I do both unions and purge ports with ball valves on all 4 ports at all my installs, I can pump coil cleaner through the heat exchanger without taking anything apart and have it as clean as new without contaminating anything else in the system in about 20 minutes.

[victor6deep]

I am just gonna change my water every 3 years and add chemical like normal. I will probably run 5 gallons of vinegar when I do the summer flush next year.