Print

[dwneast77]

Hi all,

About 3 years ago I purchased a slightly used 10 plate HX to use for my domestic water.  Recently my water pressure through the HX has dropped off terribly.  I just confirmed it by disconnecting it from my domestic supply lines and hooked a garden hose direct to it.  I only got a trickle of water out of it.  It is set up so it preheats the water as it goes into the water heater tank and has been a great setup until now.   Does anybody have any ideas about how to clean out/flush out the inside of a HX???  I am going to try letting it soak with white vinegar.  I'll let you know if that works.  Any other ideas would be helpful and appreciated.

Thanks!!

[mlappin]

Rig up some fittings then use a washing machine hose hooked to a puddle pumper, dump several gallons of white vinegar in a five gallon bucket, place the puddle pumper in the bucket and turn on for about an hour or longer. Should work better if the vinegar flows the opposite direction the water did.

[yotehunter66]

White vinegar or CLR, if it's calcium scale.

[dwneast77]

Mlappin,

Thank you very much for your input.  That is exactly what I had in mind to do.  I had already picked up a couple of needed fittings a few days ago along with a few I had on hand.  And I happen to have a 12v pump but had to borrow a battery that I knew my neighbor had.  First I just attached a some pex pieces which were angled upward making it possible to just dump vinegar into the HX and fill it up allowing it to soak.  The boiler side is still hot so that heated the vinegar also.  I let it sit that way for several hours while the family and I were out.   When I got back I set up the pump with a few gallons of vinegar and started flushing it out.  What a disgusting mess.  But wow did it work well.  I'll be making it a yearly ritual. 

Thanks again,
Jeff

[ijon]

Dino lab where my son works uses toilet bowl cleaner to clean them.

[kommandokenny]

Are the acids in the toilet bowl cleaner and CLR not destructive to the metal in the plates?
Could you soak it in Clr for a short time, then flush it with vinegar?
My dealer recommended CLR also,, but those bigger plate xch are$$$
Shame to damage it.

probably beat this horse before ??

[mlappin]

I think I'd stick to the vinegar, somebody else posted once they took a heat exchanger to a shop to be cleaned/repaired and were told by the shop owner the acid in CLR would eat the brazing eventually.

[Roger2561]

Question;  Should the house side (pressurized side) of the heat exchanger be flushed at the same time as the open side?  Roger 

[kommandokenny]

I think I'd stick to the vinegar, somebody else posted once they took a heat exchanger to a shop to be cleaned/repaired and were told by the shop owner the acid in CLR would eat the brazing eventually.

Martin I think I saw it on that thread also.[detrimental]
No one really challenged it though??

[kommandokenny]

Ya Roger, while ya got it off,,, might as well eh..
Still don't know how long I would soak it ...clr ate my shower head!!

[WoodMOJoe]

Question;  Should the house side (pressurized side) of the heat exchanger be flushed at the same time as the open side?  Roger

In my case it's not too bad yet but the house side is going to be the problem.  We have real hard water here (circulating through the house side), I used reverse-osmosis water with boiler treatment in the boiler loop and I don't think I have much restriction or deposits on that side of the hx. 

Either way, you should definitely clean both sides while you are at it.

[dwneast77]

I plan to clean both sides before startup next season.  For me it was the domestic side that plugged and when it decided to happen it happened quick.  It might be in part because I installed a water line for a humidifier and therefore shut off that water supply.  When I re-opened the water supply valve I guess it broke some chunks loose and plugged up my water flow more.  My theory is that the corrosion inhibitor on the boiler side may be helping to keep that side clear??  Couple that with the fact that it is just re-circulating the same water and not introduced to new water constantly. 

Side note about CLR.  I once put regular CLR in a spray bottle to spray a shower.  The mist just about killed me to breathe.  Never did that again.  Not a big fan of chemicals if I don't need them.  Figure vinegar is used to descale a coffee maker and I see this as being about the same thing, without adding chemicals to my domestic water lines.   

I too have hard water.

[Roger2561]

Thanks for the info guys.  I appreciate it.

Yeah, like you guys, I too have hard water.  There's gunk buildup on the shower head.  I'll be flushing both sides of HX when I shut down the OWB for the summer.  I'm almost afraid to see what the water looks like after a couple of years operating it.  Roger   

[kommandokenny]

House side is gonna bung up first, especially if you slap a plate on the old DHWT.
It's full of crap!!!!
Flush and fill,, ,add conditioner,, and the boiler side would not be affected as often.
My brilliant deduction

[WoodMOJoe]

House side is gonna bung up first, especially if you slap a plate on the old DHWT.
It's full of crap!!!!...

Om mone, since the hotwater tank is downstream of the exchanger on the domestic supply loop the plate shouldn't be getting any of the tank crap in it, should it?

Need to redo mine and put valves on where it is easier to pull it out of the system.  I might get another identical one and keep a clean one on hand at all times too.