Flushing a water to water heat exchanger

Discussion in 'Maintenance and Troubleshooting' started by ChrisJ, May 21, 2013.

  1. ChrisJ

    ChrisJ Active Member Forum Leader

    "hope your cleaning the DHW with some vinegar each year for 8-10 minutes either DeSuperheater or 100% Priority instant water heater."

    My hybrid HP has been running for 3 yrs. It has 100% priority DHW. This shoulder season it seems to be using more KWHs then previous seasons. (just running to satisfy DHW)

    Running longer because the exchanger is fouled? Should I add shut-offs and hose bibs to isolate heat exchanger for flushing?


    "And another floor-radiant/other oversized-HW -plate exchanger (using y-strainer, on all those)."

    The only Y-strainer my HP has is on the ground loop. The guy (ilikegeo), who went through 4 compressors had y-strainers on all, he said the DHW one kept getting clogged. Thought his 120 gal. of 130* water was not good for those compressors.

    ChrisJ
     
  2. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Chris:

    I never used to worry about cleaning heat pumps much, until some brown gooey growy stuff shut down a water to water unit in Morgan County, Ohio, that we did the design work for. The system was filled with "city water" and fouled in under 14 months of service.

    We used Furnox brand cleaner and then treated the water with their product and added a biocide.

    We clean our tankless systems with the Whitlam kit and chemistry.

    If you need more info let me know.

    Mark
     
  3. ChrisJ

    ChrisJ Active Member Forum Leader

    Thanks Mark,

    We have a lot of iron in our well water, used it un-filtered for 1 year. Now we have an iron filter, but may have some orange growy stuff building up in the HP.

    The ground loops were filled from my father-in-laws well which has no iron in it. Wells are only 250-300' apart, but his was made in 1970.


    Chris
     
  4. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Chris:

    Remind me. closed loop?

    Do you have "Y" strainers installed?

    Mark
     
  5. ChrisJ

    ChrisJ Active Member Forum Leader

    Yes, closed loop. 5- 200' trenches straight pipe 1", 7-8' deep. 4-ton HP.

    The only y-strainer is on the ground loop just before it goes into HP.

    Chris
     
  6. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Growey iron stuff likes the same temps that a radiant floor likes I just found out the hard way.

    Your system is newer, but could be incubating gooy gunk. Have you pulled the strainer mesh?

    Yikes.

    I would add a strainer on the house side of the system. I can put you in touch with a good water guy here in the Cleveburg area. Their cleaning and treating stuff is not free, but it works.

    If you filled the house side with your other family well and the system is now getting sluggish, I would bet your heat pump is creating conditions that help the gunk grow.

    What do I know.

    I just do this for a living, (sometime less than more), and I never stop learning about how the Earth goes around every day, with or without my knowledge.

    Give me a call and I think we can test for problems and then fix them.

    Mark
     

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