New York Frozen Tankless Finishing

Discussion in 'Maintenance and Troubleshooting' started by johnny1720, Feb 18, 2015.

  1. johnny1720

    johnny1720 Member

    I have a HWG on my ClimateMaster 4 ton. I have a 50 gallon buffer that feeds an early generation tankless. The tankless froze on Sunday night it was -23 and a steady wind. I was able to defrost it and it worked fine. However it froze again later that day and is now destroyed. Heat exchanger cracked and water ran into the electronic controls. My breaker panel is full unless I install a sub panel. I am not sure I want another tankless or if I can afford another one.

    What should i do? The last time I filled propane in October it was $4.00 per gallon

    I currently have hot water directly from the buffer tank, so I have a little bit of time to decide.
  2. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Isn't the tankless inside? How can it freeze?
  3. johnny1720

    johnny1720 Member

    Yes indeed, the tankless is inside. When it gets that cold the stainless steel exhaust radiates cold air down the vent. When this happens the top of the exchanger freezes. This has froze about 4 times in the past. However this time it froze hard and cracked. Then it leaked and then it made a big mess.
  4. johnny1720

    johnny1720 Member

    Here is a video sort of explaining why my tank froze that I found online. My unit uses inside combustion air. However I had nothing in the house using combustion air.

    I am not sure how to prevent this and this was a $1500 investment 6 years ago.
  5. dgbair

    dgbair Just a hobby Forum Leader

    No room to swap in a few duplex breakers into the main panel?
  6. johnny1720

    johnny1720 Member

    Well I got great news today, the tankless had a 12 year warranty. Because of the location of my home they said it was a defect. They said it should be protected down to -30. It will be covered under warranty with little money out of my pocket. The replacement is scheduled to arrive on Monday.
  7. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    glad to hear
  8. TurboTom

    TurboTom New Member

    Will the new unit have a new design or how will you make sure it won't happen again? Do you need to check that your furnace has sufficient supply air?
  9. ChrisJ

    ChrisJ Active Member Forum Leader

    You may have to leave the hot water trickling when it's very cold out.

  10. johnny1720

    johnny1720 Member

    We do leave the water trickle when it is below 5 degrees.

    They said the new unit uses a concentric exhaust. Meaning the supply air is pulled from the outside. All of these units have a electric blanket that wraps the heat exchangers. I think that stopped working in my old unit. Either way -23 temps with the additional windchill values did not help the situation.

    My heat pump does not use any supply air neither does anything else I had running in the house.
  11. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Maybe retrofit some kind of freeze protection heater or solenoid water valve to dump or circulate a little hot water?

    Propane at $4.00 / gallon is a bum deal relative to electric resistance in most markets. $4.00 propane burned at 80% efficiency corresponds to 18.5 cents / kWh.
  12. johnny1720

    johnny1720 Member

    Yes I know it is expensive however I live with 2 little girls along with my wife , we have 3 bathrooms. I have yet to take a cold shower since the install of the tankless in 2009.

    And it is so nice to be able to run the dishwasher while you shower and do a load of laundry.
  13. pfer10

    pfer10 Member

    I had natural gas in my old house but the only thing on it was the furnace. I lived there for 11 years and always hated paying the $14 just to have gas to the house from April to November when I didn't use it. My electric hot water heater finally gave out and I put in a NG tankless to at least use some gas the rest of the year. It was so nice on those days you just wanted to take a long shower and wasn't forced to stop because of cold water. Of course if someone abused it that could be a bad thing also. lol
    johnny1720 likes this.
  14. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader

    Comfort almost always wins out over economics. At least by the time they phone us:)
  15. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader


    Nice thought. Can I use it? Had one of those jobs Friday.

  16. johnny1720

    johnny1720 Member

    New unit was here when I got home, it took about and hour and a half to install. I was unable to chaulk the thimble due to it being -1 outside. I used some foil duct tape around the thimble as a temporary solution (exterior of the pipe is the cool supply air). The thimble is oversized by about 5/8 of an inch. It leaves an extraordinary gap around the chimney. I am not sure I can chaulk it.

    The unit fired right up and is producing 130 degree water.
  17. pfer10

    pfer10 Member

    That was another benefit of the tankless that I liked that I never thought about until I had one. I like my showers on the warmer side. I set the tankless right where I could take a shower and not turn on any cold mix water to get the temp spot on. Day in and day out my showers were perfect. So easy to just turn hot water on and never have to mess with mixing cold to get that right temp.
  18. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    My thermostatic valve does the same. You set it where you want it, and that's it. :)
    Plus my wife and my teenage daughters can set it where they want it, too, without me running in the basement.
    That is kind of important, since they have a different physiology. They are under the shower for 30 min and sing, whereas I get 1st degree burring after 20 seconds, and scream.;)
  19. pfer10

    pfer10 Member

    Doc never thought of that. lol Now I got something to do in my new house this weekend that has a traditional electric tank water heater. :) Oh the little things in life. Is your thermostatic valve electronically controlled?
    Last edited: Feb 24, 2015
  20. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    No. Just a simple thermostatic shower valve.

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