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NTI TRX110C Gas combi - no hot water daily

RhodeIrish
RhodeIrish Member Posts: 1
in Gas Heating

At our wits end with an NTI TRX110C gas combi unit. Installed 12/2020 and we are consistently having issues with not getting hot water.

We’ve had two companies come out and nobody can seem to diagnose the issue. One company, the one who sold us and installed the unit, has now washed their hands of us as clients (we filed an AG complaint for full transparency). The second was out Tuesday, said everything looked fine. They left - we have had no hot water the last 2 nights. Second company was recommended to us by the NTI regional sales manager. We are getting ERR9, 1P1, 5P1-5P6 error codes sporadically. Manual resets are hit & miss on if they’ll work to call hot water back.

Do we wash our hands on a 5 year, ~7k install, or keep troubleshooting? Located in RI - heat isn’t on yet, so this is solely a hot water issue for now. Anyone have experience with these units? We’ve reprogrammed motherboard 2x, replaced igniter, replaced heat exchange, valves, and a slew of other work. I currently have a new motherboard and heat exchange on our kitchen table given to us by NTI RSM.

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Comments

  • mattmia2
    mattmia2 Member Posts: 14,136

    what were the combustion analysis numbers and the gas pressures?

  • clammy
    clammy Member Posts: 3,232

    i usually reframe from comments as of late but in all the years this unit has been in service, has anyone open the boiler up and cleaned and serviced it as described by the manufacturer ? Has the flat plate been flushed an backwashed ? Has the water quality been tested and checked . Has anyone checked all the things most who are pros or at least though of as like to check ,inlet gas pressure ,combustion numbers td across plate on both domestic and boiler ,has anyone checked the proper operation of the 3 way valve while calling for portable water. Personally i have always stayed away from combi and stuck w indirect tanks and mixing valves being most only call for maintenance when its already a no heat no water call so much for maintenance one of the undune things in the heating world. saddest part is usually that there are only a few who go and do whats is suppose to be done and even fewer who are willing pay for it and or see any value until it dont work and in our great society w some one holding a bag it s often just replaced keep the world turning and all things burning .

    clammy

    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating

  • GGross
    GGross Member Posts: 1,606

    alright I can't get 1p1 to come up, but looks like you have a pressure error and ignition errors. Pressure errors are easy enough to treat, fill the unit to the appropriate pressure and purge all the air, if it drops again that means you have a leak! thats the hard part. the TRX looks like a water tube style boiler so its going to be a flow dependent design, you must have the air purged and no leaks! leaks will cause pressure drop and air due to makeup water.

    Then you have ignition errors, start with fuel type setting on the equipment, make sure it was properly converted if applicable. now check the gas pressure, 4 values, static, at ignition (or attempt) at high fire (if it gets that far) and lock up pressure at shutdown. if the pressure drops either below spec for your fuel type, or 1" wc+ then fix the gas service!

    once you can get the boiler to fire steady for space heating, check and tune the combustion to be in range of factory specs!

    Now test the DHW side, one thing to look for after 5 years, is debris slowing flow through the DHW side of the heat exchanger such that the unit is not firing? is the mixing valve cleaned and functional? are your fixtures allowing enough flow to start the unit?

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