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NTI boiler lacks DHW

I have a five year old NTI boiler. In the last two weeks I have had no heat which required  replacing the  low water shutoff due to a leak. This fixed the heat for a week or so, then no heat again (but we did have DHW).  They replaced the 'three way valve'. We then had heat, but the DHW has become tepid. Even shutting off the tempering valve, the DHW is barely warm. They are now trying to flush the heat exchanger.  ( the water here, from a drilled well, is high in iron). DO they know what they are doing?


  • SlimpickinsSlimpickins Member Posts: 322
    Too much flow?

    I take it you have the combi unit? NYT recommends a flow reducer on the DHW inlet. The orig. installer may have used a ball valve to throttle down flow to meet flow rates and someone opened the valve all the way open? The first thing would have been to figure out what the flow was going thru the flat plate heat exchanger. Perhaps your service guy did that and determined the HX needed cleaning. Get on the horn with NYT tech support if you still have problems, they're very helpful.
  • RobbieDoRobbieDo Member Posts: 131
    Had that issue once

    Slim is correct, you need to control incoming water to the tankless in the unit. Was there a LWCO installed in the system besides the systems pressure switch? Regulate domestic incoming water, check plate heat exchanger for flow, make sure boiler is going to priority for domestic hot water, these are some things to check. Let us know what you find.
  • SlimpickinsSlimpickins Member Posts: 322

    Well, did they fix it?
This discussion has been closed.


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