Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Inability to make up hot water

Hello All,

I have a system 2000 that was working fantastically and now I've seemingly lost the ability to make up hot water in real time. I believe I've identified the issue but could use a reality check. 

The problem as I understand it, is the extreme temperature gap between my boiler supply and return temperatures. During hot water usage, the boiler will get the temperature and pass approximately 215° f water into the heat exchanger. Even without the domestic hot water circulator pump being on, the output from the heat exchanger back to the temperature sensor is only about 90° f while the system is passing the makeup water through the heat exchanger. The domestic out line to the hot water tank is also cool to the touch. This leads me to believe my heat exchanger needs to be replaced; as I can only assume I'm suffering from some sort of restricted flow on the boiler side, which is preventing the system from passing sufficient heat into the heat exchanger. Am I on the right track? 


  • JoeHNJ
    JoeHNJ Member Posts: 18
    You are on the right track. If the burner is shutting down on high limit while the Manager sensor is only showing a minimum temperature rise then you are not getting flow thru the Plate Heat Exchanger. It could also possibly be an issue with the boiler circulator. If you manually open a zone valve you can verify flow out of the boiler to verify that the circulator is functioning. If you like, message me with your contact information and I would be glad to go over with you.
    Joe Harazim
    Technical Support