TEKMAR 401 and DHW

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

McKraut

Feeling the Heat
Sep 1, 2011
349
South Central PA
Does anybody have any experience with a Tekmar 401 House Controller? I am having a problem because the DHW pumps are running non-stop and I am trying to adjust the temperature setting in the Tekmar. I have attempted to adjust the temperature so that the circulator will stop running when the DHW is >/= to 135*. Using an external thermometer on the body of the HWH, I get a temperature of 139* so that tells me the circulators should stop running. I changed the setting in the Tekmar for the DHW to 100* and I placed the tank’s sensor on the supply side of the plate exchanger (168*). I expected this to kill the pump because it would appear that the DHW tank was above the set temperature. The circulators did not stop. The Tekmar has a “View” function that should allow me to see what the current value the tank sensor is providing, but I can’t get the value to display. Is there a way to test the sensor to verify that it is working properly? Am I missing something?