I have a 10 year old WaterFunace Premier2 unit (model Model: ATH028D110NLS) with horizontal loops, and the water heater circulation pump got a pin hole in a weld this summer, so the unit shut down. I wasn't here, but the local small-town HVAC people (who don't know how to work on WaterFurnace stuff) said the pin hole was spraying water on the circuit box and shut the unit down. They removed the pump (and let the unit run with out the hot water heater bypass), and after a month of them not fixing it (but billing me for a complete job), I called a company in the big city with lots of WaterFurnace experience. They replaced the pump and everything was fine. Just a few weeks ago (after about 3 months with no problems), the unit shut off in the middle of a cold night. I checked the error lights on the unit and the 'air flow' light was blinking red. I change the return filters every 3 months and it was only 2 days until they were due for a change, so I changed them. Then I turned the circuit-breakers off to the unit and heat strips for 30 seconds and restarted the unit. It ran fine. I also changed the electrostatic filter in the plenum later that afternoon. The unit has shut off 3 more times with the same error ('air flow' light was blinking red), mostly when it was cold outside. I cycled the power as before and everything is fine. Before I call the people in the big city (1.5 hrs away) and pay for a big service visit, do you have any advice?
air flow Chris, how is low air flow detected? Do they actually measure the air flow or is it a air temperature delta? Thanks
An Airflow Lockout on the Premier board is initiated by a loss of RPM signal from the ECM blower if installed. It is possible the water leak has corroded a connection anywhere from the Premier board to the ECM power and control harness or the blower is on the way out. The Premier board dip switch SW3-3 can be switched to No RPM to ignore the fault. This may help diagnose where to look next (ECM or wiring, connections or control board).
DLS, We apologize that we have not responded before now, as we have just found your post. We hope that you have been in contact with your contractor to discuss these concerns. If your contractor is unable to provide a resolution, please have them contact our technical support staff and we will be more than happy to offer our assistance.
I will check the fin coil for debris and the contacts for the circuit board to see if they are corroded. If I still have problems, I will contact the service techs in the big city. They were just here to replace the water heater circulation pump, and I would think the would check out the circuit board contacts for corrosion since there was a leak. But maybe not. Thanks for all your comments.
I had a unit we installed do the same exact thing as you describe. The unit operated great in between errors. I would say over a 6 month period, it happened 10 times. After multiple trips, we monitored everything from temperatures, pressures to power quality at the home. We found that the unit was operating at what we believed perfect condition. About 18 months ago, I used the dip switch setting to ignore the RPM fault. It has been 18 months and have not been called back.
