Water Furnace Premier II
I have worked on commercial water source heat pumps but never water furnace. I got the call it wasn't working. The drain light was on so I vacuumed out the drain. I pulled the covers and the pan was bone dry and I poured water in the pan which drained freely. I powered it up and it ran fine.
I got a call to go back for the same problem. Again the Drain light was on and the unit was bone dry inside. Drain line clear. I killed power and restarted it. It ran for a couple minutes and an amber DHW light came on. This unit has two water inlets and 2 water outlets. the top in/out is marked DHW which I am guessing is domestic hot water. Admitting I know nothing about this thing I didn't want to get too involed. I did turn on the hot water in the kitchen to see if the light would go out which it didn't. After a period of time the compressor shut down. The blower kept running. Then after a little while the DHW light went out and the unit started up again. The unit did trip off on the Drain again and when I checked the unit was bone dry.
While it was running I noted the top of the accumulator was warm to the touch rather than cool or cold.
One item of note that may mean nothing. This H/O has been using diposable filters for years. Recently he changed to a washable electrostatic filter. the filter was not dirty.
Also while looking at the control information I saw a dip switch selection that let me switch trouble codes to LEDS on panel. when I turned it in the on position the unit did not start and had Drain, HP, and LP lights on. When I put it back to off it returned to the previous behavior. If it is something simple I'll give it a shot otherwise I am tempted to refer him to water furnace dealer. As always any help is appreciated.