help with Webasto FCF 16k

[KandD]

I just installed our new AC we bought last august (hot-humidity motivated) and it works GREAT! except for one small problem, the thermostat thinks it's 20 degrees cooler in the boat then it actually is. So instead of it cooling from 85 to 65, it goes from "67" to "65". I tried running it on heat, dehumidify, power cycling, unplugging, sacrificing the old unit to neptune... nothing.

Anyone have one? Tips?

 

[Benny]

Lost you there. Is the unit cycling off prematurely or is it just the display showing 20 degrees off or both?

 

[KandD]

Just 20 degrees off, says the cabin is 65, my weather station says indoor temp is 85. The two are on the same bulk head maybe 4" apart.

 

[MrUnix]

There should be an adjustment screw inside the thermostat so you can calibrate the temperature reading.. what model thermostat do you have?

Cheers,
Brad

 

[KandD]

..... the one that came with it

I can't find a specific model for the controller; it's the one that comes with the unit. The unit model number is FCF0016000.

I'm wondering if the room-temp sensor is on the unit and not any of the controllers. I may have a leak in my ducting that is short-cycling the system...

 

[KandD]

Turns out my attempts to plump in the AC into the existing ductwork is what caused the problems. I've disconnected the main line and vented it straight up. The actual temp dropped as the display temp rose up and the two met in the middle when I decided 70 is cool enough.

 

[Barnacle Bill]

Ever consider calling the manufacturer for an answer?

 

[KandD]

I sent them an email last night, got a reply today. The thermostat is on the pan in the path of the return air. What the ACTUAL problem was, was that the existing duct work caused too much air restriction, which popped my duct-tape seal on the blower. This resulted in it short cycling.

I've repaired the hole and it's just blowing into the main cabin. It got chilly on board last night, so I'm not going any further with it for now. Next I'll run some new ducting to supply two vents in the aft cabin and a second vent in the main cabin. Those should do away with the air restrictions and make everything more efficient.