2021 R27 LE Webasto Marine Air Conditioner

[Barco]

Hi,
When I use the the Webasto A/C unit in heat mode the system will supply heat to the cabin for a couple of minutes and increasing the temperature by a couple degrees and then the compressor shuts off prior to reaching set point, and then only the fan is on. Then a couple of minutes later the compressor will start supplying heat to the cabin for a couple of minutes more, and then the compressor shuts off again prior to reaching set point. After approximately 20 minutes of the compressor cycling on and off several times I shut the system off. My understanding is that the A/C unit should remain in heat mode supplying heat to the cabin until the ambient air reaches set point. I removed the return register and placed the temperature sensor in my hand to heat the sensor and the temperature display increased from 63 to 81 within a few second thereafter, the sensor seems to be working. I would appreciate any assistance in figuring out the possible corrective actions. Thanks, Louis

 

[DMD3]

That pretty much described the way ours behaves as well. I have the sensor laying right on top of the return air intake vent. While I am satisfied with the overall temperature control, one thing I am going to try is locating the sensor somewhere in the cabin away from the unit itself to see if it reduces the cycling. Having it just a few inches from the Webasto unit itself may be causing the shorter cycles. I noticed there is a fair amount of sensor wire coiled up under the helm seat (which I currently have removed).

 

[Barco]

Dave, I appreciate your feedback. Louis

 

[scgck]

Ours does the same.
Chris

 

[Barco]

Thanks Chris.

 

[scgck]

Just a follow up on the heat mode of the Webasto AC unit
I talked to a tech guy at Webasto and described the issue of the compressor cycling before selected temp is reached in the heat mode. He assured me that it was normal for the compressor to cycle frequently in the heat mode as this is what he called a secondary mode ,as opposed to the ac mode , of the unit. No problem. Let it cycle.
I also asked him about my inability to control the fan speed. He said the difference between high and low speeds is only about 200 rpm and we probably couldn't tell the difference by the sound. Just the way the unit was designed.
Let's face it, we have ac/heat in a phone booth and we probably should be glad it works at all.
Hope this was helpful,
Chris

 

[DMD3]

Agree 100%. On a side note, I found that if I ran the fan on a lower speed in cool mode the coil freeze protection kicks in and shuts down and throws that error code. Not enough air moving across the coils to prevent this. It fixes itself as the ice melts but advice I got was to keep fan on high speed at all times.

 

[Barco]

Thanks Chris and Dave for the additional information and glad to know there’s no problem with the AC/heating unit.

 

[Jcat2010]

As per others, we also saw short cycling in heat pump mode. Good to know that is "normal" for the fcf. I would be interested in how different locations of the return air sensor affect AC and heat pump modes. We never saw the readout matching what our "room temp" was. And when I got into it I found our sensor in a coils against the hull, nowhere near return grill. Moved it since, but won't have the chance to test it until spring.

 

[Grubin]

The saloon Webasto A/C in my 2022 RT 29CB, in heat mode, cycles off after a minute or so, then starts pumping heat again. Webasto claims this is caused by a restriction in the outlet air flow. After two years of trouble-shooting, we find that the unit will run continuously in heat mode if both 4" outlet ducts and the 5" to 4" Y transition is removed. However, if just the small Y transition is replaced with no ducting, the unit shuts down.

My initial thought was that the unit was defective. Wabasto doesn't agree. It's becoming obvious that Ranger Tug has supplied an inadequate A/C unit that will not function as intended in their boats. I bought and want a reverse heat function in that unit. For the Webasto factory to suggest to use it in a short cycle mode is unacceptable to me. I hope that Ranger finds an acceptable solution.