Dometic Emerald Troubleshooting

[DWJensen]

Looking for some input / confirmation regarding an issue with one of our Dometic Emerald A/C units.

History: A few days ago our raw water strainer clogged and both A/C units shutdown with the control panels both flashing "HPF". I cleaned the gunk out of the strainer (Chesapeake in the summer) and tried starting both units. One started up but there was no flow out the thru hulls so we shut them down. I then flushed the system with fresh water and tried again. Once again only one unit would start. We did have better flow overboard, but still not as good as before so I ran 1:4 Barnacle Buster solution through the raw water system (shared by both units) for an hour then did a fresh water flush. That gave pre-shutdown water flow but still only one unit would start. The other still flashed "HPF" immediately.

The instant "HPF" code make me think that the HP switch is stuck open. To test I removed both wires on the switch and checked for continuity between the terminals - none. I them jumpered the two wires together and tried starting the unit and it started right up with no code. Yeah, bad switch.

Here's where I'm looking for input / confirmation:
I need to replace the HP switch and it appears to be simply screwed on, but I want to make sure this can be done without having to evac and recharge the unit. I've read that "some" units have schrader valves and switches can be easily changed. Any way to determine if that's the case?

Here's the info on the unit:
Dometic Emerald DEU16-410
MFG # 201150160
SKU # 9108893454

Thanks for any input.

 

[DWJensen]

UPDATE

After doing some more online searching I found more conflicting info so I figured my best option was to go to the source and see if I could get an answer from Dometic. It took some button pushing and a couple of transfers but I was eventually able to talk to tech support and was advised that these units do have Schraeder valves and that I should be able to change the switch with minimal gas loss.

 

[Turtle Blues]

Yes that is correct. It is on a schrader connection. You can remove and replace at any HVAC parts supplier, nothing marine specific about it. Trip pressure should be identified on a tag on the sensor, make sure to match. Some other brands have a history of using sensors that tripped too close to operating pressure.

 

[DWJensen]

As a follow up for anyone who might experience this same issue and find this thread, a new HP switch was the ticket.

I'm happy to say that I was able to source an exact replacement switch from TampaBayMarineAir.com and they shipped it out Priority Mail that same day. A few warm few days later it (along with a dab of "Leak Lock") went on, and once again all is cool aboard...