How can I go digital on A/C that doesn’t cost half as much as a new A/C?

gotjeepzj · Post by **gotjeepzj** » June 13th, 2020, 12:51 am

I currently have a 2006 marinair 18K running off my old 3 knobs. My original marinair 16K a/c died and this was included with the boat. But it didn’t come with any of the I/O stuff. Quick google hits looks like almost $750 for the kit. I refuse to pay almost half the cost of a brand new 16K...there’s got to be something cheaper..can anyone help?

RGrew176 · Post by **RGrew176** » June 13th, 2020, 1:04 am

I think in the long run a new unit would be the best way to go. As has been said here in other A/C postings the newer units are more efficient, quieter etc. Go New.

gotjeepzj · Post by **gotjeepzj** » June 13th, 2020, 9:19 am

Normally, I tend to agree. However, this 18K was barely used when I got it. The guy traveled a lot and so it just sat

tomschauer · Post by **tomschauer** » June 13th, 2020, 9:42 am

If its working off the old three knob control you should be able to convert it for use with a standard home type electronic thermostat. What functions are you looking for that you dont have now?

gotjeepzj · Post by **gotjeepzj** » June 13th, 2020, 10:36 am

For starters the pump runs any time the blower is on instead of just when the compressor is on. The problem with that is in the summer the lake gets to be about 88*F. So I use the ac, cool down the boat, the compressor kicks off but the pump and blower stay on. It doesn’t take long for the warm water to turn my ac into a heater...and once the boat gets warm enough, the compressor kicks back on and cools it down. I have the opposite problem in the winter. I also don’t like the idea if a 500gph Pump running continuously all day with nobody home. I would also like a digital thermostat so I know what the temp is supposed to be. If anyone knows how to wire a home thermostat in, that would be perfect.

tomschauer · Post by **tomschauer** » June 13th, 2020, 11:12 am

The pump should be an easy enough fix. Move the pump feed wire from the fan relay to the compressor relay.
If you get the model and serial number from the a/c unit the schematic can be found and wiring for a different stat can be determined.

gotjeepzj · Post by **gotjeepzj** » June 13th, 2020, 6:41 pm

Here it is. I couldn’t find anything.

g36 · Post by **g36** » June 13th, 2020, 8:31 pm

Do you mind posting pic of what thermostat your currently using?

BenTen · Post by **BenTen** » June 13th, 2020, 9:55 pm

I converted my old 3-knob control to an SMX-IR digital control by getting the SMX board, enclosure/box, and thermostat from someone with a bad unit. It just took matching and converting the wiring over from one to the other.

This is the wiring conversion drawing that I came up with, note the matching colors from the 3-knob control:

2020-06-13_21-54_Knob-Conversion-To.jpg

Hope this helps!

vineyardgray · Post by **vineyardgray** » July 29th, 2020, 4:22 pm

Are the color codes for the three wire controls proprietary to Marine Air/Dometic or are they standard t-stat wire code?

I have been looking into this as well as I am about to purchase some new Air Conditioning units and I don't want to be locked into proprietary codes, proprietary t-stat, proprietary circuit boards, etc.

I want regular old "standard" HVAC stuff with relays instead of pcb's wherever possible. I want to be able to fix it with off the shelf stuff.

I have been eyeballing the BraeBurn BlueLink WiFi T-stat. Lotsa whiz bang features and half the pain of proprietary units.

Incidentally, it is also the model that Flagship Marine sells as an upgrade and their ethos is along my lines - K.I.S.S. (Keep It Simple Sailor)

How can I go digital on A/C that doesn’t cost half as much as a new A/C?

How can I go digital on A/C that doesn’t cost half as much as a new A/C?

Re: How can I go digital on A/C that doesn’t cost half as much as a new A/C?

Re: How can I go digital on A/C that doesn’t cost half as much as a new A/C?

Re: How can I go digital on A/C that doesn’t cost half as much as a new A/C?

Re: How can I go digital on A/C that doesn’t cost half as much as a new A/C?

Re: How can I go digital on A/C that doesn’t cost half as much as a new A/C?

Re: How can I go digital on A/C that doesn’t cost half as much as a new A/C?

Re: How can I go digital on A/C that doesn’t cost half as much as a new A/C?

Re: How can I go digital on A/C that doesn’t cost half as much as a new A/C?

Re: How can I go digital on A/C that doesn’t cost half as much as a new A/C?