Does anyone know anything about Due-therm roof-top airconditioners? I've got a model 590 (1980s?) on my 42 Gibson that know longer cools. I checked their site for a service manual, but there's no info for anything that old. Basically I'm just wondering if anyone has ever had to recharge one of these. I was an auto mechanic for 15 years so the first thing I noticed is that there's no fittings on the high or low side to check pressures or to re-charge, and there's no site-glass on the reciever/dryer so you can check it visually. The compressor still runs, so either these things do not have low pressure switches, or the charge is fine and I have another problem. I'm sure I'm supposed to use a saddle valve, but I figure someone else has a lot of experience with these or is an expert so I thought I'd ask. Thanks

Tonka

Hello Tonka; I do air conditioning for a living and take it from me it is easier and cheaper to replace the unit than to repair it( if repairable). a lot of the older dou-therm units had ports to put gauges on with but it took a special valve to open the ports and check pressures. none of these have any low pressure cut-outs (or high pressure cut-outs) they dont put on normal gauge ports because of there small freon charge, usually less than 2lbs, if they did you would be low on charge after a couple times putting on the gauges. the compressor running and not colling is one of 3 things(none good) out of freon/ time to find the leak, blown valves/ replace the compressor, broken crank shaft/ replace compressor. while the old units were built like tanks and the new ones aren't( read cheap covers that crack if a duck walks on them) they are more efficent and pull less amps. 5 years ago i replaced both on my 43 Nautaline and the 15,000 btu model pulled less amps than the old 13,500 btu model and they are a drop-in swap. for the money and comfort on those 100 degree days replace them and work on more important things , like installing a beer tap in the frige, (the wife won't mind).

Good Luck

GO BEARCATS !!!!!!!!!! Weclome Home Mick !!!!!!!!!!!!!!

A bad day on the river with-out AC still beats a good day at work

Thanks MillerTyme, but that sorta' blows.(In more ways than one, I guess). What you say makes sense, so I think we'll continue on with just the front unit for a little while longer. I haven't checked prices, but I'm sure it's out of my price range this summer. Plus I'm in a covered slip which helps those 100 degree days. Thanks for your expert advice. I know who to ask the next time I have an ac question. By the way, is your old nautaline (the one you posted a photo of) now named the Hawaiin Punch or something like that?

Tonka

Ahoy Tonka; you are correct except the new name on it is Hawaiin Funch(play off new owners name). If you now the boat then you know the area,(Lighthouse Point). For a price on a new rooftop AC go to Deirking (the ice house on Ind 350 at US 50) that is were i got mine and i want to say they were about $ 500.00. After removing the old unit it usually takes longer to prep the opening( cleaning off any old foam tape or caulk) than installing a new one.As for the covered slips they sure do help the AC cool the boat, and to the other extreme if you carpet your rear cabin roof it will make it harder to cool your boat since the carpet works like a big sponge absorbing heat. My farthers cabin roof is carpeted and the only way to cool the cabin on a sunny day in the 90's is to wet the carpeting down.

P.S. have plenty of torpedo juice with you before you start any boat repair.



GO BEARCATS !!!!!!!!!!!!!!! Welcome Home Mick !!!!!!!!!!!!!!!!!!!!!!



A hot day on the river STILL beats a good day at work !!!!!!!!!!!!

Very cool. Thanks MillerTyme. That's a lot less than I was thinking and I most definately will check into Deirking; it sounds like the hot tip. That's an interesting fact about the carpet on the roof-top and the best reason I've heard yet for me not to put it on. You're right, I know the area. I live right across the state line in Ohio, and I just happen to have been working on a job in Rising Sun. I just happen to be such a large boat Geek that it's physically impossible for me to drive by a marina and not stop to look at the boats. Sad but true. Thanks again for the advice.

Tonka

I concur about just replacing the whole thing. They are relatively cheap and easy to install though you will need a second strong back to help you muscle the old one out and drop the new one in. Don't forget a new set of gaskets. You can get them with or without a heating unit. Go for the heater, it is only a few more bucks. I put Van-Pans under both of mine but you have to use an extra gasket and replace the threaded rods with longer ones to compensate for the pans.  

Thanks Judge. I've got the heater now, so that's definately what I'll replace it with. What's a Van-pan?

Tonka