Yanmar coolant system

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Gadzooks!
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Yanmar coolant system

Post by Gadzooks! »

Early on, after taking delivery of our MV34, we noticed small quantities of antifreeze below the engines. Eventually, we had to remove coolant several times from the plastic reservoirs as they filled to overflowing. Upon return from our Alaska cruise this summer, we had it looked at by a Yanmar dealer. He discovered the engines were low in coolant and deduced that the coolant overflow was transported into the reservoir when the engine heated, but was not sucked back into the heat exchanger when the engine cooled. He found the reservoir cap did not have a hole to admit air. Thus, when the engine heated, air and coolant escaped by forcing the cap up. However, when the engine cooled, the suction sealed the cap and did not admit air so that the coolant could not flow to the heat exchanger. He made a hole in the cap; problem solved.

Wally Gilliam
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Yanmar coolant system

Post by Stray Cat »

Hi Wally and Mebs,

Thanks for the gift of info, we see the same problem keeping coolant in the system, hopefully this simple trick will fix us up too!

Welcome back, we would love to hear about your cruise!

We didn't bring Stray Cat to the Sound this summer as we were providing hospice care for Candy's mom; who passed away in late July. We took her ashes down the Columbia to a lovely spot above Astoria last weekend, so she finally got a ride on the boat.

By the way, you guys were wise to install diesel heating. Our heat pumps fail to heat and freeze the heat exchanger when the river water was at 39 degrees last winter; and as Mebs no doubt noted in Poulsbo, cooling without window shades and with harbor water in the 80's was marginal. I will pass on fussing with the warranty from the Mermaid factory and have the system tweaked and tuned up locally, and I am planning 95% sunblock external window shades and a diesel central heating system before long.

Passed a wood chip barge last weekend named "Chips Ahoy."
Candy Chapman and Gary Bell in Stray Cat, MV34 hull 12
Aquila 32/31
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Re: Yanmar coolant system

Post by Aquila 32/31 »

Stray Cat wrote:.......................Our heat pumps fail to heat and freeze the heat exchanger when the river water was at 39 degrees last winter; and as Mebs no doubt noted in Poulsbo, cooling without window shades and with harbor water in the 80's was marginal................
That's interesting. Could you say what size a/c system you have installed? Do you think that going up one size would have helped with cooling?
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SecondWind
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Heating and cooling

Post by SecondWind »

Heat pumps will not produce heat at temps below 40. We supplimented with an oil filled radiator type heater in each hull and shut the pump down below 40. (16,000 BTU A/C unit. We also have cooling problems because of the enormous deck area. Deck shades help a lot, plus we use a carry-on on the main cabin top to keep comfortable during the day. Our regular unit is all we need at night.
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Yanmar coolant system

Post by Stray Cat »

Reply to Acquilla 32/31

My system has 16K Mermaid unit in the saloon and 8K between the staterooms. Size will not help here, as there is too little heat available in such cold river (or sea) water. A limiting problem in systems like ours is that the river water freezes as soon as it enters the A/C unit's heat exchanger, bringing everything to a halt and potentially burning up our sea water pump. One improvement will be a "keel cooled" system, where a 50% antifreeze solution circulates between the heat exchanger in the A/C and an additional exchanger outside the hull. The antifreeze is not as cold as the refrigerant in the A/C plus the water under the boat is a huge heat sink, less likely to freeze than the littld piddle passing through my system now.

Presently I use "ceramic heaters" in each hull to prevent freezing in cold weather, and plan to install a diesel forced air system for comfy cruising here in the Northwest.

The problem at the other end of the thermometer is also not going to be solved with more BTU's. Our system frosts up and stops air flow if we demand too much of it in hot weather. We set it at higher temperatures than we would prefer and hang towels and other stuff over the generous windows. Shade control is the real answer here, and I am fabricating sun screen fabric panels that snap over the outside of my greenhouse of windows. Our decks, hull and bulkheads are foam cored, and it seems to me when I touch the inside surface in hot weather that they are not inordinately warm, therefore I don't think they are transmitting too much heat to the interior.

I have already suggested to the Admiral while discussing more tropical cruising grounds, getting several burro loads of palm fronds and making a gigantic palapa over the whole boat for those hot summer days in the Sea of Cortez. Probably have to hose out the spiders every now and again....
Candy Chapman and Gary Bell in Stray Cat, MV34 hull 12
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