Stretch the season without worrying your pipes will freeze

Post your technical questions or solutions about your boat's plumbing here.

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Bob MacWright
Posts: 15
Joined: Mon Aug 06, 2007 11:30 pm

Stretch the season without worrying your pipes will freeze

Post by Bob MacWright »

I kept the boat in the water longer this year, and worried that some nights when I wasn't there, it was getting quite cold. I happened to use up the water in the aft tank one weekend, and quite by accident it dawned on me that I could keep that tank empty, and use it to blow the water out of all my plumbing before I left for the week. Now when I leave, I just switch back to the empty aft tank, then open the cockpit shower hot and cold lines (I removed the showerhead and stowed it below), and wait until nothing but air is coming out. Then I do the same for the galley, head sink, and head shower. When everything is blown out, I shut off the water pump. But, you may say, won't that hurt the pump? I don't see how, since the pump is a diaphram pump; the motor is moving a diaphram, and doesn't really care if it's water or air. When I come back next weekend, I just switch to the full forward tank, and reverse the process. The water temp is still over 50 degrees, so the tanks and hot water heater won't freeze. I also have two West Marine electric cabin heaters that come on if the temp goes below 49.

Now when I see that the temp will go down to 29 degrees at night during the week, I sleep like a baby.
EvenKeel
Posts: 33
Joined: Tue Mar 27, 2007 3:06 pm
Location: Carlisle, PA (slip-Herrington Hrbr, MD)

Post by EvenKeel »

Bob:

You may want to reconsider.

The water pump will pump air, but not at a very high flow rate. When you turn the pump off, residual water will flow back to the low points in the system. This probably won't hurt hoses, but could crack fittings, or particularly the manifolds, if it froze. An air compressor, however, is capable of blowing out almost all of the water. This works particularly well if you remove each hose from the manifolds and blow them out from there. Those hoses are easily unscrewed.

I suppose most of the system will be OK if you keep the cabin above 49F, but your hot water heater and its plumbing may be at risk if you don't keep it hot. I would recommend emptying the water heater, blowing out its plumbing from the manifold, and keep it closed off at the manifold for the duration of the season (I hate using antifreeze in the heater). A cracked fitting elsewhere is not too big of a deal, but a cracked water heater will set you back some.

Gary B
Bob MacWright
Posts: 15
Joined: Mon Aug 06, 2007 11:30 pm

Post by Bob MacWright »

Gary, I agree completely, it's not an all-winter solution. My concern was for nights that got down to 28-30 degrees, when the temps during the day are about 55 and the water temp is still over 50. By getting air into the lines, I'm less worried about a short-term freeze - especially for the cockpit shower lines, which are the most exposed. I keep the cabin over 36 with two electric heaters on thermostats, so whatever water flowed back to the low ends of the lines would be OK. This let me keep the boat in the water for about 3 weeks longer than I had originally planned. I got a few good sails in, but got a lot of projects done, putting the boat in great shape for spring.

Last weekend, i finally gave up, and got antifreeze into everything, and got the sails off. This Sat. I'll run it over to the marina for haul out, then start dreaming about next season!
EvenKeel
Posts: 33
Joined: Tue Mar 27, 2007 3:06 pm
Location: Carlisle, PA (slip-Herrington Hrbr, MD)

Post by EvenKeel »

Ahh, I see your point.

Mine got hauled this week, just before the snow hit in the mid atlantic. Wish I could have left it in all winter, but living 2.5 hrs away I won't be able to check on it enough.

I did mention that I drained the water heater. That was one of the least fun jobs I've encountered on the boat.
Pgtjs
Posts: 80
Joined: Tue Feb 07, 2006 2:13 am
Location: Blaine WA

Re: Stretch the season without worrying your pipes will freeze

Post by Pgtjs »

This is a question for Gary B and interested others, with regard to emptying the Water Heater. What do you mean by blowing it out at the manifold? And then shutting it off at the manifold? I can not even get into the space down beside the water heater - my size and aged body does not contort like it used to and I dont know of any midgets around here. Using the photo of the "front" panel controls for the water heater found elsewhere in annual maintenance list, there is a shutoff knob on one side and a "T and P" valve on the other. Do you mean that I should somehow just turn the two valves and let it drain into the bilge? Will this create an airlock when I go to restart it in the spring?

Further, I live in an area (northern Washington state) where we get some but very limited below freezing periods so most of us leave our boats in the (sea)water over the winter. I have already emptied the two main water tanks. If I take the boat out for a "run" using the diesel, will the engine heating damage the water heater if it is also empty? Perhaps I have to leave some water in the main tanks as well? Does the water heater drain back into the rear water tank or does it empty when you turn the hot water faucets on with no water in the main tanks? I have wondered if I leave the water pressure switch off but the faucets open, then will that suffice to prevent freeze damage to the fittings. I leave a couple of Westmarine heaters on in the boat all winter so the interior stays "warm" except for when we have extended power failures (3 days) which seems to happen every year or two. Perhaps I should just leave the Water Heater switched on when under shore power for the entire winter?

BTW, who ever thought this was a good place to put the water heater surely needs to be made aware that it is a poor choice for creaky old guys like me - as well it represents weight in the stern which is never desirable. One would have thought that the large starboard lazarette would have been much better, especially as the tank could be located below the water line.
Geoff.S., Semiahmoo, WA.
lyle
Posts: 45
Joined: Mon Aug 13, 2007 8:22 am

Re: Stretch the season without worrying your pipes will freeze

Post by lyle »

Hi Geoff, I keep my 350 just north of you in Vancouver, BC. I have never drained the hot water tank in the winter (or the water tanks for that matter) and like you, I keep some heat on the boat in the winter with a portable heater. If you are worried about freezing you could add RV system antifreeze to your water tank which is designed for potable water systems and is non-toxic. I don't - only because I use the boat in the winter and find it a pain to drain the water system and flush it every time I want to use the boat. I do leave the potable water system unpressurized and leave all the taps open. My boat is also tied up right beside my house so it is pretty easy to keep an eye on things when the temperature drops but I have done this for several years without a problem. As to running the engine with the hot water tank drained - I can't see it hurting anything. The engine coolant circulates through a jacketed seperate circuit which is like a heating coil within your hot water tank. That engine cooling hot water then heats the potable water in your tank but only through the heat exchange that takes place. Your engine cooling water temperature does not get above approximately 175 degrees F which should not be hot enough to damage anything in the hot water tank. With the climate we have here, it is very rare to have extended freezing temperatures - it does happen every few years though.
Lyle Hanna
"Serenity"
Hull #363
Last edited by lyle on Tue Oct 28, 2008 10:03 pm, edited 1 time in total.
Pgtjs
Posts: 80
Joined: Tue Feb 07, 2006 2:13 am
Location: Blaine WA

Re: Stretch the season without worrying your pipes will freeze

Post by Pgtjs »

Hi there Lyle, Thank you for your prompt reply. I think I will proceed exactly as you have. This year I will be away for 3-4 months so the boat will not be used periodically as it has in past winters. Still, with cabin heaters on and leaving the water heater on, it should not be a problem. Yesterday I lifted the board on top of the water tank on the starboard side of the rear cabin and noticed that the water hoses to the heater pass under the aft rear cabin bulkhead so some heat escapes to the rear lazarette after all. Too bad there is not a temp. adjustment dial for the water heater. Again, thanks for your input. By the way, I belong to the Gulf Yacht Club in up in Vancouver - sailors only including many off shore folks, many decades old, meets monthly, no racing, perhaps you might be interested in them - if so, contact me for details. Thanks, Geoff. Taeko 1V C350 # 392.
Geoff.S., Semiahmoo, WA.
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