Mariner Seville 37/AKA Helmsman 38 tricks to drain hot water heater

Have the Seaward 20 gallon hot water heater. Are there any tricks to drain hot water tank for winter? Last year it seemed we only had 3 or 4 gallons to drain. This year, more like 18 after running the pump to the point of sputtering faucets. Even with the drain valve open all the way, it seemed like it trickles out very slowly. VERY SLOWLY! I put a shop vac next to it, leaving a tiny gap for air, and it really speeded it up, but it's only a 3 gallon one, so would close the valve after the 3 gallons, empty the vac and repeat until done. and that meant considerable time wedged in the cramped space. I hooked a short bit of hose to see if it would drain out (didn't) but didn't try it with the vacuum. Any short cuts or tricks to make it easier next year?

Open the pressure/temperature relief valve while you drain so it can draw air in at the same time. I bypass the hot water tank supply and return so I don't have to introduce antifreeze into it. Once the tank is drained below the drain valve you don't need to worry about any water left in the tank as it will simply expand in the tank when it freezes.

James

Thanks. I had wondered about that but was worried if I opened it, it might not close. it looked like a little toggle. do you just lift it?

Yes, lift it 90° and it will stay open.

James

I used to just drain the WH into the bilge but that left water the bilge pumps wouldn't remove and required a wet/dry shop vac to dry up before winterizing. I have an otherwise dry bilge and fussy about any standing water.

I use compressed air to blow out my water systems before introducing pink AF. I connect a hose to my water heater drain and run it outside. I then use compressed air to blow out the tank. I've tested this by checking the completeness of drain by removing the hose with the drain still open and no water remaining. I then switch the WH bypass valves before introducing AF.

Bacchus said:

I used to just drain the WH into the bilge but that left water the bilge pumps wouldn't remove and required a wet/dry shop vac to dry up before winterizing. I have an otherwise dry bilge and fussy about any standing water.

I use compressed air to blow out my water systems before introducing pink AF. I connect a hose to my water heater drain and run it outside. I then use compressed air to blow out the tank. I've tested this by checking the completeness of drain by removing the hose with the drain still open and no water remaining. I then switch the WH bypass valves before introducing AF.

Click to expand...

We used compressed air to clear all the water lines both before we put in AF and after, hoping to get most of the AF out to reduce taste, but have not used compressed air to make sure the water tank was empty, figuring that when there was no more water coming out f the little white drain of the WH it should be empty. Where do you attach the compressed air to get it to go onto the tank?

We also blow out the raw water washdown and after running AF through the toilets (3 flushes each) I take a bucket under the macerator discharge and briefly turn on the macerator, so get a bit of RF in that pump. PNW winters on the coast tend to be not as harsh as were we live, but we had an interesting split in the stbd water tank on/off valve. I had thought I got most of the water out of the tanks last year, but apparently didn't, so this year vacuumed out those as well.

I also like a dry bilge and this year when it was quite warm noticed I was getting water in the bilge. Traced it back to under the floor bulkhead drain under the fridge. Some of the copper wire at the compressor wasn't insulated, so I did that and put a towel under it to catch that little bit of water and the bilge stayed dry the rest of the summer. Seems to be alot more "always somethings" with a trawler. Don't remember having more than a rare issue on my sailboats.

Using compressed air to blow out all the water lines eliminates the need for antifreeze 'cuz it's not freezing temperatures that cause damage...water expands about 10% when it freezes. That's what bursts hoses. No need for antifreeze in the tank 'cuz any water in the bottom of it has plenty of room to expand. Drain the water heater and bypass it (there are kits to do this.) If you put antifreeze in it, you'll have a hard time getting rid of the taste in hot water.

Flushing antifreeze down the toilet doesn't protect anything but the holding tank. To do it right, remove the toilet intake line from the thru-hull (close the seacock first!) and stick it in jug of antifreeze...then flush the toilet. That pulls antifreeze through the intake line, pump, and the channel in the rim of the bowl as well as the discharge line and holding tank.
If your toilet uses pressurized fresh water, you winterized it when you winterized the fresh water system so all you need to do is flush some antifreeze into the tank to protect the discharge line.

--Peggie

capran said:

We used compressed air to clear all the water lines both before we put in AF and after, hoping to get most of the AF out to reduce taste, but have not used compressed air to make sure the water tank was empty, figuring that when there was no more water coming out f the little white drain of the WH it should be empty. Where do you attach the compressed air to get it to go onto the tank?

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We also use compressed air to drain all the water lines and the water heater.

Our easiest "air" inlet is on our dockwater inlet line; just connect and blow. Open and close various drain valves (like the water heater drain) during the process. We also attach a garden hose to the water heater drain valve, to send the drainage overboard instead of just into the bilge.

I only put AF through the freshwater pump itself. Disconnect inlet and outlet fixtures, suck a quarter cup of pink, done. Minimal impact, no AF in tanks or lines, no aftertaste.

-Chris

On a side note, the Seaward Al tanks can often be short lived due to corrosion. Mine made it 8 years before the Al tank exterior started to weep brown sludge. When replacement time came (with a new glass line Torrid) draining the old Seaward was a pain. Upon removal the tank bottom was badly crudded up with Al sludge blocking the drain valve.

well, that's depressing! And just when I was starting to feel better about the switch from sail. I uess owning a trawler really is where the large annual expenses comes from.

HeadMistress said:

Using compressed air to blow out all the water lines eliminates the need for antifreeze 'cuz it's not freezing temperatures that cause damage...water expands about 10% when it freezes. That's what bursts hoses. No need for antifreeze in the tank 'cuz any water in the bottom of it has plenty of room to expand. Drain the water heater and bypass it (there are kits to do this.) If you put antifreeze in it, you'll have a hard time getting rid of the taste in hot water.

Flushing antifreeze down the toilet doesn't protect anything but the holding tank. To do it right, remove the toilet intake line from the thru-hull (close the seacock first!) and stick it in jug of antifreeze...then flush the toilet. That pulls antifreeze through the intake line, pump, and the channel in the rim of the bowl as well as the discharge line and holding tank.
If your toilet uses pressurized fresh water, you winterized it when you winterized the fresh water system so all you need to do is flush some antifreeze into the tank to protect the discharge line.

--Peggie

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my fear of compressed only would leave just enough water in some low spot to freeze. and that's depressing about the no benefit of the tiolet. I miss my old salt water raritan when I had access to everything. I don't even know who to access lines inside the fresh water flush toilet.

If you'd ever bothered to look at an exploded drawing and parts list of your toilet, you'd know that there are no water lines inside fresh water toilets...Turn off the fresh water pump at the breaker remove the intake line from the bowl and then flush the toilet to clear the rim of the bowl and the discharge line, which isn't part of the freshwater plumbing. If you've only been pouring antifreeze down your previous sea water toilet(s), you've been lucky never to have found a cracked bowl in the spring, because doing that doesn't get the antifreeze into the pump or the channel in the rim of the bowl.

--Peggie

with the Raritan sea water units I would close the input line (sea water) and pump RV fluid through pump which would fill the pump, and line toward the holding tank. Maybe I just got lucky, for 30 years. I had hoped when flushing the electric fresh water, with the line before the pump, that any lines that usually contain water would instead contain rv antifreeze. (I have been closing the empty water tank and removing the hose end at the tank, and putting the ose into a gallon of AF and when I flush the toilet, it would suck the RV AF instead of the usual water supply, into the system. When I was done with that process for both toilets, I put a bucket under the macerator discharge thru hull and briefly turn on the macerator, until seeing the pink RV AF come out. I was hoping that meant the RV made it through the toilet and into the holding tank, and then out via the macerator, so that it too had a little rv fluid in there. I have never seen a diagram of the toilet to track down the intake hose.

HeadMistress said:

If your toilet uses pressurized fresh water, you winterized it when you winterized the fresh water system so all you need to do is flush some antifreeze into the tank to protect the discharge line.

Click to expand...

Yeah, while we're pumping air through the whole freshwater system, flushing the toilets several times during all that clears the intake lines and the inlet holes around the rim... just another component of the freshwater system, easy with air, actually.

And as you say, some AF through the outlet... enough to pass through the vacuum generators and the hose to the holding tank.

-Chris

interesting. I only know that wife tried to flush once without the water turned on and it created a vacuum and would no longer flush. we poured a bunch of water into the bowl and got it to prime and started working again, so am a bit reluctant to try to flush while the compressor is blowing air. For the last two winters I had removed the hose coming out of the water tank, stuck it in a bottle of RV fluid and flushed the toilet. It takes about a half gallon per flush (3 flushes), and first mate could see bright pink RV AF flushing though, which I sincerely hope is protecting both the toilet and the lines to and from the toilet, as well as the holding tank and the line to the macerator (since I also ran that until pink came through, (and take that bucket and dump it in a near by outhouse that gets pumped out.)

capran said:

interesting. I only know that wife tried to flush once without the water turned on and it created a vacuum and would no longer flush. we poured a bunch of water into the bowl and got it to prime and started working again, so am a bit reluctant to try to flush while the compressor is blowing air.

Click to expand...

Not sure what you're describing, but I think usually the vacuum generator needs at least a small amount of liquid in the bowl to help create the seal where the flusher (?) opens. Easy enough to add a small amount of AF directly to the bowl for that... for a few more subsequent "flushes"... even while only compressed air is coming through the hole under the rim.

-Chris