Unusual incident

[Witzend]

I have not filled my water tank yet, since winterization.
I'm on my mooring and wanted to run the engine to charge the bat.
It ran hour or so, and I shut it off. I then heard water running, so I started to investigate. The head sink was overflowing on the floor. I had left the water faucets on and the drain cock was closed from winterization.
Hot pink water was coming out of the faucet! When I winterized, I drained the main and HW tank, bypassed it and ran polypropylene glycol through the system and out each faucet. I had then removed the shunt and replaced the lines so I would not forget next spring.
Running the engine had apparently expanded the remaining polypropylene glycol in the system and forced it out the open sink faucet. I was surprised about the volume, ~1.5 gal. At first I thought that maybe the heat exchanger had ruptured and what was coming out was ethylene glycol, but no loss of engine coolant put a relieved rest to that theory. Anyway seems like anything can happen on a boat.

 

[Stu Jackson]

At first I thought that maybe the heat exchanger had ruptured and what was coming out was ethylene glycol, but no loss of engine coolant put a relieved rest to that theory. Anyway seems like anything can happen on a boat.

That would have been truly strange and unusual, because not only would that have had to happen, but the HX inside the water heater would have had to rupture too, at the same time, for that to have happened., Right?

Glad things worked out.

 

[kloudie1]

Likely that there was a big air bubble in teh hot water tank. The air/water vapor and stuff expanded when hot and pushed teh liquid in teh pipe out the open faucet.

 

[Witzend]

Yes, that is what I think, but what I find unusual is the volume of fluid that came out.
It filled up the sink and ran 1/2" on the floor. Seems a bit much? I did notice that the drain for the HWH is not really at the bottom, so that may be where the water was stored and then pushed out. This would not have had any glycol in it though, cause I bypassed when winterizing, so at least at the end of the stream it would have run clear, and it wasn't. The other factor is that it was winterized on the hard and now it is in the water. The angle of the boat is now different.

 

[Peggie Hall HeadMistress]

Oh dear...

He said he bypassed the water heater when he winterized.

But then he said he undid the bypass after he winterized...which makes NO sense, 'cuz the whole idea of draining and by-passing the water heater is to keep anitfreeze OUT of it!

So what you did was UNDO what you tried to avoid by bypassing the water heater--you dumped a whole bunch of antifreeze into the water heater that's gonna take a WHOLE LOT of flushing to get rid of it! (And if that much antifreeze ended up in it, you didn't do that great a job of winterizing the rest of the system either).

When you winterize it this time, leave the bypass in place until AFTER you've recommissioned the system in the spring!

What is it that compels people to keep trying to reinvent the wheel?

 

[Witzend]

You mis-understood me.
I put the bypass in, winterized the system...pumped the glycol thru the system, and only after the systems had no pressure left with all the faucets open and some weeks later I took the shunt out, so there should have been nothing left but static glycol in the lines. No one is re-inventing anything here!

 

[Peggie Hall HeadMistress]

Shoulda left it in till after you recommissioned

Otherwise, you can't recommission without putting antifreeze into the water heater. However, since the inlet on the water tank is at the bottom, I suspect gravity put it in there a lot sooner.

 

[Witzend]

On my HWH the drain is not completely at the bottom, it comes out the port side. If when on the hard the boat was leaning, and now that I think of it was leaning a little to starboard then it would not have drained completely. Still the volume has me baffled? Maybe I only thought I drained it and something plugged the drain hole and there was a lot more water in it. The pink color was light and very washed out, water was hot though. I get your point that the system needs to be flushed out prior to taking the shunt out.

 

[Banooma]

At the risk of sounding completely unknowledgable on this topic, what is the negative impact of winterizing with non-toxic pink RV antifreeze in a hot water heater?

 

[Don S/V ILLusion]

At the risk of sounding completely unknowledgable on this topic, what is the negative impact of winterizing with non-toxic pink RV antifreeze in a hot water heater?

None really, other than wasting (the cost of) 5 gallons of antifreeze when you could have simply drained the tank.

I'm not sure here but I infer, maybe incorrectly, that some believe it essential to completely drain the heater - a small amount of water remaining (inevitable regardless of how thoroughly one tries to void the tank) has sufficient room for expansion such that no damage would occur.

 

[Witzend]

Absolutely, Don a little left is no problem. Now if it were at the level of the heat exchanger (coil with fins, some one pipe in here, not sure of the design?), and froze, that may cause a problem.
Also not sure why it is a problem for Polypropylene Glycol to be in the HWH either. It is after all potable that is why it is used, and who is going to drink hot water from a boat anyway. Just a mystery as to the volume of water that was displaced as a result of running the engine.

 

[Peggie Hall HeadMistress]

If antifreeze isn't flushed out of the water heater...

it can damage the heating element when it's being used to heat water. Won't hurt anything if only the heat exchanger is used...just don't turn on the AC breaker for the water heater while it's in there.

It also smells bad in addition to tasting bad.

 

[Dan]

None really, other than wasting (the cost of) 5 gallons of antifreeze when you could have simply drained the tank.

On a (semi?) related topic, why use antifreeze at all? Could the lines simply be cleared of all standing water with a wet vac?

Not to worry....I didn't test this theory. I bypassed the water heater, emptied it and filled my system with pink stuff.

 

[Don S/V ILLusion]

On a (semi?) related topic, why use antifreeze at all? Could the lines simply be cleared of all standing water with a wet vac?

Not to worry....I didn't test this theory. I bypassed the water heater, emptied it and filled my system with pink stuff.

It is sometimes difficult to verify there are no low spots in the pipe runs throughout a boat in which water can lay even after you try vacuuming out the lines. On a boat without much plumbing and if you can see all of it, vacuuming might be a safe way to go but I'd wonder why take the chance given the small amount of antifreeze necessary to ensure the lines are purged of water.

I too by-pass the heater and fill the rest with antifreeze.

When I winterize the lines, 2 heads, 3 sinks, water heater (by-passed), A/C, transom shower and 4 tanks, it takes 2.5 gal of antifreeze - not worth the time to try to purge everything.

 

[Witzend]

I highly doubt that Polypropylene Glycol would have an appreciable effect on any electric heating element, certainly not at these temperatures and concentrations, it is a pretty non-reactive compound. There are (2) types of heating elements used, not sure which one is more prevalent in the marine HWH industry: Incoloy, these are generally a high-grade stainless steel, and Non-incoloy, that are nickel plated copper, neither will react with Polypropylene Glycol.
This is why you can drink it and not get sick, it does not metabolize, unlike ethylene glycol which metabolizes and becomes poisonous. The only danger here to your element is accidentally energizing it dry. I tape the switch off when winterized.