Empty hot water tank for winter?

[nikvah]

Hi there,

as a newby to ownership I have winterised my boat by emptying the main water tank and running the hot-water tank/calorifier dry, leaving the taps open and disconnected the water pump. I visit the boat once a month to run the engine for an hour as I have been advised.

 

Should I have left water in the calorifier, as the engine heats this when it is running. Could the engine overheat?

 

Grateful for any advice.

[Ray T]

First part yes.

 

Second part, I empty the calorifier as well, have been for the past six years and never damaged the engine or calorifier yet! I even take the boat out for a 45 minute run and back on occasions.

 

Also if you have a water filter don't forget to empty that too. I didn't one year and had to buy a complete new filter.

 

Good idea to keep your batteries charged too.

Edited December 2, 2015 by Ray T

[Chewbacka]

Hi there,

as a newby to ownership I have winterised my boat by emptying the main water tank and running the hot-water tank/calorifier dry, leaving the taps open and disconnected the water pump. I visit the boat once a month to run the engine for an hour as I have been advised.

 

Should I have left water in the calorifier, as the engine heats this when it is running. Could the engine overheat?

 

Grateful for any advice.

Engine is cooled by the skin tank or raw water depending on your system. If you think about it, after a few hours cruising the hot water tank is at the same temp as the engine coolant and so stops 'cooling' the engine all without problems.

 

Added = Fixed a couple of typos

Edited December 2, 2015 by Chewbacka

[nikvah]

Thanks for the replies which make very good sense. I'll keep the caloifier empty and the batteries full.

[Boat&Bikes]

Thanks for the replies which make very good sense. I'll keep the caloifier empty and the batteries full.

Please excuse me if you already know, but did you actually drain the calorifier via drain point?

 

Ian.

[nikvah]

No, I just ran hot taps after bow water tank was empty. The calorifier is internal, under the bed. I assume that any residual water/ice just needs room to expand should there be a freeze severe enough to effect it.

[DHutch]

I leave the main tank, but drain all other plumbing including the hot water cyl.

 

 

Daniel

[Scholar Gypsy]

No, I just ran hot taps after bow water tank was empty. The calorifier is internal, under the bed. I assume that any residual water/ice just needs room to expand should there be a freeze severe enough to effect it.

 

There's another recent thread about draining calorifiers - http://www.canalworld.net/forums/index.php?showtopic=80690&hl=

 

In this context I think the main points are:

 

• you probably need to focus on draining all the pipes. Depending on your system this can be quite tricky as you may have a number of one-way valves, and more than one low point - sod's law tells you that the water will collect and then freeze at one of those low points. [Don't ask how I know this].

• draining the calorifier is not straightforward - opening the hot taps and blowing air through can't do it, as the hot water comes from the top of the calorifier - but as you say you don't need to get it all out to make sure it doesn't burst if it does freeze. You need to drain it from the cold water inlet (which is at the bottom) - see the other thread.
• emptying the cold water tank is not necessary - provided the isolator is very close to the tank

Edited December 3, 2015 by Scholar Gypsy

[ditchcrawler]

I leave the main tank, but drain all other plumbing including the hot water cyl.

 

 

Daniel

Same

[KenK]

I also empty the hot water tank but I do not have a drain point.

I made up a fitting using the correct size of pluming fitting for the pipework on top of the vertical cylinder and a Schrader valve from an old bike inner tube.

Break into the plumbing, fit my adaptor and pressurize the tank using an air pump with a hot tap open.

Gets rid of all the water in the tank and in the pipework.

 

Ken

[trackman]

See my comments on the other thread about Surecal calorifiers which have non return valves built into them on the cold water inlet.

 

They are almost impossible to drain in my experience!

[DHutch]

For years and years all we did was.

 

- Ensure water tank is fairly full, but has some air space.

- Open all taps, take off shower hose, and allow to drain to lowest level (bath taps, so knee hight)

- Hot water tank drains very slowly back into the bath via the nrv on the cold inlet.

- Isolate water tank valve, to retain tank water if plumbing fails.

 

We did about 22 years of that, without issue. But then above three four years ago in the bad winter we had some damage so made some changes, including fitting a pair of drain cocks to the end of the hot and cold water run in what would be the engine space on a modern boat. Hence now the drain down now includes opening these valves.

 

 

Daniel

[ditchcrawler]

 

Gets rid of all the water in the tank and in the pipework.

 

Ken

Are you sure

[KenK]

Are you sure

Yes because eventually the water stops flowing and air comes out of the taps instead.

 

Ken

[ditchcrawler]

Yes because eventually the water stops flowing and air comes out of the taps instead.

 

Ken

Well if its like mine that is due to the take off being at the top of the cylinder and the cylinder is still full to within an inch of the top.

[KenK]

Well if its like mine that is due to the take off being at the top of the cylinder and the cylinder is still full to within an inch of the top.

I remove the PRV, connect the fitting and pressurise the top of the tank, water comes out of the cold tap. When the cylinder is empty I close all the taps pump it up to about ten pounds and open a hot tap, repeat for each tap. That empties the hot pipework.

 

Ken