Sunday, 24 November 2013

Preventing the boat freezing inside

One of the difficulties with a boat moored over 100 miles away is keeping an eye on the temperature inside. What I don't want is water freezing in the pipes, taps or shower mixer.

This will be the first winter I've had to worry about this. During the last cold spell Ally and Ben were living aboard full time, and therefore keeping the place warm. Now they are staying with friends until they can move in to their house. Meanwhile half their stuff is still on board.

Some people, I know, remove the shower mixer altogether. Draining the domestic water seems the minimum one should do. I have not done this before - do I simply turn on all the taps so as to completely empty the water tank? Or is there a way to empty the pipework while still keeping water in the tank?

And there are two other water systems on the boat: the engine coolant and the central heating water.

In the nearly two years I've had the boat I have never had to top up the engine coolant, so I assume the antifreeze in it is the right strength and effective. (It's probably a bad thing to assume anything - should I drain and replace the coolant?)

And what about the central heating? Should I drain this or top up the header tank with antifreeze? And is it all right to use the same antifreeze as I would put in the engine?

Or perhaps I needn't bother with any of this. As I'm paying for a marina mooring, with electric hook-up, I could put an electric fan heater in the boat on a minimum thermostat setting. In fact, I have already done this. I have positioned it on the floor in the saloon, pointing towards the galley and bathroom. Will this be sufficient? Will the electricity run out? Would this be a complete waste of money as the boat could freeze up anyway?

Has anyone done the electric heater thing in their boat, and does it work?

Will I ask any more questions?

The photo, by the way, is one from the archive: 16th February 2009, Shadow on the GU Leicester Section just north of Crick.


Nev Wells said...

Lol... that's a lot of questions.

We have been the victim of frost damage twice on Waterlily. Q have you plastic or copper ? Plastic fares much better.

Engine - buy a cheap tester from halfords and check the level of protection. As the engine is below the water line it does not get too cold, used to drop an old coat over the top.

Domestic CH - use the same tester and top it up via the water tank and run it, best to not add neat antifreeze.

We just unscrewed the shower pipe, other alternative, with the taps open blow down the pipe to clear any water from the mixer unit.

we never drained the hot water tank, it was very well insulated , surrounded by loft insulation under the bed. We left the cold water tank half full to allow for expansion if it froze.

We left all the taps open to allow expansion but still the frost got to the copper where there was water trapped. I replaced it with plastic and insulated the pipe with simple pipe insulation.

I think you electric will soon run out with a fan - what about a greenhouse heater on very low.... best option it to live aboard and have the fire on. In the worst of winter I have driven over to the boat and lit a fire.

Good luck

Adam said...

We left an electric heater on one wonter -- it cost a lot, and made no noticeable difference.

We leave the water tank half full, but turn off the stockcock between the tank and the water pump. Then turn all the taps on to drain water from the pipes. Turn the water pump off once it's done that. Leave all the taps open to allow for freezing expansion.

Having lost one shower mixer bar, I now remove it, dry it as much as possible, and leave it in a drawer wrapped in the spare duvet.

The hot water tank is well lagged and inside, so we never bother draining it down. People with semi-trads or cruisers who have the calorifier in the engine bay are more at risk.

We don't do any more, partly because we like to use the boat during the winter!

Anonymous said...

Use green heater (tubular) 3ft in engine bay, and small oil filler radiator in bedroom, and living are and another small green house heater in bathroom

Halfie said...

Thanks all for your replies.

Nev, the pipes are copper. Good idea about blowing the water out of the shower pipework. I guess it's all right to use "engine" antifreeze in the central heating then. Living aboard is not an option for us at the moment - nor is a 200 mile round trip to light a fire!

Adam, if I turn off the stopcock at the tank outlet, how is the pump able to push water remaining in the pipework out of the taps? Would I also need to crack open a joint to let air in?

Anonymous, that sounds like a lot of heating, but it also sounds like the only way to be absolutely sure that it won't freeze without draining down.