Heater

[bottomlesspit]

Hi. When I purchased my boat, (Sealine motor cruiser) there was a 240v Greenhouse heater on board, and I have noticed a number of people comment on having these in engine bay. I have never used one previously, ( or needed) on yachts I have owned, Are motor boats particularly vulnerable to the cold, is this something I should be using during the winter? TIA

 

[fredrussell]

Do you mean the tube heater type? I think many people on here use them over winter to keep the damp at bay in boat and (if placed in engine bay) stop the engine freezing - though I would have thought you would be well advised to ‘winterise’ your engine rather than rely on a heater (which may fail).

 

[PaulRainbow]

Hi. When I purchased my boat, (Sealine motor cruiser) there was a 240v Greenhouse heater on board, and I have noticed a number of people comment on having these in engine bay. I have never used one previously, ( or needed) on yachts I have owned, Are motor boats particularly vulnerable to the cold, is this something I should be using during the winter? TIA

Unless you keep your boat in somewhere extremely cold it's a waste of money. The engine should be full of 50% antifreeze, if that freezes we're heading into another ice age.

It is worth switching the water pump off and opening the taps, just in case.

 

[PaulRainbow]

Do you mean the tube heater type? I think many people on here use them over winter to keep the damp at bay in boat and (if placed in engine bay) stop the engine freezing - though I would have thought you would be well advised to ‘winterise’ your engine rather than rely on a heater (which may fail).

Sorry Fred, but i've never winterised a fresh water cooled engine, it's full of 50% antifreeze.

Does anyone put tube heaters under the bonnet of their car, which will get even colder than the engine space on most boats.

 

[fredrussell]

Fair enough, but aren’t you meant to winterise a raw water cooled engine?
Funnily enough, I’ve just acquired a tube heater for my engine bay. It’s a freshwater cooled engine but it’s 30 years old and a bit rusty here and there and I’m hoping to keep the moisture off. The way I see it, dampest part of my boat in winter is the engine bay (big cold lump of iron = condensation), so a small tube heater in there should keep it at bay.

 

[PaulRainbow]

Fair enough, but aren’t you meant to winterise a raw water cooled engine?

I think it's considered good practice to run some fresh water/coolant through a raw water cooled engine.

 

[NBs]

If the sea does not freeze over, the engine and feed-throughs will not freeze. Experience with an air temperature of around -10°C and a machine room temperature of +°C.

In addition, salt water does not freeze at the same temperature as fresh water.

 

[wonkywinch]

Average sea temperatures around the UK don't generally drop below 6/7 degrees so leaving the boat in the water provides it with some protection against freezing.

 

[fredrussell]

Are we all assuming OP’s boat is left afloat all winter then?
I think another bonus, for me at least, of a tube heater in engine bay through winter is keeping a 30 year old engine wiring loom as dry as possible, though obviously I accept on a newer engine this is less of an issue.

 

[Graham376]

If the sea does not freeze over, the engine and feed-throughs will not freeze. Experience with an air temperature of around -10°C and a machine room temperature of +°C.

In addition, salt water does not freeze at the same temperature as fresh water.

We had the domestic fresh water system freeze hard enough to burst the galley tap one winter, afloat N Wales, sea didn't freeze. Raw water cooled engine was OK.

 

[russ]

Hi. When I purchased my boat, (Sealine motor cruiser) there was a 240v Greenhouse heater on board, and I have noticed a number of people comment on having these in engine bay. I have never used one previously, ( or needed) on yachts I have owned, Are motor boats particularly vulnerable to the cold, is this something I should be using during the winter? TIA

FYI therer's a sealineforum.co.uk for further info or questions you may have about your make of boat.

 

[Plum]

Hi. When I purchased my boat, (Sealine motor cruiser) there was a 240v Greenhouse heater on board, and I have noticed a number of people comment on having these in engine bay. I have never used one previously, ( or needed) on yachts I have owned, Are motor boats particularly vulnerable to the cold, is this something I should be using during the winter? TIA

Motorboats are no more vulnerable than sailboats and needing a heater on board will depend on typical winter temperatures where you are and whether your boat stays in the water or not. In over 45 years of owning and maintaining marine diesel engines I have never had a heater on board when I am not on board and have never winterised an indirectly cooled engine and never had a resulting problem (UK east coast).

 

[Dockhead]

Sorry Fred, but i've never winterised a fresh water cooled engine, it's full of 50% antifreeze.

Does anyone put tube heaters under the bonnet of their car, which will get even colder than the engine space on most boats.

Cars don't have raw water circuits.

Obviously you've never winterized a yacht.

It has nothing to do with the fresh water circuit. You run glycol through the raw water circuit.

The consequences of not doing it can be dire, if it gets cold enough.

I've done it only once on the South Coast of England -- one winter with the boat on the hard.

But overwintering in Denmark, in the water, I generally kept a tube heater going in the engine room. Because of the RAW WATER SIDE, not the fresh water side.

 

[Dockhead]

Average sea temperatures around the UK don't generally drop below 6/7 degrees so leaving the boat in the water provides it with some protection against freezing.

All hail the Gulf Stream.

Record low sea temp in Cowes (my home port) was 4. It's very unlikely to have a freezing problem if you're in the water, at least on the South coast, but it's worth worrying about on the hard, if the winter's cold.

 

[PaulRainbow]

Cars don't have raw water circuits.

Obviously you've never winterized a yacht.

It has nothing to do with the fresh water circuit. You run glycol through the raw water circuit.

The consequences of not doing it can be dire, if it gets cold enough.

I've done it only once on the South Coast of England -- one winter with the boat on the hard.

But overwintering in Denmark, in the water, I generally kept a tube heater going in the engine room. Because of the RAW WATER SIDE, not the fresh water side.

I said "Unless you keep your boat in somewhere extremely cold it's a waste of money"

With reference to raw water cooled engine i said "I think it's considered good practice to run some fresh water/coolant through a raw water cooled engine."

So thanks, but i'm fully aware of how to winterise an engine.

The OP isn't in Denmark, he keeps his boat in a marina on the East Coast of the UK.

 

[billskip]

All hail the Gulf Stream.

Friend of mine would have welcomed that, sadly it doesn't flow up the Thames to Shepperton, where his boat went down due to freezing and fracturing the raw water inlet.

 

[Refueler]

All hail the Gulf Stream.

Record low sea temp in Cowes (my home port) was 4. It's very unlikely to have a freezing problem if you're in the water, at least on the South coast, but it's worth worrying about on the hard, if the winter's cold.

A few years back - my Brother died in Southsea when the weather dipped to -10C .... he was an alcoholic and ended up frozen to the apartment floor havng not switched on the heating.

With respect to boats ... when I used to lift out for winter in UK ... I left raw water intake seavalve open and the water drained out ... with the Heat Exchanger 4-99 I had - that was good enough due to the Anti-Freeze solution in the erngine itself. But the replacement 4-107 was raw water only and I did same ... one winter - the plugs in the block blew and I was lucky that was the only result.

IMHO - its all well and good saying Uk waters stay unfrozen - a combination of salinity and Gulf Stream .. but for the sake of running a few litres of AF through - isn't the peace of mind worth it ?

I know I experience generally colder winters than many of you ... but still the principle is same ...

I run up engine to operating temp ... close seacock and open up filter box .. pour in AF while engine running .... my 4-107 - I usually put about 8 - 10 litres through it ... watching exhaust for when its full AF colour.
When done on shore - I use a garden hose into a funnel for water while engine temp is brought up ..... once at temp stop engine .. then get a large bore plastic drain pipe propped up to transom for exhaust to direct through ... other end of pipe into a large bucket / bin ... start engine - p[our in AF ...
This then lets you see the state of the AF when it comes out and collects ... you then see that AF has a good action of cleaning !! Also allows you to avoid environmental damage.

 

[AntarcticPilot]

Average sea temperatures around the UK don't generally drop below 6/7 degrees so leaving the boat in the water provides it with some protection against freezing.

View attachment 203243

Don't be too sure - the biggest mosquitoes I've ever seen were in Svalbard - and they could bite through a shirt! Admittedly in summer, but average temperatures were about 5°C

 

[oldgit]

Ere we go again.
Thames freshwater marina.
B1 of the MoBo parish kept a boat in PH or Bray and being bit of a techno-nerd installed a couple of temperature sensors which could record temperature variations over a few days.
One was located in the bilge and the other somewhere externally to record air temps.
In a graph posted online, which might still be around somewhere, on the final day of the experiment , the water in the marina had a light thin layer of ice on the surface of the static water within the marina.
The air temperature had fallen below 0 C but the temp in the bilge had never fallen below 6C or 7C.
However he always kept a tube heater in the bilge.

Have known water in the cast Iron risers of a MoBo to freeze and to crack as a result , requiring replacement. The boat was ashore for the winter.

In my tidal mooring location, salt/brackish and moving from 1-3 knots,the temps would need to go well below freezing to worry much about engine damage in salt raw water and 50% A/F in the block.
Have no problems using a tube heater in the engine compartment which also hold both my freshwater tanks.
A boat not far away had to have the sink tap replaced when it froze and split some time ago.
For those of us with boats kept close to home , a quick job just to nip down to the boat (again) just to check stuff and turn on the tube.

 

[AntarcticPilot]

Ere we go again.
Thames freshwater marina.
B1 of the MoBo parish kept a boat in PH or Bray and being bit of a techno-nerd installed a couple of temperature sensors which could record temperature variations over a few days.
One was located in the bilge and the other somewhere externally to record air temps.
In a graph posted online, which might still be around somewhere, on the final day of the experiment , the water in the marina had a light thin layer of ice on the surface of the static water within the marina.
The air temperature had fallen below 0 C but the temp in the bilge had never fallen below 6C or 7C.
However he always kept a tube heater in the bilge.

Have known water in the cast Iron risers of a MoBo to freeze and to crack as a result , requiring replacement. The boat was ashore for the winter.

In my tidal mooring location, salt/brackish and moving from 1-3 knots,the temps would need to go well below freezing to worry much about engine damage in salt raw water and 50% A/F in the block.
Have no problems using a tube heater in the engine compartment which also hold both my freshwater tanks.
A boat not far away had to have the sink tap replaced when it froze and split some time ago.
For those of us with boats kept close to home , a quick job just to nip down to the boat (again) just to check stuff and turn on the tube.

The only time I've had fresh water freeze on my boat was when she was out of the water. As noted, a boat that is afloat MUST stay at or above the freezing point of water, and as others have noted, the bulk temperature of seawater rarely drops as far as freezing point. However, air temperatures, even in the UK, can easily drop well below zero (the record is almost -30°C!) and a boat that is NOT in contact with water can easily experience very low temperatures. Personally I feel my boat is safer in the water during the winter!