Winterising the Fresh water system

[KevO]

Looking at the star brite engine and fresh water system antifreeze stuff, rather than drain the whole system down is it acceptable to just add the stuff to the fresh water tank and pull it through the whole system, including the calorifier?

 

[Tranona]

Would not bother where you are located. Highly unlikely it will ever get cold enough inside the boat to even form a film of ice let alone freeze. However if you have a transom shower, best to remove this or isolate it as wind chill can freeze the small amount of water in the head.

 

[KevO]

Yeah… knowing my luck it will be the coldest winter since Pontious was a trainee pilot and our new calorifier will go for a burton ?

 

[NormanS]

Small volumes of water, in pipework for example, can freeze quite easily. Larger volumes in tanks etc, are much less susceptible. I drain all my pipework, but leave the tanks not quite full. I would imagine that it's milder where you are.

 

[johnalison]

I follow the instructions and also drain the f/w pump if I am ashore, but if afloat seldom bother unless a hard freeze is forecast.

 

[KevO]

I’m on the hard as of yestertag, not afloat

 

[MikeBz]

The instructions for that stuff say not to add water, so I imagine you'd need quite a lot of it to pull it all of the way through the freshwater system including the calorifier.

 

[RJJ]

Looking at the star brite engine and fresh water system antifreeze stuff, rather than drain the whole system down is it acceptable to just add the stuff to the fresh water tank and pull it through the whole system, including the calorifier?

It won't hurt, it will just take rather a lot of the 5l bottles to fill the calorifier and the pump/pipes.

Hence what's recommended is drain the calorifier and bypass it.

If you bother at all. Recent poll on here (by me) suggests majority in southern UK don't bother, in or out of the water. Although as mentioned there could be points of vulnerability like your transom shower.

 

[KevO]

Real question was, can I run the star brite stuff through and leave it in the calorifier? The instructions for the engine say undiluted, for the FW system I think it is diluted. Can’t find the destructions online from my phone and don’t have the bottle to hand.

 

[Tranona]

Think you are getting confused here. There are 2 broad types of antifreeze mixtures - one for the engine cooling system which also circulates through the coil in the calorifier. You will already have this in your engine. The second is for protecting freshwater systems mainly for RVs and mainly in very cold climates. Never heard of anybody using this in the UK, although no doubt some may do in the more extreme northern parts of the UK. Totally unnecessary in boats in the less cold parts of the UK. Not a chance your calorifier will come to any harm even if you don't drain it of fresh water. The vulnerable parts of the freshwater system as already suggested are pipes, pumps, shower heads when the retained quantity of water is small and there is no insulation - exactly the opposite of a calorifier! Even then the temperature inside the boat is unlikely ever to fall below freezing - it is the wind chill factor that mostly causes freezing of external taps, pipes etc .

If you are still worried then drain the freshwater out of the calorifier and the pipes then leave the taps open

 

[Ammonite]

I drain the tanks as much as I can, without resorting to blowing air through them or taking the system apart. In other words until the taps are spluttering and then I add a bottle of potable antifreeze (4L?) to the tank and run the hot and cold taps taps and shower until they come through bright pink. I'm based in Hampshire and started doing this after two flexible 75L tanks froze solid and the water pump blew apart, so it does get cold enough on occasions (when on the hard)

 

[KevO]

I drain the tanks as much I can, without resorting to blowing air through them or taking the system apart. In other words until the taps are spluttering and then I add a bottle of potable antifreeze (4L?) to the tank and run the hot and cold taps taps and shower until they come through bright pink. I'm based in Hampshire and started doing this after two flexible 75L tanks froze solid and the water pump blew apart, so it does get cold enough on occasions (when on the hard)

Exactly my reason for the question…

 

[QBhoy]

Is it not just as easy to drain the tank, drain hot water tank and open up the pump intake to drain too ?
as for the advice earlier, not to bother doing anything…jeez…scary advice that. Especially ashore.

 

[MikeBz]

Real question was, can I run the star brite stuff through and leave it in the calorifier? The instructions for the engine say undiluted, for the FW system I think it is diluted. Can’t find the destructions online from my phone and don’t have the bottle to hand.

From StarBrite’s website:

Star brite® -50°F (-46°C) Non-Toxic Antifreeze provides excellent cold weather and corrosion protection for drinking water systems and all engines. Its premium additive package prevents corrosion of aluminum, copper, brass and solder, but will not harm rubber, seals or hose materials. The 3X-dyed bright pink color provides excellent blow-through visibility. Formulated with virgin, non-toxic USP-grade ingredients. It contains no alcohols. This product is ready-to-use; do not dilute it.

I note that prices vary wildly from supplier to supplier but some are out of stock.

 

[Tranona]

Is it not just as easy to drain the tank, drain hot water tank and open up the pump intake to drain too ?
as for the advice earlier, not to bother doing anything…jeez…scary advice that. Especially ashore.

Been doing it (nothing that is!) in Poole for over 40 years. Mostly afloat, but also ashore. Only problem is the burst shower head I referred to earlier.

 

[Momac]

I have certainly had a couple of losses due to freezing plumbing inside the boat and with the boat in the water ,
So draining as much water of as possible is good
I have a small frost protection heater which I place near the calorifier - assuming you have shore power .
Like this

Or use a tube heater

 

[QBhoy]

Been doing it (nothing that is!) in Poole for over 40 years. Mostly afloat, but also ashore. Only problem is the burst shower head I referred to earlier.

Lucky fella so far, sounds like. Dare say that your climate might be less of a risk than others too, perhaps. It’s a must up here anyway.

 

[jdc]

We're also in Falmouth (Mylor). Here is the ambient temperature aboard (no heating) over the last two winters; last winter it only just got down to 0, and winter before there were only one or two days. It never got less than -1.4°C.


We drain the tanks as best we can, and empty the water as best we can, but don't fill with antifreeze. We have broken a shower head, but that was because I left it undrained. So I tend to agree with Tranona.

 

[ChromeDome]

Before lifting I empty the holding tank.

When on the hard I drain coolant from the engine circuits and store use it to run through the sea-water strainer. It takes 10 litres per engine for the exhaust to change colour, showing that the coolant got through.

Then drain the freshwater system by opening all taps and leave them open/remove shower heads and pour a couple of litres of screenwash antifreeze into the toilet & holding tank (cheaper, less discolouration) .

Used the Starbrite stuff once but didn't find it any better. It took a lot of flushing to get it out before next season.

The boat is over-wintering on the hard in Scandinavia, apart from a blown shower head on the swimming platform some years ago, I never had an issue.

The guy next to me on the hard (Regal 258 Commodore) uses the same method but adds a no-taste, no-colour antifreeze to the freshwater circuit: The cheapest available Vodka!

 

[Tranona]

We're also in Falmouth (Mylor). Here is the ambient temperature aboard (no heating) over the last two winters; last winter it only just got down to 0, and winter before there were only one or two days. It never got less than -1.4°C.
View attachment 145088

We drain the tanks as best we can, and empty the water as best we can, but don't fill with antifreeze. We have broken a shower head, but that was because I left it undrained. So I tend to agree with Tranona.

Good to have some real world data. Would be interesting to also have data on water temperature in the tanks, particularly the calorifier with its thick insulation. A few days below zero is unlikely to lower the water temperature much. Transom mounted shower heads are common bailures because of being exposed to cold winds and having very small volumes of trapped water. The moulding seams fracture.