Sterilising water tank / calorifier

[mil1194]

I’m spending more time in my boat and have ended up with an eye infection. This could be complete coincidence but now that it’s crossed my mind I want to sterilise my tanks. The obvious(?) method would be to run them dry (hot and cold) and then put some/enough cold water and add ‘cleanser’. Then run the pumps to fill the calorifier etc. Does this sound like the best method or do I need to fill the cold water tank as well in case anything is stuck to the sides?
I’ve 1000l stainless tank which takes an age to fill but if I’m going to do it it needs doing properly.
Also what ‘cleanser’ should I use?

TIA

 

[sarabande]

For all potable water and spraying tasks I use Endosan, which I buy in 20l of Endosan 50. It dilutes to a useable concentration many many times so is, eventually, economical.

As used in a wide variety of industrial and domestic premises.

EndoSan Silver Stabilised Hydrogen Peroxide - EndoSan Stabilised Hydrogen Peroxide

No after taste, no corrosion, can be left over winter, etc etc. Wear PPE for hands and eyes when decanting from the concentrate.



No connection, just a long-term commercial user.

 

[Spirit (of Glenans)]

I’m spending more time in my boat and have ended up with an eye infection. This could be complete coincidence but now that it’s crossed my mind I want to sterilise my tanks. The obvious(?) method would be to run them dry (hot and cold) and then put some/enough cold water and add ‘cleanser’. Then run the pumps to fill the calorifier etc. Does this sound like the best method or do I need to fill the cold water tank as well in case anything is stuck to the sides?
I’ve 1000l stainless tank which takes an age to fill but if I’m going to do it it needs doing properly.
Also what ‘cleanser’ should I use?

TIA

I use crushed Campden Tablets to the recommended dose, but my tank only holds 145 litres.
Your eye infection is probably coincidental, as you would blink your eyes in the shower, and soapy water, as we learned in the pandemic, is an effective bactericide.
Your cold water tank supplies the calorific, so yes, to sterilise the whole system you would need to completely exhaust all fresh water from the system and flush it, before refilling, having first added the necessary quantity of sterilising agent in the required quantity.
A good precaution would be to sterilise a few litres of the marina tap water and taste it, make tea or coffee with it, to see if it is palatable.

 

[vyv_cox]

Just to point out that emptying the tank through the hot water tap does not empty the calorifier, it just bubbles air through it full. Hot water is drawn from the top of the calorifier so you need to drain it from the bottom.

 

[peter gibbs]

For all potable water and spraying tasks I use Endosan, which I buy in 20l of Endosan 50. It dilutes to a useable concentration many many times so is, eventually, economical.

As used in a wide variety of industrial and domestic premises.

EndoSan Silver Stabilised Hydrogen Peroxide - EndoSan Stabilised Hydrogen Peroxide

No after taste, no corrosion, can be left over winter, etc etc. Wear PPE for hands and eyes when decanting from the concentrate.



No connection, just a long-term commercial user.

I agree - eye infection from a water tank is a negligible risk. Keeping tanks clean is good practice for many obvious reasons. Milton is the economic product for this purpose. Private label version is even cheaper and sound for baby bottles so....
Reduce water levels. Spray tank interiors to ensure clean walls. Remove any residue in the tank bottom and remove all water. Refill 20% and dose with Milton. Allow several hours to stand. Draw off water to fill pipes and calorifier. Allow to stand again. Drain down. Tanks ready to recommission. I inserted a water filter (Whale) in the galley cold feed to ensure best quality potable water - worth the small effort.
Great care in sourcing refill water is obvious but not always practiced in the heat of summer. Using long standing water or contaminated hoses is a recipe for trouble - as when delegated to the kids to amuse themselves!! Oh dear.

 

[Refueler]

I bought a box full of Military Tablets - used to purify river / ground water .....

I used to use Milton Tablets but pal of mine pointed me to eBay and the military tablets ... my box of 1000 tablets will outlast me !! and cost was peanuts.

Another way is to use plain laundry bleach highly diluted ...... forget the % ... but sure someone will pipe up about it.

 

[Yngmar]

Chlorine does the job. Use a sterilising dose to flush the tanks, taps, shower head, pipes and calorifier (no need to drain unless there's crud in it). Leave for the appropriate time, clean tank (if you have access) and pump strainer, then flush out with fresh water twice. In the future, use a treatment dose when you refill (no taste if you do it right - takes a bit of practice though). In most countries you can buy it in the household cleaning supplies section, but make sure it's not perfumed or has other additives. Concentration is always on the packaging. Milton sells 5L jugs if you can't find it anywhere else, although it's a bit pricier that way. For treatment and sterilising dosage and times, follow the WHO recommendations. Repeat the sterilising once a year, especially in hot climate.

 

[Momac]

I have used the equivalent of Milton in the past but it takes a lot of flushing to clear the chlorine taint .

So all I have done in recent years is give the tank/pipework a good flush with water only simply by running the taps for an hour or so .


However if you wish to sterilising solution is cheap enough.

 

[Ian_Rob]

Just to point out that emptying the tank through the hot water tap does not empty the calorifier, it just bubbles air through the full tank. Hot water is drawn from the top of the tank so you need to drain it from the bottom.

Interesting. To winterise my boat hitherto, I have just turned on my hot and cold taps and emptied my water tanks with the pump running until there was next to no flow at any tap, just spluttering. I had assumed that I was emptying the Quick calorifier as well. Should I being doing more than this?

 

[vyv_cox]

Interesting. To winterise my boat hitherto, I have just turned on my hot and cold taps and emptied my water tanks with the pump running until there was next to no flow at any tap, just spluttering. I had assumed that I was emptying the Quick calorifier as well. Should I being doing more than this?

Yes, you have been leaving the calorifier full. There is normally a drain tap but if not cold water usually enters at the bottom, so remove the hose, or fitting if there is a nrv there.

(Edit - I have modified my previous post which was a little confusing.)