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Using hot water from a vented system for the first time in 2 years


Oxbow16

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Hi all

 

For various reasons, we haven't used the hot water system in our house for a couple of years.  It's a vented system with a tank in the loft.

 

I want to try it out now but wonder whether there could be any potential problems from Legionella or anything else potentially nasty? 

 

I don't know whether the fact that the water has never been heated over the time means it is not a breeding ground for anything dodgy?  

 

And if there is a potential for nastiness, will heating the water in the cylinder make it all safe again?  

 

Or is the best option to run off enough water so that both the tank in the loft and the cylinder have fresh water in them (I'd rather avoid that but if it needs to happen then so be it).  

 

Many thanks

 

 

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Turn the cylinder stat up to 75°C if you’re worried and then run at least a couple of buckets of water out of the system. If you’re really worried just drop a couple of Milton tablets into the top tank, leave 10 mins and stir it then drain off the couple of buckets. 

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Could you not just pop some weak bleach into the header tank, run the hot taps for a few minutes, leave for a few hours. Flush out the system for half an hour, then heat up the water.

The presences of legionella bacteria in the water is not, in itself, a problem. It is when that bacteria is dispersed via water vapourisation, as in air conditioning units (where the problem comes from, not your daily shower) that there is a problem.

 

Edited by SteamyTea
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2 hours ago, Oxbow16 said:

Aha - that makes sense.  Thanks for explaining.  

 

As for the tank, it has a lid of sorts....  A sheet of chipboard to be precise!  

 

Cheers

Better than no lid,  and the pigeons and other vermin drowning in there and you bathing in that soup. Water condition shouldn't be that bad, therefore, so the above advice is ample. Use the electric immersion, if you have one, to sterilise the tank for 24 hrs.

2 hours ago, PeterW said:

Turn the cylinder stat up to 75°C

Only effective if the heat source stat is turned up / capable of delivering that temp ;) 

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Thanks @StormyTea - from StormyCoffee...

 

And thanks @Nickfromwales - from Maxalsofromwales!

 

15 minutes ago, Nickfromwales said:

Only effective if the heat source stat is turned up / capable of delivering that temp ;) 

 

Would the immersion get it to that kind of heat?  Or is that not a simple question to answer!?

Edited by Oxbow16
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Just now, Oxbow16 said:

Thanks StormyTea, from StormyCoffee...

 

And thanks Nickfromwales, from Maxalsofromwales!

 

 

Would the immersion get it to that kind of heat?  Or is that not a simple question to answer!?

They're typically set to higher temps than the boiler stat, because the boiler stat dictates the surface temp of the radiators so are usually set to a max of 60-65oC. Immersions are usually set to 70-75oC out of the box. Simple answer is switch it no and leave it for 3-4 hours, then carefully put your hand on the top pipe of the cylinder to see if it's uncomfortably hot.

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6 minutes ago, Nickfromwales said:

They're typically set to higher temps than the boiler stat, because the boiler stat dictates the surface temp of the radiators so are usually set to a max of 60-65oC. Immersions are usually set to 70-75oC out of the box. Simple answer is switch it no and leave it for 3-4 hours, then carefully put your hand on the top pipe of the cylinder to see if it's uncomfortably hot.

 

Great, thanks for that @Nickfromwales

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3 minutes ago, Nickfromwales said:

@Oxbow16

You can 'mention' a member by typing the @ symbol and then type the first couple of letters of their username. Select from the drop list and bingo ;) 

 

Ah yes, I usually do but an oversight on that occasion.  I've edited it but funnily enough it doesn't seem to work in edit mode.

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20 minutes ago, Oxbow16 said:

I've edited it but funnily enough it doesn't seem to work in edit mode

That is to stop us all from correcting and clarifying what we have typed more than 30 minutes earlier.

So @Nickfromwales, typing this

30 minutes ago, Nickfromwales said:

Simple answer is switch it no and leave it for 3-4 hours

instead of 

Simple answer is switch it on and leave it for 3-4 hours

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Ah, yes - some forums do indeed put those time limits on I've noticed.  With others you can edit years later.  But in the case of the above, I WAS able to edit (if you look you'll see that the @'s have been added through an edit),  it just didn't do the drop down choose a forum member to link to thing when I added the @'s.  

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Took a look at the inside of the tank just now, and whilst there I thought I'd take some photos so those with a more experienced eye could say how it looks in the scheme of things.  I appreciate not all nasties are visible to the eye though!  

 

We've got vermiculite insulation so I think that's what the white floating bits are.  

 

The underside of the "lid" has a coating of white mouldy stuff, so I took a snap of that too.  

 

Thanks to you all for taking the time to help with your replies.  

 

 

IMG_20210822_111122068.thumb.jpg.69948e49442973e23dbd140827ae9e7b.jpg

 

IMG_20210822_111142904.thumb.jpg.3029af5c6d9411d4a19ab4c56b3ba839.jpg

 

IMG_20210822_111152680.thumb.jpg.be36ca0448666685ce1913b119658222.jpg

 

IMG_20210822_111242412.thumb.jpg.28fe1ac7670c89f78f86b6ef9cffbe97.jpg

 

IMG_20210822_111306722.thumb.jpg.95a10570111ef63dc67870ea59e5af0d.jpg

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8 minutes ago, ProDave said:

Before you put it back, take the lid outside and give it a thorough clean with a pressure washer or similar.

Just make a new lid from plastic sheet stuck to some PU insulation.

As Dave says, seen a lot worse, mine for a start.

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Well, good to hear that it at least looks clean.  Taste test next...  I've just baled some out and made my partner a glass of squash using it.  I'll she if she notices anything untoward ;)

 

On a different note, but seeing as we're talking about the tank now, when we get the plumbing work done and the system is drained, I need to have the tank disconnected so that I can change the boards underneath.  I'm now wondering what my best option is.  Would any plumbers mind giving a rough idea of prices/price differences on the following, to help me decide.... 

 

OPTION1 - plumber disconnect pipework to tank, and F+E tank.  I will then do the board replacement work.  Plumber reconnect all pipework with the tanks in the same places.

 

OPTION2 - plumber disconnect pipework to tank, and F+E tank.  I will then do the board replacement work but build a higher platform for the tank for better gravity pressure.  Plumber to extend current pipework for new cold water tank position (F+E wold remain in the same place) and reconnect.

 

OPTION3 - as per Option 2, but fit a new tank instead of the re-using the old one (with proper lid, and an insulating jacket, plus the ball valve isn't looking great).  

 

Thank you so much

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Hi all

 

I think I'm going to stick with OPTION1 and go for the least intervention and cheapest approach seeing as it's always possible we'll have to get a new heating system at some point in the future anyhow.

 

- Lid. I think I'll see if I can get a new decent fitting lid, although not sure how likely that is. Do lids tend to be "unipart"? If not I'll make one as suggested, but where might I find suitable plastic sheet?    

 

- Insulation. I'll get a jacket too. A quick look shows standard types tend to be for a 50 gallon tank, whereas mine is 60. But I'm sure I can hunt something down if they exist.

 

- Cleaning. Think I'll drop some Milton in to be on the safe side. I was thinking also that while the tank is empty I'll give it a scrub and clean, perhaps with a spray or two of anti-this-and-that spray.

 

- Overflow. Someone on another forum pointed out that the overflow should be below the ball valve. Do you think it needs changing? If so, will that involve a whole new overflow, new hole in wall, etc?

 

- Vent pipe. They also pointed out that the vent pipe needs shortening. Will that be as simple as cutting a little off?

 

Thanks everyone and have a great week.

 

IMG_20210822_110909668.thumb.jpg.307ad4cd2ee2145278330e82a500db1d.jpg

 

 

IMG_4008.thumb.JPG.0bd2b2b4e95d341fb13c7ebb33b0eb76.JPG

 

 

Edited by Oxbow16
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20 minutes ago, Nickfromwales said:

Scrap the lot and fit an UVC ( invented cylinder ) to future proof you and de-bug ( lol ) the system for once and for all? 

 

Has that been invented yet?  

 

Seriously though, we have discussed and considered this.  But if/when our boiler dies on us we'd prefer to switch to combi, which is why we don't want to invest more than necessary in the current system.  Thanks for the thought though.  

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