Cold water tank

[75pete]

Hi All,

I need to renew the cold water tank and have seen that Screwfix does them.

I need a 50gal size and would like any pros / cons before i buy.

Is there any other make worth looking at etc.?

Thanks for any info...Pete

 

[Richard C]

Not many pro’s & cons with a water tank are there! I fitted a Screwfix 50 gallon (it’s not actually made by Screwfix!) 4 months ago to replace 2 very old 25 gall fibre glass tanks. It’s a good price, very sturdy & comes compete with a bylaw 30 fitting kit. Only criticism I would have is that the ball valve supplied is only 15mm so I had to buy a new 22mm unit but that was only another £8; no problems at all, just make sure the base is properly supported.

 

[crockett]

And that the support base is bigger than the tank as well

 

[Whitespirit66]

And make sure that there isn't any loft insulation underneath the new tank. Rising heat will help prevent the tank from freezing.

 

[crockett]

WS66, dunno where you live, but I have never seen a frozen loft tank, even if it hasn't been insulated

The insulation that comes in the Bylaw 30 kit will be enough to protect from freezing / getting too warm in the summer........... unless you live in Alaska

 

[Softus]

And make sure that there isn't any loft insulation underneath the new tank. Rising heat will help prevent the tank from freezing.

Very bad advice.

Keeping the water 'warm' is as inadvisable as it is impossible. If the temperature drops low enough for long enough then no insulation in the world will stop the water freezing.

The purpose of insulating the cold storage cistern is to keep the temperature down in order to discourage bacterial growth.

 

[petetheleak]

You dont want to keep the water warm in storage tank legionella springs to mind for one .

 

[Whitespirit66]

I'm afraid that the last 3 posts are wrong.

If roof tanks don't freeze, why do they need a byelaw 30 kit?


Before people insulated their lofts, does this mean that their roof tanks (often uncovered) were full of Salmonella?

My neighbour is a lecturer in plumbing at the local college. When I asked him about omitting the insulation, he says that this is approved practice, and the City and Guilds course instructs students to fit tanks this way.

He showed me the official C&G text book. Page 200 of 'Plumbing, NVQ and Technical Certificate - Level 2' by M Phoenix and J Thompson. It states 'NO INSULATION BELOW CISTERN TO ALLOW HEATING'.

Water regulations also require that cold water systems should not exceed 25 degrees C. (1) any tiny amount of heat rising to the base of the tank without insulation will never exceed 25 degrees C (2) The optimum temperature for Legionella growth is 36 degrees C.

The intention of omitting the insulation is not to HEAT the water to any great degree, but to raise the temp. slightly to prevent freezing.

If anyone can argue against City & Guilds and the water regulations, go ahead.

 

[Whitespirit66]

And make sure that there isn't any loft insulation underneath the new tank. Rising heat will help prevent the tank from freezing.

Very bad advice.

Keeping the water 'warm' is as inadvisable as it is impossible. If the temperature drops low enough for long enough then no insulation in the world will stop the water freezing.

The purpose of insulating the cold storage cistern is to keep the temperature down in order to discourage bacterial growth.

Before crticizing my advice I think you need to read my post PROPERLY.

I didn't say anything about keeping the water 'warm'. Its all about keeping the water from freezing.

Do you understand that the intention is for the water to be neither WARM nor FREEZING, but somewhere between these two states.

 

[Softus]

I'm afraid that the last 3 posts are wrong.

I don't know why you're afraid, but I do know that you're wrong.

If roof tanks don't freeze, why do they need a byelaw 30 kit?

You imply one question and ask a second.

Firstly, when did you last see a "roof tank" (sic.) freeze?

Secondly, the clue about the "Byelaw 30" kit is in the name. They're fitted in order to make the installation comply with The Water Regulations.

Before people insulated their lofts, does this mean that their roof tanks (often uncovered) were full of Salmonella?

Where did you get the idea that bacteria are prevalent in the water supply? Or do you keep chickens in your loft?

My neighbour is a lecturer in plumbing at the local college. When I asked him about omitting the insulation, he says that this is approved practice, and the City and Guilds course instructs students to fit tanks this way.

Having the title of "lecturer" doesn't make him automatically correct.

He showed me the official C&G text book. Page 200 of 'Plumbing, NVQ and Technical Certificate - Level 2' by M Phoenix and J Thompson. It states 'NO INSULATION BELOW CISTERN TO ALLOW HEATING'.

I can understand your temptation to let someone else do the thinking for you, but could you remind the rest of us why you want to heat the cold storage cistern?

(1) any tiny amount of heat rising to the base of the tank without insulation will never exceed 25 degrees C

Please qualify "tiny", and state why the heat loss will exceed that amount, and indicate how you've calculated the heat transfer rate.

The intention of omitting the insulation is not to HEAT the water to any great degree, but to raise the temp. slightly to prevent freezing.

Guesswork, in other words.

Before crticizing my advice I think you need to read my post PROPERLY.

That's a bit rich, considering how little care you've taken to read mine.

I didn't say anything about keeping the water 'warm'. Its all about keeping the water from freezing.

What is the temperature of the average loft, in winter, when the house is heated and occupied?

Do you understand that the intention is for the water to be neither WARM nor FREEZING, but somewhere between these two states.

Do you understand that asking fatuous questions makes it look as though it's you who doesn't understand?

 

[Whitespirit66]

Sorry, mate. This will probably spoil your evening, but I'm not going to turn this into one of your usual 30 post, aimless, juvenile arguments.

This is my last post on the matter. I will state my case, and let the OP and everyone else make their minds up:

My original post suggested omitting the insulation to raise the temp. under the tank by a couple of degrees. The intention is to HELP prevent the tank freezing in the event of a severe winter. This would probably make sense to most people.

You called this 'very bad advice', then proceeded to imply that I suggested keeping the water in the tank 'warm' which I never did.

I then consulted someone with 25 years plumbing experience, who now lectures on plumbing at college. He is accredited to teach to City & Guilds standards, and assess students during their training. The official text book for City & Guilds plumbing courses specifically says that insulation should not be present below roof tanks.

So it comes down to - a bloke with the nickname of Softus who posts his 'opinions' on here in between doing a bit of plumbing VERSUS a very well established and respected national training and examining institution and their approved text books.

So, as you obviously know better (or perhaps your hobby is arguing the toss for the sake of it), can I suggest that you contact City & Guilds to tell them that they are wrong, and get them to change their books.

 

[Softus]

My original post suggested omitting the insulation to raise the temp. under the tank by a couple of degrees. The intention is to HELP prevent the tank freezing in the event of a severe winter. This would probably make sense to most people.

It makes sense; it's just wrong. That's the bit you keep not understanding.

You called this 'very bad advice', then proceeded to imply that I suggested keeping the water in the tank 'warm' which I never did.

I didn't imply it, but you did infer it.

I then consulted someone...

We only have your word about what you told him and what he said in response. It's hearsay. The very fact that you had to ask someone else shows that you weren't sure about it.

And since you won't be posting again, I can now point out that you avoided the very pertinent question I asked you, which was: when did you last see a "roof tank" (sic.) freeze?

 

[FRANKIEJUNIOR]

if you dont leave your trapdoor open then no heat will get into the loft whether you insulate bottom of tank or not because of the insulation in or which should be up there. dont argue information,pool it.

 

[cashjob]

I must admit that removing the insulation from underneath a cws tank is a bit 'belt and braces', but it was what I was taught when I was only a plumber's tool bag carrier. I must admit that I still do it now.

It does make sense, especially when I started in the trade back when we had proper winters. I haven't seen a frozen tank, but it did use to happen.

Another safeguard to prevent freezing on modern tanks is where the end of the overflow turns down into the water inside the tank. This is to stop cold winds blowing up the pipe and across the surface of the water and freezing it. More belt and braces.

Softus says that he's never seen a frozen tank. Well I have never seen anyone electrocuted, but I make sure I earth bond everything. More belt and braces.

 

[Softus]

I must admit that removing the insulation from underneath a cws tank is a bit 'belt and braces', but it was what I was taught when I was only a plumber's tool bag carrier. I must admit that I still do it now.

I've been taught plenty of things, but the most important one of all was the need to think for myself.

It does make sense, especially when I started in the trade back when we had proper winters. I haven't seen a frozen tank, but it did use to happen.

And on the ones where it happened, had the insulation underneath the cistern been removed? And when it happened, what was the standard depth of insulation:-
6"?
4"?
2"?
Nothing at all?

Another safeguard to prevent freezing on modern tanks is where the end of the overflow turns down into the water inside the tank. This is to stop cold winds blowing up the pipe and across the surface of the water and freezing it. More belt and braces.

Quite so. An intelligent comment. This is one of the reasons why a "Byelaw 30" kit is important.

Softus says that he's never seen a frozen tank.

Please show me where I've said, or implied, what I've seen, or not seen.