Cold water storage tank - replacment with two joined tanks?
- Thread starter TheGovernor
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I care and like to chuckle @ BG - was it FOC under a plan you have with BG ?
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The reason the pump requires a min of 50 Gallons will be to avoid the pump emptying the tank. So if each tank us fitted to a different outlet, that requirement won't be satisfied. Unless I misread the post.
When 3 tanks are fitted in series, the volume of water below the connections will be disregarded in calculating the total volume, as it can never be actually effectually used, just turned over
When 3 tanks are fitted in series, the volume of water below the connections will be disregarded in calculating the total volume, as it can never be actually effectually used, just turned over
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I hadn't considered that actually, we have three 20 gallon tanks, so although the total volume of water is right, there's a risk that a tank will empty before it refills if a shower is running. So a tank could empty in 5 minutes, but it is being fed by the other tank(s) which will offset that a bit.
I'm going to get the lids off and run each shower and watch what happens. The problem these days is that they guys who come out don't have brains like engineers, they know how to connect pipes together, but don't really have a grasp on the physics of what they're doing.
A guy came out yesterday and solved all the leaks which is one good thing, you've now got me worried we're going to empty a tank faster than it'll fill and someone is going to get scalded!
By the way, yes, this was all done via my BG Homecare cover, depending on what I find as I experiment if the worst comes to it I'll pay someone to rip it out and fit a coffin tank.
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Gov: The hot and cold must come from the same tank. The cold feed to the shower should be BELOW the hot feed to the cylinder. If above, the cold will empty before the hot and scalding will be a major risk. I would check to make sure they have not got that wrong, or that the cylinder feed and shower cold are not from different tanks.
EDIT: Not trying to contradict Nige, posting at same time
EDIT: Not trying to contradict Nige, posting at same time
If the risk of the tank becoming close to empty is a serious one then a float switch could be fitted in the tank to provide a warning of immiment loss of water. One step further would be to use the float switch to disable the supply to the pump before the pump can run dry ( assuming the warning is ignored )
Thanks guys 
The outlet feed to the hot tank is NOT above the cold feeds (in fairness it wasn't on the old tank either). All the feeds are at the same level.
I may need to draw a picture to describe this better, but the hot feed to the cylinder comes from Tank 1, depending on which bathroom you're in the cold feed will come from the same tank (Tank 1) or one of the other two tanks.
So, actually thinking about it, the greatest risk is Tank 1 because that is feeding both the hot cylinder and one of the bathrooms directly...
If it makes a difference, the showers are Mira Digital ones, which balance the temperature, I don't actually know what happens if the cold feed stops I'll have to check the manual, I'm hoping they'd have some sort of thermal cut off... not that either plumber had a Scooby about them, so they didn't take any other safety features into account.
The outlet feed to the hot tank is NOT above the cold feeds (in fairness it wasn't on the old tank either). All the feeds are at the same level.
I may need to draw a picture to describe this better, but the hot feed to the cylinder comes from Tank 1, depending on which bathroom you're in the cold feed will come from the same tank (Tank 1) or one of the other two tanks.
So, actually thinking about it, the greatest risk is Tank 1 because that is feeding both the hot cylinder and one of the bathrooms directly...
If it makes a difference, the showers are Mira Digital ones, which balance the temperature, I don't actually know what happens if the cold feed stops I'll have to check the manual, I'm hoping they'd have some sort of thermal cut off... not that either plumber had a Scooby about them, so they didn't take any other safety features into account.
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Give up, Bernie. Get back to your agony aunt column. A flow switch is NOT the answer. Do it properly. Hot above cold, same
Thanks guys
The outlet feed to the hot tank is NOT above the cold feeds (in fairness it wasn't on the old tank either). All the feeds are at the same level.
I may need to draw a picture to describe this better, but the hot feed to the cylinder comes from Tank 1, depending on which bathroom you're in the cold feed will come from the same tank (Tank 1) or one of the other two tanks.
So, actually thinking about it, the greatest risk is Tank 1 because that is feeding both the hot cylinder and one of the bathrooms directly...
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Gov: This is wrong. The Hot should be ABOVE, not level. You MUST have a common source. The shower almost certainly will have a thermal cut off, ours claims to do so within 2 seconds (but that is long enough to sting a bit
). However, the timescale is dependant upon other conditions being satisfied.This is all basic apprenticeship stuff, and anyone working for BG should know it. Get them back to sort out properly.
PS. Always give Bernies advice a wide berth. He is typically wrong about most stuff. he actually goes on tho explain why it is a stupid idea
Just had a thought. It can be difficult for a civilian to argue the toss over something that the trades should know, especially if you say "you read it in the 'net). Before contacting them, either find your shower installation manual,or google for it. The manual probably states the conditions that I outlined.
I had not previously notice that it is DynoRod doing this. Suffice to say that I know the local Franchise owner, loaded with wealth, but a good guy, and he said once to me that most of the jobs they did were basically DIY jobs.
Don't let them fob you off. They can not use the excuse that it was wrong before - it is their responsibility to do it properly. Last man in, and all that
Obviously the having hot feed taken from a point above the cold feed is the assured way to avoid the shower running scalding hot. But looking at the wider picture an enpty tank may have other repercussions such as ( but not limited to ) an air lock being created.
he actually goes on tho explain why it is a stupid idea
The float switch in addtion to the correct placement of hot above cold.
Perhaps I should explain things in clear language for those who need a full explanation.
Thanks as ever gents.
I did a bit of experimenting today to see how quickly each tank empties when each shower is running. I actually recorded it as I didn't know what result I'd get
I ran each shower in sequence and let the system refill after each run, and to be fair, got nowhere near emptying any tank after 5 minutes, by my reckoning it would take at least 15 to 20 minutes of continuous running to empty a tank and that could only happen if the mains feed stopped, as that seems to keep up reasonably well.
I did the same with each bath, again after 5 minutes, although much more water was used it would be pretty hard to empty a tank. So from the point of view of that emptying risk I feel a little bit better than I did.
If you're interest, the most boring video on You Tube shows my new system configuration Here:
That said, I think having the hot above the cold is a WRAS requirement? With multiple tanks the guidance is to connect them in series and have the output at the far end from the feed, I don't know if they can argue they've got around it by adding more connection to each tank?
I do wonder how people who know literally nothing about these things (say OAP's) are supposed to be able to check things, it seems you definitely can't have faith that the tradesmen know what they're doing and will fit in the best interest of the customer. It's a whole other subject but I shouldn't be having to check their work or worry they've not done it right, in truth it should be impossible for me as a civvy to question any aspect of a tradesmen's work, but it happens so often to me it must be extremely prevalent.
I did a bit of experimenting today to see how quickly each tank empties when each shower is running. I actually recorded it as I didn't know what result I'd get
I ran each shower in sequence and let the system refill after each run, and to be fair, got nowhere near emptying any tank after 5 minutes, by my reckoning it would take at least 15 to 20 minutes of continuous running to empty a tank and that could only happen if the mains feed stopped, as that seems to keep up reasonably well.
I did the same with each bath, again after 5 minutes, although much more water was used it would be pretty hard to empty a tank. So from the point of view of that emptying risk I feel a little bit better than I did.
If you're interest, the most boring video on You Tube shows my new system configuration
Here: That said, I think having the hot above the cold is a WRAS requirement? With multiple tanks the guidance is to connect them in series and have the output at the far end from the feed, I don't know if they can argue they've got around it by adding more connection to each tank?
I do wonder how people who know literally nothing about these things (say OAP's) are supposed to be able to check things, it seems you definitely can't have faith that the tradesmen know what they're doing and will fit in the best interest of the customer. It's a whole other subject but I shouldn't be having to check their work or worry they've not done it right, in truth it should be impossible for me as a civvy to question any aspect of a tradesmen's work, but it happens so often to me it must be extremely prevalent.
It's not so much 'tradesmen' (be careful... there are many here, giving you assistance) - it's more to do with operatives employed by a large company, who are constantly being badgered by Management to get done and get out and, more often than not, precisely what they should do when there, and how... regardless of it being the correct thing to do!
I speak from experience and left the organisation I was employed by, due to such matters... "you are not being paid to think" was a common rebuke!
I speak from experience and left the organisation I was employed by, due to such matters... "you are not being paid to think" was a common rebuke!
A fair point, maybe I'm just unlucky, but even when I use Independent ones I have hassle, maybe it's my face
If you say so Bern.
It just, though, sounds like a back track. No one on their right mind would do as you suggested.
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