Hi

I have a gravity fed hot water system with a galvanised steel cold water tank that feeds the hot water cylinder only i've read some feed cold water taps too but my tank only has 2 pipes out one is the overflow and one goes into the bottom of the cylinder the water tank has corroded quite badly and has started leaking only a pin p***k I suspect but its time to replace it.

my main concern is if the leak gets big enough to drop its entire however many litres of water so have drained the tank by isolating the water to the tank and opening the hot tap until it is almost empty I suspect this means the cylinder is empty too and there is no way of isolating the cylinder from the heating system ( very basic ideal mexico floor standing boiler single mechanical thermostat in hallway and mechanical time switch)

My first question will the coil in the indirect cylinder over heat and get damaged?

second Have I missed a way to isolate the cylinder ? or third will i simply have to switch of the boiler and put a jumper on

its going to be a few days before the tank can be replaced but don't want to cause any damage in the meantime


sorry for the long post and thanks in advance

hi seco thanks for your reply
if the water goes from the cold water tank into the cylinder and from the cylinder to the hot taps how can the cylinder still be full? as you can see I have no understanding of the system

The water pressure from the cold tank in the loft forces water out of the top of your hot water cylinder. Water can't flow uphill so when there is no more pressure, IE when the cold tank is drained, the water stops flowing out but remains in the hot water cylinder

Thanks muggles that makes sense so I assume no water will come out of the hot taps at all?
sorry for the stupid questions

The word 'only' refers to the cylinder.

I expect he does have a F and E tank.

Regardless, I hope the plumber replacing the tank will check.

OP, how much have you been quoted for a new tank? What will be done with the old one?

Tony

Hi

there is a F&E tank in the loft for central heating, cold water tank is purely for cylinder it does have a coil I have had three quotes ranging from £160-£190 I was hoping to weigh in the old tank for scrap

Don't think it worth much.

Some plumbers might leave to one side in loft. Check that your loft hatch big enough to take it out.

Make sure it has bylaw 30 kit.

Use plywood, not chipboard, for platform.

Dan.

Days of old, drill the hole and then put a bolt through with metal washer and rubber washer,same other side and tighten.

Back when i started you had to get your tank made then take it to the local waterworks yard where they would test it,approve it and stamp it.

I was lining wooden boxes with sheet lead and soldering the corners with a lump of iron ( soldering iron ) and grade D solder . Quite often I had too many irons in the fire Then we went onto steel tanks and I used to spit the rivets into the holes and peen them with that same soldering iron ( couldn`t afford a ball pein hammer ) Then we`d melt some zinc in a homemade furnace and do our own galvanising .Then walk 5 miles home across the Forest , checking the rabbit snares and arrive home with a skinned and gutted coney for the pot

Fekk me Nige, you are old. I saw they doing this on Time Team.



Andy

Its about 10 years since I last replaced one in a loft and that was for about £260. I did one in a cupboard for a 93 y.o. last year though.

Since the new rectangular tanks are closer to £150 just to buy I had imagined about £330 was about the price now.

Then if the old galvanised one cannot be removed about £45 extra to cut it up and remove in pieces. At tht least the last old one a few months ago was collected by someone!

Tony

Hi

The tank is not in the loft its on a platform above the cylinder just remove a panel above airing cupboard door and voila it s being replaced with a poly tank no point spending money on a galvanized tank as the system will be replaced entirely within 5 years just preventetive maintenence cheaper than a flood I reckon and it does include the bye law 30 kit I am up north so I guess the price reflects that