Cold water tank in loft, should this be sealed?

[Deluks]

We have two water tanks in our loft, one is lagged and has a lid and the outgoing pipes are lagged, so I presume this is something to do with hot water taps or central heating.
The other is a much older white plastic tank, containing cold water. It doesn't have a proper lid, just an old sheet of plywood resting on top which doesn't fit properly, there is a gap on one edge. There is some 'debris in the bottom of the tank, as well as cobwebs inside above the waterline, and even a dead 'fossilised' fly on the inside of the plywood sheet. The plywood has turned black at one end, has peeled away and is dipping into the water.
When I turn on the cold taps in my bathroom, the ballcock activates and the tank starts to refill (much to my horror)

Does this mean that the water inside that tank contains the cold water that I brush my teeth and gargle with every day? and if so, how long have I got to live

Is this a potential major health hazard and should I replace the tank or just get a new lid?

 

[Bahco]

Does this mean that the water inside that tank contains the cold water that I brush my teeth and gargle with every day? and if so, how long have I got to live

The tank in question most probably feeds your cold bathroom supply and hot. It won't kill you but it is not very hygienic.

Suggest you have it replaced with a new plastic one with byelaw 30 kit ASAP

 

[felix]

A tank should never be sealed in the sense of being airtight. For a start there is always a hole in the lid where the vent pipe goes in. You have got a vent pipe over your tank haven't you?

A white plastic tank sounds just fine but the lid could be better. When we first moved into this house I found the excuse for a lid quietly rotting away IN the tank - and an old bill from the excuse for a plumber who fitted it!

If your tank is old like mine you might have trouble finding a lid to fit. I made a lid in the form of a thin box with a sheet of formica as its base. I filled this with fibreglass and put a large funnel through it for the vent to discharge into (while also using a preposition to end a sentence with).

You have indeed been brushing your teeth with water that a fly has crapped in. I wouldn't be too bothered about this. That water has chlorine in it to kill germs and you can't have swallowed much anyway. What you SHOULD check is that the cold water in your KITCHEN doesn't come from the tank.

 

[Deluks]

Thanks for the replies. I'm quite certain that the kitchen is fed from the mains, which is just as well cos I'm now brushing my teeth in the kitchen!

There isn't any form of vent pipe, but there's an inch gap all along one edge, which is perfect for letting flies/spiders in etc

I guess a visit to the local wickes is in order, they have a 25 gallon cold water tank in their catalogue for £21.99. would that do the trick? (Obviously I'd get a plumber to fit it but I wanna make sure of the cost of materials beforehand)

thanks again

 

[Bahco]

You should have a vent pipe if you have a hot water cylinder.
Best to let a plumber inspect your system andupgrade what is necessary

 

[felix]

To clarify things a bit, the vent pipe doesn't come OUT of the tank. It comes up from below and loops over so as to discharge INTO the tank. Do you have one of these?

 

[swelec]

(Obviously I'd get a plumber to fit it but I wanna make sure of the cost of materials beforehand)

Delux

This is a DIY forum where advice is freely given by many trusted tradesmen

Changing a cold water tank is one of the simpler DIY plumbing jobs

Why not give it a go yourself