Isolate a vented hot water cylinder

[Saahil]

Hello guys,

This is my first post so apologies in advance for any of my ignorance.

I have got 2 vented 105 litres in-direct hot water cylinders installed, out of which I would like to isolate 1 to save cost in heating both. All I wanted to know if the steps below are right to isolate it.

1. isolate cold water feeding the 2nd hot water cylinder at gate valve.
2. isolate the hot water rising from the 2nd hot water cylinder with a gate valve.
3. Isolate the boiler flow feeding into the 2nd hot water cylinder with a isolating valve, I cannot isolate the return back from the 2nd cylinder due to its location, is it a problem? What valve is best to isolate the boiler flow into the cylinder?

Please advise.

Thanks in advance.


regards.

 

[Ch4 plumbing]

Sounds okay to me although instead of gate valves use lever valves and label and remove handles. Also I would advise draining the redundant cylinder of water.

Out of interest how many people and appliances are relying on the cylinders? Doesn't seem like a lot of stored water.

 

[Simon F]

is this to use 1 mostly and the other occasionally?

if 1 cylinder is never to be used then it needs to be completely disconnected and any pipe dead legs removed.

if it is to have occasional use of the second, the valves would work,
but best to have a time switch, thermostat and 2 port valve to each cylinder.
and alternate between use of both to avoid water issues.

Don't isolate feed and supply, it is then not vented!

Having said that we can't see how it is piped up at the moment!

 

[Saahil]

Thanks for replying.

We are family of 4, 2 adults and 2 kids plus usual appliances (washing machine, 2 bathrooms (1 occasionally used) and 1 sink). The only reason for me to isolate the 2nd tank is, both tanks gets heated up at the same time to full heat and they loose all the heat within 45 min to an hour (after the boiler is off), even if i do not used hot water at all or use 4-5 litres only. I do not see the point of heating up more than 200 litres just to use 5-10 litres at a time.

Is the above duration of loosing heat from water is normal? the cylinders were newly installed in January 2015 after the previous cylinders had lime scale built-up.

regards,

 

[Best]

Why are you loosing all the heat from the cylinders in 45 minutes?
I assume the cylinders are foam lagged types, or at the very least have jackets?
It is possible to loose all the heat if you have heating pipes connected to the cylinders coils & going up overhead & down to a back boiler - like in a bungalow. The hot pipe work simply reverses the heat by gravity & cools the cylinder by taking the heat to the back boiler.
Or you could have dripping hot taps or hot pipe leaking somewhere!
On the subject of saving money when only needing small amount of hot water ( or as much as you require) try looking up Willis immersion heaters.