Central Heating (basic question)

maveli

At what stage the hot water tank in the hotpress refill. say I put the boiler for an hour and got a full tank of hot water. Will it wait till the last drop of hot water to run out before it refills. Or does it wait till I put the boiler back on. If it is the later how can I use the immerson heater to heat the water ?

Thanks
Maveli

latecomer

In a normal system with a hot water tank, the feed comes from a cold tank in the loft and its fed by gravity so as the hot water is drawn out, cold water is pulled in so it should always be full.

maveli

latecomer wrote: »

In a normal system with a hot water tank, the feed comes from a cold tank in the loft and its fed by gravity so as the hot water is drawn out, cold water is pulled in so it should always be full.

Doesn't that make the whole thing inefficient ? If it continuously refilling that will make hot water cold ?? I thought it will wait till all the hot water ran out

keith969

The cold feed enters the HW tank at the bottom. As hot water is less dense than cold water, it stays at the top where it is drawn off.

ormus

not really. the hot water is always at the top of the cylinder, and the cold feeds in from the bottom.
one replaces the other automatically. the beauty of the system is the simplicity.
your way, would require all sorts of valves and safety devices. more to go wrong. and expensive.
the old system can run happily (sometimes for decades) without attention.

McKneff

My year ago the back boiler on our open fire didnt fill up again after it was emptied of hot water.
Fire on next day onto an empty boiler, you can imagine the bang and the mess when the boiler blew up..........

1984ReturnsForReal_2

maveli wrote: »

Doesn't that make the whole thing inefficient

Yes.

But the alternative is to buy another boiler which heats on demand...