There are a variety of possible reasons that would cause water not to go down when flushed. The most common reasons are (1) an object has been accidently (or spitefully!) flushed in a previous flush and lodged within the toilet or the drain pipe. (2) Build up has formed in the toilet line so that the normal contents plug the line temporarily. Solutions: mechanical snake. If necessary remove toilet. Prevention: (1) None known (2) Treat toilet line with microbial build-up remover product periodically.
Presuming there is water in the tank...the chain from the handle to the flapper is disconnected.
Replace the fill valve.
to use less water when flushing
If the electricity for the water power plant goes out, water cannot be pumped to your toilet for flushing.
If activities like watering the lawn or flushing the toilet were done with grey water instead of fresh water, more fresh water would be conserved.
industrial water has chemicals in it and even after it has been treated it is inadvisable to use it because it contains so many chemicals that cannot be removed from it
Probably not. It sounds more like a faulty water pump, water tank, or well. Most likely the water pump is directly at fault, but faulty tank pressure, bad electrical supply, or a bad well can cause the pump to do that. Especially if the surges are repetitive in nature, your pump is short-cycling. With lots of research, you might be able to narrow down the problem.
Low water pressure or cold water main undersized.
If your water comes from a well and you have your own pump and tank. The tank may be waterlogged.
Each flush of a toilet uses the same amount of water.
No
It will be exaclty the same, the only difference is that flushing the toilet with bottled water is very expense. It really will be a waste of money.
Flushing a toilet
I reckon there is no air vent pipe on the drain line of the toilet you are flushing and the siphon action is sucking out the water in the loft toilet also.
to use less water when flushing
Sink is not vented properly and the water from the p-trap under the sink COULD be sucked out by the hydrostatic pressure from the toilet flushing.
1.6 - 3.5 gpf
That is a matter of debate. Lets say you choose to have untreated water with harmful bacteria including the causes of typhoid and chlolera pumped into your toilet so you will not be wasteful. Then your toddler plays with the water in the toilet and gets sick and dies. I choose to be "wasteful".
It depends on the way it is set up, normally the water is from the same source, but using water in the toilet for any purpose other that flushing is NOT recommended..