Why doesn't hose down surrounded by my geyser stay hot for long? I have a geyser (storage dampen heater) that was installed around 5...

I have a geyser (storage dampen heater) that was installed around 5 years pay for. Earlier, if left ON for 15 minutes, wet used to stay hot for at least 3-4 hours. However lately 5 minutes inwardly switching off, marine turns cold.
What could be the reason? The sea here is hard and does form scales inside vessel. Could this be the cause?
What are the option to repair it?
Why won't a toliet bowl fully flush? I...
Answers:    may b becoz u tooo hot to get d river warm adequate to suite d temperature of ur body
We own topical wood floors and they are...
focus the trouble is with insulation factor
insulating system needs to be repaired.