Hot water system configuration, descaling and heating methods therefore

A method for reducing delay of hot water delivery at a desired output temperature in a hot water system comprising a main flow line having an input point and a heated output point, wherein a pump, a buffer tank, a heat exchanger, a first temperature sensor and a second temperature sensor are fluidly connected in line with and disposed within said flow line and said pump is configured to move water in a direction of from said input point to said heated output point and burner operably connected to said heat exchanger, an internal recirculation flow line connected in parallel configuration to said main flow line at said input point and said heated output point, said internal recirculation flow line comprises a first adjustable valve and a first check valve for directing flow from said heated output point to said input point, an external recirculation flow line connected in parallel configuration to said main flow line at said input point and said heated output point, said external recirculation flow line comprises a second check valve to prevent flow from said input point to said heated output point through said external recirculation flow line and said first temperature sensor is disposed upstream of said buffer tank and said second temperature sensor is disposed downstream of said pump and downstream of said buffer tank, wherein said method comprises steps of:

• (a) opening said first adjustable valve, turning on said pump to generate a flow in said internal recirculation flow line and said external recirculation flow line and turning on said burner;
• and
• (b) closing said first adjustable valve to stop said flow through said internal recirculation flow line and causing a flow through said external recirculation flow line only.

A method for detecting trickle flow demand in a hot water system for delivering hot water at a desired output temperature, wherein said hot water system comprises a main flow line having an input point and a heated output point, wherein a pump, a buffer tank, a heat exchanger, a first temperature sensor and a second temperature sensor are fluidly connected in line with and disposed within said main flow line and said pump is configured to move water in a direction of from said input point to said heated output point and a burner operably connected to said heat exchanger, an internal recirculation flow line connected in parallel configuration to said main flow line at said input point and said heated output point, said internal recirculation flow line comprises a first adjustable valve and a first check valve for directing flow from said heated output point to said input point, an external recirculation flow line connected in parallel configuration to said main flow line at said input point and said heated output point, said external recirculation flow line comprises a second check valve to prevent flow from said input point to said heated output point through said external recirculation flow line and said first temperature sensor is disposed upstream of said buffer tank and said second temperature sensor is disposed downstream of said buffer tank, wherein said method comprises the step of:

• comparing the output of said second temperature sensor to the output of said first temperature sensor, whereby if the output of said second temperature sensor is higher than the output of said first temperature sensor by a predetermined differential, a trickle flow is indicated.