Gravity Hot Water System Diagram

Gravity hot water recirculating system a gravity hot water system works because the heated water which is lighter rises through the loop.

Gravity hot water system diagram.

A gravity system is easily identified there will be four pipes connected to the boiler. A guide to the different ways of heating domestic hot water so you can identify problems and faults with the hot water tank or central heating system and carry out any maintenance needed. I have to. There is no separate header tank and heating coil inside the hwc as in modern systems.

It consists of a cistern or holding tank at a higher elevation than the point of use. The hot water taps will be fed from the tank in the loft which flows by gravity down to the hot water cylinder and forces hot water out to the hot water taps. In those days you could liken the difference between a gravity how water system and a steam system to that of an open simmering pot of water and a pressure cooker gone berserk. Hot water systems on the other hand were open to the atmosphere and relatively safe because the old timers usually limited them to a high temperature of 180 degrees f.

Hot water takes a long time to replenish. Frequent boiler firing as water thermocycles. Old unmodified gravity systems are usually direct which means the water from the hot taps and hot water cylinder is the same water that is circulating through the radiators. Water may be too hot.

As the water cools at the end of the loop where the last part of the loop is not insulated it is thermo siphoned back into the hot water heater dear tim. This allows gravity to do all the work of moving the water through the system eliminating the need for a water pump whether mechanical or electric. I am not a big fan of cold showers. Some systems also feed cold water to bathroom cold taps and the toilet cistern so the only mains water is going to the cold tap in the kitchen.

A guide to the most common types of domestic heating and hot water systems with diagrams including indirect boiler system unvented system thermal store.