Weil-McLain PLUS-E017-A/1206 manual Components

Manual • Installation • Start-Up • Usage • Maintenance • Parts

Figure 9

Recirculation components

Figure 10 Recirculation connection at water heater

Components

1Circulator — Little flow is required to maintain a temperature in the piping. Size of circulator depends on minimum flow requirements of the tempering valve.Minimum flow rates of the tempering valve must be maintained.

2Aquastat — Used to control the on-off position of the circulator.Aquastat is set 5° to 10° lower than mixed water outlet of the mixing valve (#7). The circulator cannot run continuously as bypass through the mixing valve will eventually allow the temperature on the piping to climb to the water heater temperature during draw periods.

3– 6  Check valves — Assure the flow of water in one direction. Each check valve func- tions as follows: #3 and #4 prevent bypass in the event of pressure drop, #5 prevents thermal siphoning of hot water to the cold water supply,#6 prevents flow of cold water to the tempered water supply.A draw of tempered water will not result in flow of cold water into the return loop.

Operation

•During period of normal use (fixtures on) — Circulator is off.There is no flow through #6, there is flow through #5 equal to the flow at the fixtures, there is flow through #3 and/or #4 equal to flow at fixture.

•When all fixtures are off — Circulator is off. There is no flow through #3, #4, #5 or #6. Water temperature in piping is cooling.

•When temperature at aquastat #2 falls 10° below temperature to be maintained

— Circulator is on. There is flow through #6 equal to the minimum required by the mixing valve,flow through #3 and #4 equals the flow of the circulator.There is no flow through #5.

•Aquastat reaches temperature — Circulator is off. There is no flow through #3, #4, #5 or #6.

Problems

•Missing check valves #3 or #4 — Extreme pressure drop can cause reverse flow of water; hot to cold supply or cold to hot supply.

•Missing check valve #5 — Hot water can migrate from the water heater back through the cold water supply.

•Missing check valve #6 — Cold water can be forced back through the tempered water supply when a fixture is opened.

•No aquastat #2 — Pump runs continuously. Small amount of water will pass through mixing valve. Eventually all hot water is flowing through valve. Recirculated water through cold port, hot water through hot port.

•Circulator too small — Mixing valve performance erratic.

Part Number PLUS-E017-A/1206 23