Colour changed to black at the request of Grundfos.
Installations which have a long pipe run to the final hot water tap or shower may suffer from excessive draw-off (and therefore wastage) of water that has cooled in the pipe, before the required hot water is available. A secondary hot water circuit with circulating pump will overcome the problem, ensuring that no water is wasted, because hot water is immediately available even from the tap furthest from the storage point.
A standard pump would fail prematurely in this application; the pump body is bronze so that it does not react with the regularly replenished (and therefore oxygenated) water. The bronze pump should be installed in a return loop added to the hot water supply plumbing after the furthest tap in the circuit. The return tapping should be into the upper third of the hot water storage tank (in order to avoid de-stratifying the tank contents).
• Run the secondary re-circulation pump from the timer / programmer hot water output (least efficient)
• Run the secondary re-circulation pump on a cycle timer for short periods at intervals during programmed hot water output times.
• Run the secondary re-circulation pump from the timer / programmer hot water output, in series with a pipe thermostat fitted to the re-circulation loop, after the last tap.
The pipe thermostat should be adjusted to 5°C below the main hot water tank thermostat. (Highest efficiency) All pipes should be well insulated in order to minimise heat loss.
Bronze Body Domestic Hot Water Recirc Pump
Model: Bronze pump
Energy Efficiency Index: <0.4
Power: 230V 50Hz
Structure: Single-stage Three-speed Centrifugal Pump
Type: Circulator Pump
Application: Domestic Hot Water secondary re-circulation.
Standards: CCC, CE, GS, RoHS, ISO9001: 2000
1) Max Head: 6m
2) Power/Speed: 100W/III, 70W/II, 55W/I
4) Pump body material: Bronze
5) Pump body length: 130mm
6) Joint type: Screw G1
7) Joint dimensions: 1 1/2″
8) Max system pressure: 1.0Mpa
9) Max. temp of fluid being pumped: TF 110