HOW Your Expressions 550S Shower Works

HOW YOUR EXPRESSIONS 550S SHOWER WORKS

1.Water is heated instantaneously as it flows over the heating elements in the copper cylinder (diagram 2).

2.The heaters are only switched on when sufficient water is flowing.

This is done automatically with a switch which works on water pressure and is indicated by the “High” or “Medium” light illuminating, depending on whether Button “A” or “B” has been pressed.

3.The water is turned on and off by the solenoid valve built into the shower. This is switched on by pressing Button “A”, “B” or “C”.

4.The flow of water is automatically held at the level set by the user even though the supply pressure may vary (see “Effect of Other Water Devices on Incoming Water Supply”).

5.If the water supply falls below a set limit, the pressure switch will operate and switch off the

power to the elements. This is indicated by the “Low Pressure” light illuminating (see “Effect of Other Water Devices on Incoming Water Supply”).

6.As a further safeguard, a thermal cut-out switches the power off if the water temperature climbs above the set limit and the “Overheat” light will illuminate.

This cut-out, which gives an audible click, may also operate due to residual heat when the shower is switched off. It will reset itself if water is run through the shower for 10 to 20 seconds, and the “Overheat” light will go out.

7.The pressure relief device is to safeguard against abnormal pressure conditions.

Effect of Seasonal Incoming Water Temperature Changes

The required water temperature is achieved by adjusting the rate of water flow. Diagram 3 shows the principle involved in relating temperature rise to flow rate. The higher the water rate the lower the temperature and vice versa.

The temperature of the water supplied from the mains can vary considerably throughout the year from 5 to 20°C.

This means that in the winter, flow rate will be less than in the summer to achieve the same outlet temperature.

In summer the “Medium” power setting may give adequate hot water.

In some winter conditions, it may be necessary to select the inner or outer spray pattern only of your shower handset. This will ensure correct operation of the shower with a slightly lower flow rate.

Effect of Other Water Devices on Incoming Water Supply

Your shower is designed to stabilise temperature changes caused by water pressure fluctuations. These can result from toilets being flushed or taps being turned on and off.

When this happens your showering temperature will be held within a controlled band, provided that the minimum pressure required by the shower is maintained.

Your shower requires a minimum operating pressure of 69kPa (0.7 bar, 10 psi).

At pressures above 69kPa (0.7 bar, 10 psi) it will minimise temperature fluctuations as detailed above. If the water pressure falls below 69kPa (0.7 bar, 10 psi) it is likely that the pressure switch will turn off the power to the heating elements, resulting in a cold shower.

This will be indicated by the “Low Pressure” light illuminating.