Water Pressure and Flow Inspection – Checking Flow Velocity
During the bathroom inspection, check the water flow by simultaneously turning on the faucets in the sink and tub and flushing the bowl. When the second faucet is turned on, there will likely be a drop in the flow velocity. This is a normal occurrence, but if the flow is noticeably low, record the condition on your worksheet.
A water pressure and flow inspection should be conducted, but do not check the flow for both the hot water and the cold water at the same time. The cold-water flow may be good and the hot-water flow poor. In some cases, when the domestic hot water is generated through the heating system, deposits form in the tankless coil, thus restricting the flow. If the hot-water flow is poor, the tankless coil may need replacement.
Open and close the faucets rapidly. If you hear a hammering and vibrating noise, it means the water flowing in the pipe comes to an abrupt stop. It introduces hydraulic shock and vibrations that can, in extreme cases, damage the pipe or fittings. This condition can be easily corrected by installing an air chamber or antiknock coil to provide a cushion of air to absorb the shock when the water flow drops.
Next, check the drainage in the sink, tub and bowl. Throw some toilet paper into the bowl and flush it. The paper should be carried down the drain. If the water in the bowl starts to rise to the top and then settles without flushing, it means there is a blockage in the drain line. This condition must be inspected further and corrected immediately. This condition may also indicate a problem with the septic system, if the house has one. If the water in the sink or tub does not drain away or does not drain properly, there is a blockage in those drains that should be corrected as well.
Examine the sink and tub faucets. When the tub and sink are filled to the flood rim, an air gap should exist between the top of the water and the bottom of the faucet spout. If there is none, the faucet is susceptible to back siphonage, i.e. dirty water flowing back from the sink or tub into the potable water supply because of a negative pressure in the line. This condition stands in violation of the plumbing code, but it is sometimes found in older homes.