AQUA PLUS
Troubleshooting (continued)
Temperature/pressure relief valve lifting or weeping
1Undersized or missing domestic water side expansion tank?
•Is there a thermal expansion tank installed on the domestic supply piping and is it properly sized?
•A thermal expansion tank is required if the domestic supply piping includes a backflow preventer or pressure reducing valve.
•Ensure the potable water expansion tank is properly sized according to the water heater volume and supply pressure.
•During long periods when there are no draws from the tank (i.e. overnight), the T&P relief valve may lift or weep due to thermal expansion, but may function properly during normal periods of tank draws.
2Faulty domestic water side expansion tank?
•Is the expansion tank defective, water logged or improperly charged?
•Check for failed gaskets or bladders, or a faulty Schraeder valve.
•Use a tire gauge to check the charged pressure of the tank.
3Faulty T & P relief valve?
•Is the temperature/pressure relief valve functioning properly? Dirt and water deposits can accumulate under the valve seat.
4High domestic water supply pressure?
•Check the domestic supply pressure entering the water heater.
•If the pressure is over 70 psi it is recommended to install a pressure reducing valve. A thermal expansion tank is required if a PRV is installed.
•This will prevent any pressure spikes or increases in pressure due to thermal expansion which may cause the T&P valve to lift or weep.
5Possible water hammering or pressure spikes?
•Check the domestic system for possible sources of water hammering or pressure spikes.
•Some appliances such as clothes washers and dishwashers utilize fast acting valves which may cause water hammering or pressure spikes through the domestic water system.
•Install water hammer arrestors as required per the manufacturer’s instructions, or install flexible connectors to isolate the tank from the domestic system
6Check boiler operating temperature.
•If the boiler operating temperature is too high, stacking can occur in the water heater raising the domestic water tempera- ture close to the boiler operating temperature. — Reduce the boiler operating temperature to 180°F. Also follow page 32 suggestions if the problem persists.
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