Inadequate Hot Water
Possible Causes
- Unit is undersized for water heating demands
- Broken or damaged dip tube allowing cold and hot water to mix in tank
- Faulty plumbing installation has crossed cold and hot water connections
- Gas supply or control problems
- Faulty electric lower heating element or high or low heating element thermostat
Possible Repairs
- Make sure water heater is not being overtaxed by hot water supply demands. The water heater should have 75% of its capacity as hot water (e.g., a 40 gallon WH should be used for a demand of 30 gallons). To determine required capacity see Calculating Fixture Flow Rates.
- Undo cold water inlet and pipe nipple and remove dip tube. Check condition and replace if required.
- Check for crossed connection by turning off water supply to water heater. Open hot water tap at a faucet. If there is water flow, then the a cross connection exists somewhere. Check for a hot water line connected to a cold water connection on the water heater or appliances such as washer, dishwasher, faucet or shower valves.
- Check for proper flame from burner. A natural gas flame should be a bright blue with the tip of the flame having just a tinge of yellow. A propane flame should have a bluish green flame with a tinge of yellow at the tip.
- Check for power and electrical continuity at the lower heating element. Replace if needed but clear tank of any sediment first.
- If element tests OK, check for power at upper electrical upper thermostat. If OK check lower thermostat. Replace if necessary.
