State Industries GS6, GSX, GPX manual Not Enough HOT Water GAS, Test, Results

BULLETIN 35

NOT ENOUGH HOT WATER - GAS

CAUSES

Complaints regarding an insufficient supply of hot water are typically the result of a water heater that cannot meet the demands of the residence (both people and appliances). The demand for sufficient hot water may also be exceeded if additional people and/or appliances are added to the residence. Another factor that may reduce the hot water output is mineral build-up. Reference Bulletin 13 to determine if mineral build-up may be effecting your hot water output. The following test will help determine if a water heater is supplying the intended amount of hot water.

TEST	Please read all the steps of the test prior to beginning. NOTE: This test is based on
	140° F storage temperature and these amounts are approximate.
STEP 1	Do not use any hot water for two hours to ensure the accuracy of this test. Turn on the
	cold water at full flow using a double handle faucet and time how long it takes to fill a
	one-gallon jug. Calculate the Gallons Per Minute (GPM) flow rate as follows.
	One-gallon Jug filled in:
		5 seconds = 12 gallons per minute
		10 seconds = 6 gallons per minute
		15 seconds = 4 gallons per minute
		20 seconds = 3 gallons per minute
		30 seconds = 2 gallons per minute
STEP 2	Using a thermometer, turn on the hot water and time how long it takes for the water
	temperature to drop 30 degrees.
			Gallons Per Minute (GPM) Flow Rate
			1.5	2	2.5	3	3.5	4	5	6
		30 Gallon Tank	14 min.	10 min.	8 min.	7 min.	6 min.	5 min.	4 min.	3 min.
		40 Gallon Tank	18 min.	14 min.	11 min.	9 min.	8 min.	7 min.	5 min.	4 min.
		50 Gallon Tank	23 min.	17 min.	14 min.	12 min.	10 min.	9 min.	8 min.	6 min.
		65 Gallon Tank	30 min.	22 min.	18 min.	15 min.	13 min.	11 min.	9 min.	8 min.
		75 Gallon Tank	35 min.	26 min.	21 min.	17 min.	15 min.	13 min.	10 min.	8 min.
		100 Gallon Tank	47 min.	35 min.	28 min.	23 min.	20 min.	17 min.	14 min.	11 min.
		119 Gallon Tank	56 min.	42 min.	33 min.	28 min.	24 min.	21 min.	17 min.	14 min.
				Minutes to drop 30° F

Example: 10 seconds to fill the one-gallon jug equals 6 gallons per minute flow rate. If the temperature drops 30 degrees in 6 minutes that equals 36 gallons of hot water. This is normal for a 50 gallon water heater. The amount will be about 70% of the capacity of the heater.

RESULTS

If the test performed above results in a 70% (+ /- 10 %) capacity, then the heater is performing per specifications and a larger water heater should be considered in order to meet the demand.

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