Hot water temp. fluctuating

Old 11-27-05, 08:17 PM
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Hot water temp. fluctuating

My hot water heater is a 50 gal. natural gas heater, not sure how old it is, the house was built in 1982, but not sure if the heater has been replaced. The problem I have is the hot water fluctuates a lot. If its ben a while since the hot water has been used(about 12 hours or more), the water isn't very hot and gets cool really quick. Once the heater has kicked on and heats the water to the level set on the dial, it's hot and lasts long enough to take a long hot shower. Could this be a faulty thermostat allowing the water temp. to drop too far before the heater comes on? PLEASE HELP!!!!!
Old 11-28-05, 05:04 AM
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Hello thomasrc and Welcome to our Do It Yourself Web Site and the Water Heaters topic.

I seriously doubt the existing tank is the original one. Domestic hot water heaters do not normally last the number of years that house was built. More likely to be the second or third hot water heater. Age can be determined by reading the manufacturers label. Year coded into the BTU rate plate.

Most commonly, for the problem description stated, the thermostat is defective. Unable to maintain set temp until sufficient cold water reaches the tank bottom where the T-Stat is located.

Problem is, replacing the T-Stat, which would solve the problem may be counter productive and not cost effective on an older tank. Tank replacement of equal capacity or one size larger based upon existing space and hot water demands, etc. would be the best possible solution.

Be sure the appliance is turned off before attempting any repairs. Always check for gas leaks whenever a repair includes any connection of a gas part, gas line or tubing or gas supply.

Read the prior asked questions in this forum on this topic of water heaters and the replies offered. In them you'll find additional helpful information and advice.

If you need further assistance, use the reply button to add any additional information or questions, etc. Using this method also moves the topic back up to the top of the list automatically. Check back on your question several more times. Other members and the plumbing professionals posting replies in this forum topic may offer you additional advice, ideas and or repair methods.

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Old 11-28-05, 09:41 AM
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This site should help you find the age of the heater:

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