Plumbing in the Home/Hot water heater knocks


Two years ago I replaced a hot water heater that was about twenty-five years old and hadn't been drained in atleast the last ten of those years.  My only symptom was that the hot water started to come out really cloudy.  So anyway, I got my new hot water heater and everything was great.  Then the wonderful city of Stockbridge decided it was tired of constantly fixing its blue-poly issues in our neighborhood ( there was a road patch in front of almost every house) and just swept the whole neighborhood in about a month.  Not sure what they did but we had horrible air in our pipes for weeks and weeks.   I mean I thought the house was coming apart the pipes were so loud.  Anyway, the pipes don't knock anymore, but now the water heater knocks real bad when its filling up.  I know that I haven't drained it yet, but due to these other  considerations, I'm not sure that's really the problem.  What do you think? Thanks,

Jen, I really don't have enough information to answer for sure but I will tell you that in the 40 or so years in the business, I have had customers who drain their heaters religiously and others,myself included, who never touch their heaters and I have seen no difference in the lifespan of the heater or the performance. What will help the heater last longer and work better is changing the anode rod that is inside the heater. It is about 3 feet long ans it screws into the top of the heater. It looks like a flat nut about an inch or so across and is located on the top close to where the water lines tie in. This rod is designed to gradually disintegrate as it gets used up.It is necessary with well systems and public water supplies high in mineral and other impurities. As for the knocking,
Check with your neighbors and see if they are experiencing the same issue. Also call the local plumbing inspector for your city and get him over to your house to see what he thinks. It sounds like there are underlying issues here.

Plumbing in the Home

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Jay Nicholas


Plumbing & Heating (warm air, hot water & steam heat)


40 years in the business, 35 years as a lic. master plumber in NY State. Retired

Graduated Magna cum laude at the School of Hard Knocks

Past/Present Clients
Commercial, residential and light industrial. You name it ...I have probably worked on it

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