Ask Me Help Desk - Water heater knocking sound

My 5 year old water heater would make a loud crackling sound like firecrackers after we have a hot shower. I read that we should lower the temperature (not too hot). I've done that and I've drained the water heater. I have 2 questions:

1. How much water do I drain, is it until the water turns clear or do I have to drain it all the way since I'm sure the minerals are at the bottom of the water heater?

2. I read that sometimes changing the water heater temperature and pressure valve (located on the top or side) would do the trick. Can I do this on my own w/o scalding myself? Its on top so I think its OK but do I need to fully drain all the water out before doing this?

Thank you in advance for any tips!

Quote:

Originally Posted by gleeclub

My 5 year old water heater would make a loud crackling sound like firecrackers after we have a hot shower. I read that we should lower the temperature (not too hot). I've done that and I've drained the water heater. I have 2 questions:

1. How much water do I drain, is it until the water turns clear or do I have to drain it all the way since I"m sure the minerals are at the bottom of the water heater?

2. I read that sometimes changing the water heater temperature and pressure valve (located on the top or side) would do the trick. Can I do this on my own w/o scalding myself? Its on top so I think its ok but do I need to fully drain all the water out before doing this?

Thank you in advance for any tips!

My 8 year old water heater has recently been making a crackling /knocking sound.l I have replaced the rod that collects all the sentiments of the heater. It was replaced 2 years ago. Is this noise of any concern? Please advise.

I am looking for a reason why my 8 year old water heater is crackling/knocking when it starts up in the a.m. or later in the day when it has not been in use? I have replacedd the rod thatcollects sentiments. That was done 2 years ago.

Is this sound of any concer? Please advise.]

Hi all... Hey start by draining your water heaters... sounds like mineral deposits are causing issues for both of you.

Here, you hook up hose to heater and with WATER STILL ON open the hose full and flush the tank for a good 2-3 minutes. See the sediment builds up and collects at heater bottom.. so when heater heats water it has to heat through the sediment... kinda bubbles/boils at interface and can cause these sounds you guys are hearing/feeling almost... huh?

Try this.. see if improves.. if does, just want to flush 2 times a year.. same way. If does not... get back to us.

Also note that you may need a HOSE CAP (sold at home supply stores) as sometimes sediments released c an clog the drain at the heater... if it does, just cap the drain and will be all set.

Also note, OLGA... changing ANODE rod is a great idea... will increase the life of your heater for sure!! (if you want to know more GLEE let me know).

If my answer helped please RATE THIS ANSWER by clicking on rate this answer at upper right or bottom of post. Thank you.

Thanks for your response. Most of the draining instructions tells me to close the cold water supply valve (but then if you do that then you only get a couple of buckets of water). My neighbor said he left his valve on and just left the hose on for 30 minutes! I just think it will be hard to get all the minerals out because they settle at the bottom of the tank (and the spout doesn't go that low). I have clear water coming out now but the knocking/firecracker sound still continues ;-(

OK... keep water on... see here, the DIP tube from the cold water inlet drops to near the bottom of the heater so it will stir the sediment plenty... AS LONG AS WATER TURNED ON while draining. Try that... say 4-5 minutes... bet things improve.

And glee... shut water off and drain about 10 gallons out (open hot water handle at sink somewhwere) if you decide to change the relief valve... BUT it will not help with the problem you are having right now.

Always a good idea to check temp. Here, your water heater should be set at 125 degrees or less... a candy thermometer may help here... just open hot water and test... what temp. is it set at? Let us know.