Re-use old hot water heater?

Old 04-14-15, 05:39 AM
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Re-use old hot water heater?

Based on some of the other comments I've seen this is may be a no-brainer, but I will ask anyway.

Our hot water heater is leaking and due to be replaced. There is actually another hot water heater in the basement that was in use when the house was divided into two flats (it was the heater for the upstairs flat). This second water heater has been sitting dormant for about 10 years since the house was remodeled and the upstairs flat got gutted. All the plumbing leading to it was disconnected but to be honest I don't know if it even got drained.

Do you think it would be safe to re-use this water heater?

Old 04-14-15, 05:43 AM
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You could clean it out and try it. 40+ yrs ago I bought an used WH for $10 and got good service out of it. Back then money was tight and I couldn't afford a new one. Would you be hooking it up yourself?
Old 04-14-15, 06:21 AM
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I would not risk it, buy a new one.
Old 04-14-15, 04:27 PM
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o If it fails soon you will have to go through the cost of installing again very quickly.

o If it was not drained then rusting of the tank keeps going, although slower compared with being at full hot water temperature.

o No telling what kinds of nasty bugs could be inside, and not easily killed off by bleach because the inside of the tank is quite rough.
Old 04-29-15, 07:16 PM
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Another thing you may want to consider, is that if you buy a new water heater now, you can probably still find an "old" style heater in the dealer's stock. If you try to reuse the used water heater, and it fails a year or so down the road, then likely you'll be facing buying one of the new (and more expensive) energy saving water heaters. The new water heater standards that went into effect on April 15 are resulting in water heaters that are considerabily bigger, costlier, and in many cases, more complex than the water heaters produced prior to April 15.
Old 06-07-15, 07:28 PM
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Yes: Here is how

Water heater is just a machine like any other. If it is intact and operable, why not continue to use it? First, flush it out inside. There is a drain and an inlet labeled "cold" at the top. There may also be a square or 'Allen key" plug head in the top...this may be the sacrificial anode that is used to avoid the effects of hard water on the shell...this can be replaced. I would pull it and examine it to see if it is used up. If not, simply re-install it (use teflon tape and pipe thread compound)) (also if the anode is in good shape that is an indicator the water heater is in pretty good condition). If it is used up, your local supply house should be able to order you a new one. Open or better yet, remove the drain valve. You want to flow a lot of water through the tank to help clean it out, so remove the valve and install a proper sise pipe nipple with a male hose bib thread to attach a garden hose to drain away the water and waste. Now, attach a hose fitting to the top 'cold" water inlet attach a hose and turn on the water with all the flow/pressure you have. You want lots of turbulence at the bottom of the tank to agitate any sediment at the bottom and flush it out the drain. Look to see what come out. It is likely to look like buff colored or reddish sand looking granules. Keep flushing until the water runs clean. Drain the water out, now tip the tank over on it's side and look at the bottom. check for rust, or obvious places water may have been leaking (you might see a white crusty spot). If clean, take a long screw driver or a long rod about 12" long x 1/4" and tap the bottom of the shell- avoid touching or moving the burner or any of the gas piping. Just gently tap around on the bottom. You should hear a metallic sound. Where you hear a dull thud sound when you tap, that's hard water sediment crust inside and it means the tank is 'rocked up" with hard sheets of thick lime stuck firmly to the sides and bottom and flue pipe. In spite of all your hard work, at this point, replace the water heater. That lime will insulate the fire from the water and it will be wasteful to use it energy wise. But, if you detect most places a good metallic sound, you are good to go. Probably 5 to ten more years of life in her. On the label you should be able to find if the tank is glass lined. If so, you are really good to go (most tanks now days are glass lined). Install a new hose bibb drain. Hook her up to the gas (or electric) service (know what you are doing there...if not call in a certified plumber!!!), make sure you safely and properly hook up the exhaust flue, water lines and new anode, you have a good unit. Oh, yes! Install a brand new T&P safety valve. Do not operate with the old one just for safety sake and peace of mind.

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