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Installing A New Hot Water Heater Tank – Part 3


Installing a New Hot Water Heater Tank is a multi-part series article, broken into Part 1, Part 2, Part 3 and Part 4.



In Part 3 of the article, I describe the steps I used to drain and disconnect the hot water heater tank.

Draining Water from the Old Heater Tank

Step 3.2 – Drain hot water

  1. To minimize the chance of scolding while disconnecting the tank, turn on the cloth washing machine and run a hot wash cycle to reduce the amount of hot water in the tank (remember, gas supply is off at this point any cold water entering the tank will not be heated).
  2. When the wash cycle is complete, turn off the water main (main shutoff valve is usually located near the water meter).
  3. If the drain spout is very close to the tank body, you need a hose extension to redirect the water into a bucket. One quick solution is to “borrow” a short piece that connects the hose reel to the water hose bib.
  4. connect-drain-valve-to-hoseFor safety reasons, most tanks have their drain spout handles removed (so kids can’t turn it on and get scolded). Simply use a flat-headed screwdriver to turn the drain spout.
  5. Make sure to leave this screwdriver near the spout as you will need to turn it on and off frequently.
  6. Do not walk away while the water is draining, even for a minute.
  7. After draining about 15 gallons of water, shut off the drain spout;
  8. open-pressure-relief-valveOpen the pressure relief valve located on the top of the tank. This will allow air to get into the tank as the water is drained.
  9. Drain the remaining hot water.
  10. Open the lowest faucet (usually an outside faucet), then open all faucets located from the highest floor to completely drain the water.
  11. Draining the entire pipes will allow efficient soldering as even a small amount of water near the joints will make soldering impossible.
  12. After draining, remove and set aside drain pipes attached to the pressure relief valve to be re-used later

Step 3.3 – Detaching electrical ground wire

  1. remove-ground-wiresBecause brass fittings (e.g. water shutoff valve, etc.) do not conduct electricity, a jumper or ground wire is usually be found near them.
  2. Using a flat-headed screwdriver, unscrew both lugnuts and set them aside.

Step 3.4 – Detaching vents

In most cases, hot water heater exhaust vent is connected directly to the chimney. In some instances though, an exhaust vent stack is shared between the furnace and hot water heater. Second scenario is what I had so a large section needed to be removed in order to remove the tank.

It can be rather time consuming to re-assemble multiple 45 degree “flex” joints. Do yourself a favor and carefully follow these steps:

  1. mark-vent-pipesCarefully mark each pipe sections with a sharpie (line drawn on both moving parts to indicate proper alignment as well as part numbers – like A-B, C-C, so forth);
  2. The flue covering for the hot water heater tank should be replaced (new one usually comes with the new tank) so discard the old one.
  3. Check and clean the pipe interior.

Step 3.5 – Detaching the gas and copper pipes and joints

TIP: Working with a gas line is very dangerous. Please seek professional help if you have never done this kind of work and/or if you are unsure of your skills!

In step 3.1, I placed a masking tape around two pipe sections and marked them to ensure that these pieces are not disturbed during the removal process. Although I will do a leak test at the end of the projcet, this visual aid certainly helps as I work on the gas pipes.

To remove gas steel pipes, use a medium sized pipe wrench and a pair of large pliers;

  1. Dis-assemble the gas union by turning the pipe wrench and pliers in the opposite direction (see picture) ; Use of medium sized tools minimizes the risk of over-torquing parts; discard this piece;
  2. Label each each pipes as the are removed.
  3. When all gas pipes are removed, take a wire brush to clean the pipe threads.

To remove copper pipes (for water), use either mini or 2″ pipe cutter.

  1. Double-check to make sure that water supply has been turned off;
  2. Survey the copper water pipes to determine the optimum location for cut.
  3. In my case, I decided to cut the hot water pipe very close to the old tank; and for the cold water, I made cut just above the water shutoff valve (tip: 1/4 turn shut off valves allow water to flow more efficiently).
  4. Use a mini pipe cutter to make cuts and have some rags ready to mop up any remaining water in the pipes.

cut-copper-pipesTIP: When cutting copper pipes, always start out by LIGHTLY scoring the pipe. After several turns, apply more pressure until pipe is cut. Otherwise, you may end up with multiple scores on the pipe which may pose problems down the road. It’s best to rotate the pipe cutter in both directions for a clean cut.

Step 3.4 – Remove the old tank

Look around the tank to make sure that all attachments have been severed or disconnected. Although the tank is mostly emptyr, sediments can add the extra weight. If possible, have someone to help you to remove it or if you are working alone (like me), at least use a convertible hand truck.

NEXT >> Installing a new Hot Water Heater Tank – Part 4


Installing A New Hot Water Heater – Part 4

Monday 16th of July 2012

[...] Installing a new Hot Water Heater Tank – Part 3 [...]

Installing A New Hot Water Heater – Part 2

Saturday 14th of July 2012

[...] Installing a new Hot Water Heater Tank – Part 3 [...]