Renovation 4th Edition

by Michael Litchfield

  Tee

  A plumber should also be willing to peer

  through the vent thimble with a flashlight and

  mirror to check the chimney’s interior. All man-

  Mission T-150

  Tub-shoe gasket

  trap adapter

  ner of debris can accumulate in the bottom of a

  Tub shoe (waste ell)

  chimney—from soot to nests—and that debris

  can block a chimney, hamper flue draft, and pos-

  Chrome tailpiece

  sibly force carbon monoxide into living areas.

  Trap arm

  The National Fire Protection Association sug-

  P-trap

  gests annual chimney and flue inspections and

  whenever a new type of burning appliance is

  vented into the flue, but inspection is really not a

  If the tub drain is not accessible, plumbing codes require that joints be

  plumber’s job. The Chimney Safety Institute of

  glued together to prevent leaks. To join the tub tailpiece to the trap

  America offers a state-by-state listing of chimney

  assembly, use a Mission T-150 trap (11/2-in. tubular to 11/2-in. pipe).

  P R O T I P

  Don’t accept water heaters

  whose boxes are bashed or torn.

  water-heater elements are sensi-

  tive. If the box has been handled

  roughly or dropped, anode rods,

  liners, or valves may have been

  damaged.

  a shower wall at rough-in. a pressure-balancing antiscald Finishing touches. To avoid marring the surface of a

  valve (which mixes hot and cold water) is at the bottom of chrome shower arm, insert a sliding-jaw pliers handle into the assembly. The smaller valve above it controls water

  the pipe and turn it into final position. When the

  volume. Note the nail plates to protect the pipes.

  bathroom is painted and all brightware is installed,

  remove the protective plastic from the shower walls.

  plumbing

  351

  Turn off the gas first—the stopcock

  will be perpendicular to the gas line—

  before removing an old gas-fired water

  heater. use an adjustable wrench to

  disconnect the gas coupling.

  once the gas line is disconnected,

  attach a hose to the drain at the

  bottom of the water heater and drain

  the tank.

  a new gas-fired water heater in mid-installation. The red

  lever-handled shutoff valve on the cold-water pipe is

  required by code. after installing the TPR safety valve,

  plumbers will reattach the vent pipe.

  services with certified staff (check out its website

  To vent

  zzzzzz gas-Fired water heater

  at www.csia.org).

  Above all, installers should follow the water-

  Hot-water outlet

  heater manufacturer’s installation instructions

  3/4-in. flexible copper or

  closely to ensure a safe installation and to safe-

  stainless-steel lines

  guard the unit’s warranty should the water heater

  fail to function properly.

  Draft hood

  draining the old water heater. The specifics of

  Shutoff valve

  disconnecting power or fuel to the old unit will

  Cold-water

  vary, depending on whether the water heater is

  inlet

  TPR valve

  gas fired, fuel-oil fired, or electric. Once the

  installer has disconnected the fuel or power

  Brass nipples

  source, the water should be shut off and the tank

  drained. Typically, a hose will be attached to the

  drain valve at the bottom of the tank. Using a

  pair of pipe wrenches, unions (if any) on the hot-

  Alternative

  side outlet for

  and cold-water pipes will be taken apart; if there

  3/4-in.

  TPR valve

  are no unions, pipes will be cut 6 in. to 12 in.

  discharge pipe

  above the top of the heater—or a couple inches

  discharges

  above the cold-water shutoff valve—by means of

  outside.

  hacksaw or a wheeled cutter. Caution: Recipro-

  cating saws aren’t used because the vibration

  may weaken nearby pipe joints and cause leaks.

  installing the new heater. If the unit is gas or

  oil fired, the installer will disconnect the draft

  hood and vent pipe and either wire them up out

  Gas-supply

  of the way or set them to one side. As noted earlier,

  shutoff

  the plumber should inspect the vent pipes. If the

  hood or pipes are rusty or corroded, they should

  Strap water heater

  be replaced. When the old tank is empty, it can be

  Flex connector

  for gas

  Thermostat

  in earthquake regions.

  walked out of the way. Be mindful of sharp edges

  352 Chapter 12

  on the newly cut pipes and the area around the

  P R O T I P

  old tank. Note: If codes require strapping the

  unit, steel straps should be bolted to the wall

  when replacing a water

  behind before putting the new unit in place.

  heater, put unions and lever-

  Finally, if the pad beneath the old tank is in poor

  handle ball valves on both the

  condition or badly tilted, consider installing a

  hot- and the cold-water pipes.

  new prefab concrete pad. Then the new water

  Code requires a shutoff valve only

  heater can be walked into position.

  on the cold-water pipe, but hav-

  Making connections. What the installer does

  ing them on both can make peri-

  next depends on the size and condition of the

  odic drainage and repairs easier.

  pipes, what fittings are present, and, of course,

  what type of water heater it is. There’s no single

  right way to assemble pipes, but the photos on

  the facing page show a typical installation in

  progress for a gas-fired unit. There are 3⁄4-in.

  Tankless water heaters are more

  brass nipples screwed in the tank inlet holes,

  expensive and more complicated to

  flexible stainless-steel lines, sweat-to-threaded

  install than tank-style heaters

  because tankless models require

  male adapters, valves, and (at the top) 3⁄4-in.

  expertise in plumbing, electrical

  rigid-copper trunk lines exiting to the upper

  wiring, and gas fitting. The yellow

  floors. Flexible stainless-steel or flexible copper

  tubing entering at right is a CSST

  supply lines are highly recommended for top-of-

  gas line.

  tank connections: Female nuts on both ends

  make them easy to disconnect for future repairs.

  installing a TPr valve. Many new water heaters

  have preinstalled TPR valves. If there is none, the

  plumber will install a TPR valve into the threaded

  outlet atop the unit or in a side outlet a few inches Instal ing a Tankless

  down from the top of the tank, lightly coat the

  Water Heater

  TPR valve’s threads with pipe compound, and

  Tankless water heaters, also known as on-

  then use
a pipe wrench to install the valve. Next,

  demand, instant, or flash water heaters, don’t

  the plumber will install a discharge pipe into the

  have storage tanks for heated water. When some-

  TPR valve’s threaded outlet. The pipe may be gal-

  one opens a hot-water faucet and water begins to

  vanized or rigid copper—but not plastic—and

  flow through a tankless heater, a flow sensor

  must slope downward. The discharge pipe should

  P R O T I P

  ignites the unit’s burner, and a heat exchanger

  be terminated about 6 in. above the floor, at a

  honeycombed with coiled water pipes heats up

  safe location where hot water won’t scald anyone almost instantaneously. When the faucet or

  In areas that lose power peri-

  if it discharges.

  shower valve shuts off and the water stops flow-

  odically, a tank of hot water is a

  Note: Threaded pipe fittings should be coated

  ing, the sensor shuts off the burner.

  nice thing to have on hand. If

  with pipe compound or wrapped with Teflon tape

  you live in an area where the

  Tankless water heaters are generally more

  to ensure a positive seal.

  power goes out regularly, think

  complicated and more expensive to install than a

  twice about going tankless.

  Final steps. The plumber will check the water

  traditional tank heater but, on the whole, are less

  heater for level, shim the base as needed, and

  expensive to operate because there’s no energy

  tighten the earthquake straps, if any. When all fit-

  wasted keeping a tankful of water hot around

  tings are connected, turn on the cold water to fill

  the clock. In other words, tankless water heaters

  the tank. Open the hot-water faucets to expel air.

  consume energy only when hot water is needed.

  When the tank is full, water will gush from the

  About the size of a suitcase, tankless units are a

  faucets. At that point, shut the faucets, and

  great favorite when space is tight, too.

  reconnect the fuel or power source as specified in

  Their other great draw is that properly sized

  the manufacturer’s instructions. Note: If the

  tankless units never run out of hot water.

  installer disconnected the bonding jumper wires

  (Endless hot water is not free, of course: Linger

  from the hot- and cold-supply pipes, those wires

  too long in the shower and you’ll squander those

  should be reclamped now to ensure proper

  operating efficiencies.) As a rule of thumb, a

  grounding for the house’s electrical system.

  tankless unit with 140,000-Btu input will suffice

  for a one-bath home with one or two users; a

  190,000-Btu input should do for a two-bath home

  with two to four people. (These figures assume a

  unit with an energy factor of 0.82 or greater.) If

  plumbing

  353

  your home has three baths and up, a pair of tank-

  less water heaters located close to points of use

  Tankless? gO WiTH a PrO may be a better call. Qualified installers can help

  Installing tankless water heaters is best left to

  calculate an optimal size for your home.

  licensed professionals. as most units are gas

  loCaTIng The unIT

  fired, installations require gas, plumbing, and

  electrical expertise. Because of safety issues—

  If you locate a tankless water heater as close as

  especially the correct installation of TPR

  possible to the fixtures that use the most hot

  valves—most local codes require permits for

  water, you will lose less heat in transmission. In

  replacing or installing water heaters. moreover,

  new construction, that’s often easy to do. In reno-

  almost all manufacturers make their warranties

  vation, however, new tankless units are frequently

  contingent on a professional installation.

  installed near the site of the old tank-style heater

  that’s being replaced—primarily because pipe

  (Tankless water heaters average $1,000 unin-

  hookups are already there.

  stalled, so they are an investment worth protect-

  Before deciding, however, consider what

  ing.) Lastly, because tankless units are wall

  connections your new water heater needs. Most

  hung, clearances and venting details are particu-

  tankless units require 3⁄4-in. water pipes, so if

  larly exacting.

  your old heater has only 1⁄2-in. water lines, that’s

  one less reason to use that location. If your tank-

  less heater is gas fired (as opposed to electric),

  it will require a 3⁄4-in. gas line. Tankless units

  have greater Btu input requirements than tank-

  style water heaters. Electricity is rarely a problem

  be-cause cables are easily routed and gas-fired

  units need only 110v to run fans, sensors, and

  the like.

  Venting can be problematic, though, if you

  hope to use an existing exhaust vent. Whereas

  some tankless heaters have separate intake and

  exhaust pipes, many others have a single concen-

  tric direct-vent pipe—a pipe within a pipe—to

  supply fresh air and exhaust combustion gas.

  That pipe will have an optimal pitch to carry off

  combustion condensation; see installation

  instructions. Lastly, tankless models vary accord-

  ing to whether they can be installed inside or out

  and how close vents may be installed to operable

  windows, eave vents, and so on.

  ouT wITh The olD,

  In wITh The new

  If there’s an old tank-style water heater, turn off

  electrical power and shut off the water supply to

  the tank. Use a voltage tester to be sure the power

  is off. Drain the tank, disconnect electrical con-

  nections, and cut the hot- and cold-water pipes to

  remove the old tank. If the old heater had a draft

  hood and exhaust vent, remove them, too: Most

  tankless models use concentric vent pipes.

  Whether you are replacing an old water heat-

  er or installing a new one from scratch, you need

  five things: (1) a route for a vent pipe and an

  opening to the exterior, if you are installing the

  tankless unit indoors, (2) tie-ins to 3⁄4-in. water

  pipes, (3) an electrical outlet for the unit’s power

  Plumb and mount the water heater. Just visible to the right of the unit are

  cord, (4) a gas line if the unit is gas fired, and

  existing copper water pipes—a convenient place to tie the tankless unit into

  house lines.

  354 Chapter 12

  Connecting to the underside of a tankless water heater is

  Sweating copper leads to valve assemblies is also easier

  easiest before it is mounted. Here, threaded stubs get an

  beforehand. In the foreground, the (red) hot-water

  application of pipe dope and Teflon tape; the stub at right assembly is being soldered. When soldering, heat the

  (a hot-water outlet) has a union coupling attached.

  fitting, not the pipe. V
alve assemblies (valve kits) save

  time by combining fittings, including unions, shutoff

  valves, and drains.

  (5) a sturdy place to wall-mount the unit—

  the water heater. Because PEX will melt when

  whether 2x lumber or, say, a 5⁄8-in. plywood panel. exposed to open flame, it must not be directly

  Review the installation instructions. If space

  connected to gas- or oil-fired water heaters and

  is tight, do as much work as you can before

  must be kept away from some types of flue pipe.

  mounting the tankless unit. For example, install

  After connecting water pipes, flush the lines to

  tees on existing supply pipes—so you can tie in

  dislodge any debris that may have collected dur-

  This takeoff atop a tankless unit gives

  the tankless unit’s cold-water intake and hot-

  ing the installation.

  a good cross section of a concentric

  water outtake pipes—and make a cutout for the

  Gas connections performed by a licensed gas

  direct–vent pipe. air for combustion

  unit’s vent pipe, if needed. Using flexible corru-

  fitter/installer are similar to water-pipe connec-

  is pulled in through the outer pipe;

  gated stainless-steel tubing (CSST) for gas pipe

  tions. A 3⁄

  exhaust gases are expelled through

  4-in. union fitting joins the gas line to a

  and flexible PEX for water-supply pipe will be

  threaded stub on the underside of the heater.

  the inner one.

  easier to route in a renovation—if they are

  Galvanized and black steel gas piping need a dirt

  allowed by your local building codes.

  leg (sediment trap), a short leg of vertical pipe

  just upstream from unit connections, to act as a

  sTurDy mounTIng,

  cleanout. The gas line should also have a shutoff

  solID ConneCTIons

  valve. Check all gas-line connections for leaks by

  Test-hang the tankless heater to make sure there

  are adequate clearance distances and room to

  make connections. Before mounting the unit,

  pros often preassemble hot- and cold-water shut-

  New gas

  leg

  off valve assemblies. Apply pipe dope and Teflon

  tape to the threaded stubs on the underside of

  the unit’s housing, and screw on a pair of union

  couplings. If you are working with rigid copper,

  this is also a good time to sweat (solder) pipe

  leads to valve assemblies, as shown in the photo

  at top right. Then attach a TPR valve to the out-

  take (hot-water) valve assembly.