Replies

1. 
   DanH | Jul 12, 2012 08:26am | #1

   First thing it to make sure that the damn thing will fit, physically.  Not usually a problem when the heater is installed in a open, full-height basement or garage, but if it's crammed into a utility room, under some ductwork, you may find (like we did) that there's only one or two models that can be used.

   Your local water company should be able to tell you what the common water pressure is in your area.  But if the area is quite hilly and you're near the bottom of a hill then you may want to simply go out and purchase a pressure gauge and fittings for a hose bib (if you can't borrow something from someone), to check for yourself.

   Re the "bladder device" you're confusing two related items.  If you have a pressure reduction valve, or if your locality requires a backflow preventer ("check") valve, then you need to get an expansion tank.  With the PRV or the check valve, when water heats it can't expand back into the main, so pressure in the house plumbing increases.  This would lead to frequent "popping" of the temperature/pressure relief valve on the water heater.  To prevent this, an "expansion tank" -- a roughly 1-gallon tank with an air-containing bladder inside -- needs to be installed.  It generally SHOULD NOT be installed on the hot water line or near the water heater, to prevent hot water from entering the tank and speeding the degradation of the bladder.

   Your local water company, or the building department, should be able to tell you if a check valve is required.  The check valve is supposed to prevent backflow from your system into the main, on the theory that this can cause contamination.  This would be highly unlikely under normal circumstances, but can occur when, eg, a fire truck hooks up on the next block and your water pressure drops below zero.  But be sure to not confuse the check valve that may be required on entry to the house with the one that is almost certainly required on any new hose bib -- the latter creates no problem for water heaters.

   (But note that, even though a PRV or check valve may not be "required", based on local conditons/rules, if you're working with existing plumbing one may still be in place, requiring an expansion tank.)

1. 
   fassbinder | Jul 12, 2012 08:54am | #2

   Thanks for the info.

   Was just reading the pdf of the WH manual. Clarifies things nicely.

   Found a unit same size diameter and actually 7 inches shorter so should be ok there.

   If I was the only person in the house I'd really like to take my time and learn how to do this myself.

   Given time I don't think it would be too difficult to work out the connections.

   The joint sweating would be the only thing I'd be hesitant about. Especially if those additional items would be required.

   At least I was able to replace a few faucets and toilet guts without calling in help.

1. 
   fassbinder | Jul 12, 2012 09:01am | #3

   I'm wondering I should elevate this with some 4" blocks. The pan would be sitting on top of the blocks. It sure would drain better.

   Might be overkill though as long as the pan would be there anyway.

2. 
   Tim | Jul 12, 2012 01:21pm | #4

   Ideas

   For the pan (I have never seen a Code that required one, but as you stated, a good idea), consider a plastic pan in lieu of galvanized.

   A plastic pan intended for a WH will have a provision for a drain. Will require a 3/4" bulkhead fitting and some piping to the nearest floor drain. Make use of that provision if you can.

   If you hire the plumber, pay them to install the necessary items that they supply (and guarantee). Otherwise, if you go get the Home Depot made in China backflow preventer (for example) and it doesn't work properly, the plumber will rightly take no responsibility.

   I am an avid DIYer. If I'm doing it, I would be doing what you are - finding out everything (hopefully) that I need and asking questions. IF I'm paying someone to do a job, I let them worry about all the details. In your case, relax and let your plumber do the job and pay them to do it right (but, hold them accountable to do so).

   While another poster covered the generic details, be very specific about a "backflow preventer". This is not simply a check valve (or an anti-siphon device, as was also described). It is a very specifc UL/NSF rated appliance. Typically, these items are not available at homecenter/box stores, but only at a wholesale plumbing supply. IF available, "Watts" is a recommended brand name to look for.

3. 
   [email protected] | Jul 12, 2012 02:35pm | #5

   ETC.

   The catch pan is required under current code, and must drain to somewhere, such that it prevents damage to the structure if the tank leaks.  Not sure that is always possible on retrofits. 

   The discharge pipe from the temperature/pressure relief valve, has to go to within 6-inches of the floor, cant reduce in size, shouldn't have more than 180-degrees of bends, and can't discharge to the catch pan.  Again, this isn't always possible.  It is also supposed to discharge where the occupants will notice it is disharging. 

   The PRV is typically required if the static pressure is above 70-psi.  They function as a backflow device, and if you install one you should intall an expansion tank.  I keep my pressure valve set down to 50-psi, and didn't install one.  The tank, and rest of the plumbing is rated for 100-psi, the water doesn't expand enough to get the pressure that high. 

   I doubt your existing system has any form of a backflow device.  The water purveyor can tell you if you need one. 

   The current code requires a mechanical disconnect within 5-feet of mechanical devices to isolate them from the energy source.  So on an elecrtric water heater, we have started to install breakers, or locakable switches next to them. 

   Typically water heaters are installed with flex lines, and no soldering is required.  Ideally there are isolation valves on both sides of the water heater.  With the preponderance of single handle faucets, it is nice to be able to close down both sides, so that if you leave the cold water on while you work, someone doesn't inadvertantly send water back down the hot side, from a faucet when they try to get a drink.  If your current setup is hard plumbed, and doesn't have isolation valves, have the plumber put them in.  That way you can do the work yourself next time. 

     

1. 
   Tim | Jul 16, 2012 04:07pm | #10

   Which code?

   You state "The catch pan is required under current code." Which Code? And what revision is current for you?

   It is not required by the applicable Code where I live and work.

1. 
   [email protected] | Jul 26, 2012 12:14pm | #11

   The International code.

   In the IRC it is P2801.5.

4. 
   user-1116010 | Jul 13, 2012 10:25am | #6

   water heater install preferences

   I prefer to use an aluminum or galvanized emergency drain pan, they are durable and sturdy, and hold up better than a plastic pan when the water heater is located in a high traffic area. A gravity drain connection is not always available for the pan's discharge pipe, so in these instances I recommend installing an automatic  shut off valve. This device works with a moisture sensing probe that is mounted in the drain pan; when the probe gets wet it sends a signal to a plunger type shut - off valve that is connected to the water heater's cold water inlet pipe. These devices are pre - wired and connect to a standard 120 volt electric outlet.  This valve can help prevent a catastrophic flood.

   A thermostatic tempering valve should be installed on all water heaters, and they  serve multiple purposes. Water heaters should be set to maintain a minimum temperature of 140 degrees F to prevent the growth of Legionella. Higher operating temperatures can add a little more capacity during peak demand periods when combined with a tempering valve. The tempering valve will deliver consistent, safe temperature water, and some tempering valves will even shut down  when the water temperature exceeds the set point.

   The water heater location is important for proper maintenance. Access and clearance are needed for yearly inspection of the anode rod. The safety relief valve should be exercised annully and flushing the heater via the drain cock can add years to the tank's life..............................MikeL

5. 
   fassbinder | Jul 13, 2012 11:58am | #7

   Actually was able to talk with a county Inspector.

   He mentioned that a metal drain pan is only required for new construction, not for a refit..but you're really stupid if you don't put one in if you ask me. Not much over $15 at Big Box.

   Also, in  the neighbouring (big city) county the expansion tank assembly is mandatory but not in this county. He wasn't aware of any special gizmos that are typically required in my area.

   Still not sure if I should elevate the WH and its 22" pan on 4" blocks or not.

   Lowes will install it for $259. Sounded good enough for me. It's a real drag shopping for plumbers, so I'm not going to bother. Their WH seemed to get better reviews over the Home Depot model.

1. 
   florida | Jul 13, 2012 04:18pm | #8

   What's the point in hiring a professional plumber if you're not going to use his expertise?  Any competent plumber would know the answers to all your questions and intall your water heater correctly.

1. 
   fassbinder | Jul 14, 2012 10:42am | #9

   Exactly.

   If the particular job requires no particular expertise there's no need.