GE (Rheem) 40 Gal Gas - Water cools when not used

Discussion in 'Water Heater Forum, Tanks' started by doc_u, Mar 9, 2011.

  1. doc_u

    doc_u New Member

    Messages:
    11
    Location:
    SF California
    I have a 40 Gal GE Gas WH which is now about 10.5 yrs old, came with the house 3 yrs ago.
    Naturally this WH had a 9 year warranty which is now expired.

    The symptom I am experiencing is that the temperature of the water can vary quite widely.

    In the morning, the water is barely hot enough to take a shower.
    30 mins after the shower, it's much hotter.

    Seems to me that the Thermostat/Gas Valve is not functioning properly, and needs to cool excessively before it turns the burner back on. Thermocouple was replaced about 1 yr ago due to pilot not staying lit. No issues with the pilot now.

    The valve/tstat is a Robertshaw R110RTSP and the online pricing runs about 180 at the low end.

    When I can get a BigBox WH for 500-600, or a BW online for 900-1000, does it make any sense to put that much money into a new valve?

    Tried flushing it out over the past weekend, didn't get a huge amount of sediment, just some particles of sand and crap, and got pretty hot water right after it refilled and reheated, but the next morning it was lukewarm again.

    Any suggestions gratefully accepted.

    -doc
  2. Redwood

    Redwood Master Plumber

    Messages:
    7,450
    Location:
    Connecticut
    You are probably on track with the old thermostat getting lazy.
    A 10 1/2 + year old GE is probably not worth investing $180 + into although I may be wrong and the thing may decide to go on for 20 more years. I wouldn't bet on it!

    Big Box? I'd avoid the blue one that is a horror story in it's own right...
    At Orange you can take a chance on another GE maybe the luck will be similar and maybe not.

    I'm a fan of Bradford White myself...
    Since your last water heater they have come out with FVIR (Flammable Vapor Ignition Resistant) water heaters.
    Bradford White & Lochinvar share the same system design and win the race hands down!
    Rheem, Ruud, Richmond, & GE share the same design and come in second place
    With the AO Smith family (AO Smith, American, State, Reliance, Apollo, GSW, Polaris, and John Wood, also includes Whirlpool label ) not finishing the race...
  3. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,246
    Location:
    Land of Cheese
    If you did fix it there is still a good chance that the tank may start leaking anytime now and then you will have to buy a new one anyway.
    I see 40 gallon gas heaters on sale for 250-300 on a regular basis here in the Midwest.
  4. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,980
    Location:
    NW Ontario, Canada
    What is the temp it shuts off at now? Have you tried adjusting the temp up a notch (without risking scalding) to see if it minimizes the spread?

    My old State tank held the temp much more consistently than the GSW that replaced it. While not as bad as you describe, the White Rodgers temperature control has a noticable spread between the on and off limits. It seems like after it sits a while, it only takes a couple gallons of draw for it to come on and bring it back up to temp. I often wondered if it was some new conservation feature but your 10 1/2 year old tank probably would pre-date such. I think my State tank lasted about 11 years.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,636
    Location:
    Cave Creek, Arizona
    quote; When I can get a BigBox WH for 500-600, or a BW online for 900-1000,

    I would like to sell you, or anyone else, water heaters all day long at those prices.
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,013
    Location:
    New England
    You might try just turning the thermostat from one end to the other a couple of times, then return to your preferred position. Won't hurt, and it might help.
  7. doc_u

    doc_u New Member

    Messages:
    11
    Location:
    SF California
    Yes, I have tried adjusting the T-stat and it seems to work to adjust the "initial" temp of the water, but the same issue happens after it stands for awhile. Don't really want to crank it way up (hottest temp read out of the kitchen faucet was 122 F) since I have two kids under 5...

    Did some more research last night (again proving that this forum is a great resource) and located a couple of BW's that should work. Found some significantly cheaper Rheem models but apparently cannot get these shipped to Calif due to the enviro-nazis.

    Now looking at the BW M45036FBN (low alt) online for about $570 shipped with no tax and the 6 year warranty. Add a hundred for the 10-year warranty. That's the .62 EF version, the MI5036FBN is about $490, same deal on shipping, etc. Probably go with the higher EF since the gas co will kick down $30 or so, but I think I will skip the extra warranty. If anyone in the SF Bay Area needs one of these (M45036FBN) I can get an even lower price (430) if I get two...

    Got to measure tonight to make sure the 50 gal units will fit where the old 40 gal is now, and maintain appropriate clearances...

    As far as install supplies I was gonna get two flex hoses (stainless, made for hot water heaters), a straight through 3/4" ball valve to replace the leaky cold inlet valve, and a couple of insulated nipples.

    What else am I missing? (assuming I have the needed copper pipe/fittings, torch, solder, and skill to sweat a few joints). Should I replace the exisiting gas flex line also?

    Thanks for all the help and advice. I'll try to post a few updates and maybe some before/after pics.

    -doc
  8. Redwood

    Redwood Master Plumber

    Messages:
    7,450
    Location:
    Connecticut
    Ah you are in one of the Ultra Low NOx required areas...
    That explains the pricing...
  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,013
    Location:
    New England
    SF probably requires earthquake strapping and a flexible gas line as well. Good idea to not reuse the existing flex gas line - bending it again after it's been there awhile might cause it to crack.
  10. doc_u

    doc_u New Member

    Messages:
    11
    Location:
    SF California
    Yes, I'll definitely be strapping it to the studs per the codes. The current strapping job is kind of half-assed.

    I also noticed a few things when I went to measure and plan the install of the new tank.

    The existing WH has the T&P valve on the top, exiting at 59". It makes a loop through a jumble of galvanized pipe and exits the wall at 57 1/2". The BW that I am looking at normally has the T&P valve on the side at 50", so I am apparently going to have to rework that drain somewhat. Looks like crap the way it's done now anyway.

    T&P Piping.jpg

    Apparently the new WH can be ordered with the T&P valve on top, so I'll contact the vendor I'm considering and find out if that is available fairly quickly. If anyone has a local contact (San Jose) for a BW, I'd be interested as long as the price is reasonable. Was going to stop at one of the local supply houses and see if they have any "scratch and dent" models also.

    The positioning of the piping for the cold inlet, along with the connection for a no-longer-used water softener, means that it may be slightly more difficult than I thought to replace the inlet valve. On the other hand, I could trim the pipe back, remove the tee to the softener apparatus, and then install the new valve. The tee in the pic below is before the inlet valve and leads to the aforementioned softener connections.

    Cold Inlet.jpg

    Another post will cover the gas piping. I am leaning towards getting a pro to handle this for me, and the next post will explain why...

    Thanks again to all...

    -doc
  11. doc_u

    doc_u New Member

    Messages:
    11
    Location:
    SF California
    Gas Piping questions

    The answer is yes, since the inlet on all the 50 gal tanks is 1/2", so this removes most of my other questions about the gas line.
    Will replace the flex line anyway since I don't know its age or condition.

    -doc

    Attached Files:

    Last edited: Mar 13, 2011
  12. doc_u

    doc_u New Member

    Messages:
    11
    Location:
    SF California
    Called the supplier and 4-5 week lead time on the tank with the top T&P, so I'll just drop straight down from the T&P valve, then take a 90 to the wall to and thru to another (outside) 90. I'll probably put a union on it so it can be dissassembled when needed. I can do this with copper instead of the frankenstein of galvanized I have there now.

    -doc
  13. doc_u

    doc_u New Member

    Messages:
    11
    Location:
    SF California
    The after pictures

    Here's the final result of the WH replacement.

    Overview.jpg
    The new water heater, BW 50 Gal.


    TPR_layout.jpg
    A slightly less goofy TPR valve piping.
    Anyone know if there's an issue having the outlet of the TPR valve at this angle?
    It's just a little below 90, for the downslope to the (now-lowered) copper in the wall that drops to the outside outlet (a copper 90).

    TPR_closeup.jpg
    Another view of the TPR valve piping. There was probably a better way to do this, but it works and doesn't leak.

    NewGas.jpg
    New arrangement of the Gas manifold, adding a drip leg or sediment trap for the furnace, and getting rid of the galvanized 90 and nipple that someone used when they put in the furnace.


    Supply.jpg
    New config for the water lines. Removed the old, leaky gate valve and installed a full-port ball valve.
    Had to replace the tee before the valve since it got damaged during removal of the old gate valve body.
    The other leg of the tee feeds cold to the rest of the house. Since the valve I got was a F-F, and so was the supply hose, I used a brass nipple to join the two. This was the only leak I had, so I disassembled it, wiped off the dope and applied tape instead. It no longer leaks.
    Last edited: Mar 27, 2011
  14. doc_u

    doc_u New Member

    Messages:
    11
    Location:
    SF California
    A couple more of the final install.

    Overview-Bottom.jpg
    This shows the overall layout of the lines, etc.

    WH-Trap.jpg
    Added a sediment trap for the WH in accordance with code.
    About halfway through the job I decided I liked the pipe tape way more than the pipe dope in the tube.

    Glad this job's finished. Now need to return the stuff I didn't use to HD and OSH.
    (Already had to turn the stat down to A as B was just WAY too hot, especially with young kids in the house).
    Last edited: Mar 27, 2011
  15. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    If I see the photos correctly...in the original, does the TP discharge line step down to 1/2" at a reducing elbow near the wall??? And in the new one does it do the same thing??
    That is not acceptable.
    The straps are supposed to be in the upper third and lower third. You might just be in spec on that.
    I didn't know you could but BW at retail.
  16. doc_u

    doc_u New Member

    Messages:
    11
    Location:
    SF California
    No, even in the original install (which I was not a part of) there was no reduction in size.
    The new one uses 3/4" CPVC and is 3/4" all the way to the run in the wall (3/4" copper), which I shortened and 90'd out to a 3/4" copper threaded coupling.
    None of the couplings reduce size. I actually used the 3/4" copper pipe I removed from the wall for the various bits and pieces I had to add on the supply side, and for the stub out at the top of the 90 out of the wall.

    Yes, the straps are (barely) in the right areas, but I had a few issues to deal with there.

    Is there any issue with the TPR valve being mostly sideways? I wasn't able to find a reference in the code that was explicit about this, and since they use top-mounted ones all the time, I figured it would work.

    As for the BW, there's really only one place on the net that sells them, a quick google search will confirm.
    I don't really want to post the name here, as they may not be in the good graces of this forum.

    -Doc
  17. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,013
    Location:
    New England
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