Page 1 of 2 12 LastLast
Results 1 to 13 of 24
  1. #1
    Join Date
    Apr 2007
    Posts
    46

    Losing hot water in showers after 15 minutes - need new water heater?

    Anyways here's the situation. Center hall colonial, about 2400 square feet. Three heating zones (1st fl, 2nd fl, basement). Basement zone is rarely used (if ever). Two adults in the home. Boiler is a cast iron WelMclain about 20 years old. I also have a SuperStor storage tank, I think AquaStor. The storage tank is about 18 years old.

    Anyways I am finding that recently when taking a shower, I am losing the really hot water after about 10 minutes, which means I have to continue to add more hot and less cold on the shower knob until eventually my body can take the "hot" water when turned all the way hot (no cold). I never used to have this problem. When I have the shower running and very little hot water left, I can check my kitchen faucet and i dont have hot water there either so i know its not isolated with the shower.

    Trying to figure out what the issue is. My oil company Petro already replaced the circulator pump for the water tank. That did not solve the problem. They are thinking the tank might have to be replaced, but how do I know it's actually the storage tank that's the problem? The boiler is reading 180 degrees so I don't think thats the issue.

    Looking for a solution that will give me tons of hot water. Should I replace this with another storage tank? Should I go with a water heater instead? What is the difference between a water heater and water storage tank? Don't they both hold and maintain water?

    If I go with a water heater, what brand should I get that's good? Don't mind spending a few extra bucks for something real good as I just dropped 300k in renovations to this house (added the second story). Should I go indirect (its not currently set up for indirect).

    And finally the SuperStor is currently run off electric as my boiler is oil. I don't have any natural gas available at the street, but I do have propane for cooking and one dryer. I could easily do propane for the water heater, however is propane cheaper to run vs. electric? My propane rates currently are $4.99 a gallon and my electric is about 20-22cents a kWh. The only issue with going propane is my propane tank outside is 50 gallons. 50 gallons of propane can last me the entire year for cooking / dryer (I can get away with only filling up once a year - which is why my propane rate is so high little usage). If I start heating my water with it, how quickly am I going to have to get fill ups?

    Also the heat in my house is done with hot water and slant fin baseboards. I dont have any issues heating the house as the house gets warm quickly.

    I am in Long Island NY so if there are any pros out there, feel free to reply to the thread or send a FM if you are local.

    Thanks

  2. #2
    Join Date
    Aug 2007
    Location
    Northern VA 38 degrees N by 76 degrees W
    Posts
    5,060
    does your boiler have a domestic water coil and you are using a stand alone storage tank?

  3. #3
    Join Date
    Jan 2009
    Location
    Keokuk, IA
    Posts
    5,520
    Maybe I can sum this up a little better. So you just put $300k into rennovations and added nearly doubled the size of the home... plus finishing the basement and didn't have the 20 year old oil boiler evaluated or upgraded?

    Did a engineer do any load calculation and determine how the pipe sizing and building heat loads would be affected? Unfotunately the focus is usually on making things pretty, then functional, then only when it's not comfortable does anyone think about HVAC.

    Not a personal criticism, just common in the HGTV modern rennovation world.


    Did the problem only begin once it started getting colder? Although you did note that the water temp was still 180F, so I suspect it's not falling behind, but I'll leave that to a boiler expert.

    It just sounds like something changed. If the circulator was repalced, I wonder if the new one has the same flow rate? or maybe the one that failed was already oversized to increase flow and the new one matches the design spec.

    I wonder if the thermostat that turns on the pump is set correctly. Maybe it's not comming on as soon as it did with the old circulator. By hte tiem it comes on your'e already "behind the curve" so to speak and the water has cooled off. the old heat exchanger tubes just can't catch up.

    I'm going to stop here and leave it to a boielr expert.

  4. #4
    Join Date
    Apr 2007
    Posts
    46
    Quote Originally Posted by motoguy128 View Post
    Maybe I can sum this up a little better. So you just put $300k into rennovations and added nearly doubled the size of the home... plus finishing the basement and didn't have the 20 year old oil boiler evaluated or upgraded?

    Did a engineer do any load calculation and determine how the pipe sizing and building heat loads would be affected? Unfotunately the focus is usually on making things pretty, then functional, then only when it's not comfortable does anyone think about HVAC.

    While the size of the house was doubled, we did not double the usage as we are still only two people and I did not want to upgrade the heating system with hope that some day they will bring gas to the street and I would upgrade to natural gas then.

    What's the point of upgrading the heating system that runs on oil when I really want to get off oil?

    As I said before the money is not the issue as I don't mind dumping money into a water heater... IF it needs to be upgraded. I wasn't going to upgrade unless I had to.

    The problem with the hot water was starting before it got colder out.

  5. #5
    Join Date
    Apr 2007
    Posts
    46
    Quote Originally Posted by second opinion View Post
    does your boiler have a domestic water coil and you are using a stand alone storage tank?

    The boiler I believe has it's own coil for domestic water, but I don't think the boiler itself has a storage tank. There is an expansion tank attached near it.

    The SuperStor storage tank is a separate unit.

  6. #6
    Join Date
    Mar 2005
    Location
    Suppy NC
    Posts
    4,513
    the flo rate of the tanklees coil may have been changed or the coil is scaled up and need to be replaced
    you may have a broken element on the tank so when electric only it is only heat the top or the bottom of the tank instead of both

    an inderect as long as installed correcty willl serve IMHO better then any water heater could as long as the boiler can handle the extra load

    just have the tank checked and then decide the route you want to take

  7. #7
    Join Date
    Jul 2004
    Location
    Massachusetts
    Posts
    6,837
    The solution for "Tons" of hot water would be an indirect water heater attached to the existing boiler. It'll run a few thou for the installation but you should be able to stand in the shower all day long once installed.

    Now back to the problem. Not a lot of good troubleshooters when it comes to DHW problems. The first thing to establish is whether the tank ever actually reaches set point in between hot water demands. If the circulator for the storage tank is operating the entire time, then the tankless is likely coated with mineral deposits and in need of either replacement or a flush. Or you can skip all that and go to the indirect without further ado. On the other hand, if the circulator actually stops, and the aquastat is accurate, then I'd look into a broken dip tube in the heater. When cold water is introduced to the storage tank when you're showering, it needs to be directed to the lowest part of the tank so as the hot water at the top of tank is used, the cold water at the bottom continues to increase in depth. After a few minutes, the cold water reaches the aquastat, which turns on the circulator and starts the burner. If the dip tube is broken off part way down in the tank, the cold water will mix with the hot water at midlevel in the tank, thus depriving you of a long shower. Or you could just skip all that and go with an indirect water heater. For you and the missus a simple stainless steel 40-gallon will give prodigious amounts of hot water.
    If YOU want change, YOU have to first change.

    If you are waiting for the 'other guy' to change first, just remember, you're the 'other guy's' other guy. To continue to expect real change when you keep acting the same way as always, is folly. Won't happen. Real change will only happen when a majority of the people change the way they vote!

  8. #8
    Join Date
    Apr 2007
    Posts
    46
    I have a feeling the tank itself is just old. Many people i talked to say these tanks last 10-15 years and i am on year 18 now.

    Can someone recommend a decent indirect water heater? Brand?

    While its just myself and my wife I want somethingore future proof once kids come into the equation. I have plenty of space where the tank is. What size should I go say for a family of four?

    Also should I stick with electric or is it worth going with propane? If I go propane can I eventually convert it back to gas if I ever convert the boiler itself to gas?

  9. #9
    Join Date
    Mar 2005
    Location
    Suppy NC
    Posts
    4,513
    wielmclain makes a very good ID the gold 40, 60, 80
    as i said as long as installed properly you are going to be hard pressed to run out of hot water
    had the gold 40 in my old house for five years and four back to back showers not once ran out

  10. #10
    Join Date
    Apr 2007
    Posts
    46
    How do I know if I am getting an actual indirect system when they install this thing? What am I looking for regarding the installation when people are saying "as long as it's done right".

  11. #11
    Join Date
    Jun 2004
    Location
    St Paul, minnesota
    Posts
    1,224
    An indirect water heater will have a coil piped to your boiler with a circulator with a priority control on it (priority control will shut off your comfort circulator and start indirect circulator + bypass any outdoor reset to run boiler up to 180 degrees whenever there is a domestic hot water demand). Also a properly setup indirect only loses about 1/2 to 1 degrees per hour in standby. standard water heaters have much higher standby losses. superstor is made by amtrol is a very good indirect heater. you should have a mixing valve connecting your hot and cold line. could be defective or like others said a broken dip tube also.

  12. #12
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,171
    Post pics of your indirect, and its piping to the boiler. Problem may be the boiler, or a control.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  13. #13
    Join Date
    Apr 2007
    Posts
    46
    Just an update, had my HVAC guy over that did my CAC. He mentioned that my boiler was definitely undersized after adding the second story. He said I have a 3 stage boiler and I really should have a five?

    Anyways he said since the SuperStor was getting its hot water from the coil in the boiler, the coil in the boiler was probably the issue... possibly along with the hole in the rod or whatever was inside the storage tank.

    He said going with an indirect would at least eliminate the coil in the boiler until it comes time to upgrade the boiler (as I really don't want to upgrade the boiler right now). So I went with a Wel-McLain Plus 80 Gold Indirect. Thing is a beast. No issues now. Wasn't a cheap job... had to drop a few grand. But still worth it.

    Now I just have to hope my boiler will last long enough until I can eventually get gas.

    Thanks everyone.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event