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Help me diagnose no hot water problem

bdl
bdl Member Posts: 28
Woke up to no hot water this morning. Trying to diagnose where to start. Have a SuperStor indirect water heater fed by gas fired steam boiler. For the most part the system has been ok, since long ago I spent a bit of time selecting out proper steam vents with help from here.

In the past couple of days I noticed some odd sounds I think coming from the circulator, which seems to be a small Taco 3 speed circulator. It's painted green, so I think it is cast iron. Of course the part number is on the bottom, so it is not easily visible. The system is plumbed in 3/4" line, in other words there are line reducers at the boiler and the hot water tank. I realize this is not optimal for flow. Putting your hand on the line, it just doesn't feel like there is much flow going on.

In series and before the pump is a 3/4" cast iron Keckley Wye filter. This wye filter is in a terrible place for cleanout. Very hard to get a decent wrench on it. I can open the petcock on the wye filter and some water comes out, but it's not a lot, just a very low flow, best described as continuous series of drops. This wye filter screen seems to clog a lot. It may be the root of the problem. Last time it clogged up, I had to get a plumber in to remove the screen. Even for him, it was awkward. I'd really like to find a slightly coarser filter, but Keckley does not offer one, or my search did not reveal one.

The circulator motor case is hot. The water is hot before the circulator. Eventually the water gets hot on the other side. However, the return line from the tank has not gotten hot. It is just barely warmer than stone cold. Obviously the return won't get hot instantly, but I'd expect a little more temperature rise. This leads me to believe there's a flow problem in the wye filter screen (extremely likely), the circulator, or maybe even in the old SuperStor. What else could it be?

Might be a red herring, but I did hear some noises coming from the tank this morning. I'm at a loss at how to describe it. Might be a combination of tapping, mechanical or bubbling. It's low pitch though and doesn't sound exactly like any of those descriptions. I recorded the sound (via a video), but the file is a little large 27MB. Don't know if I can attach it.

Any advice would be appreciated! I checked and found that a cartridge is nearly as expensive as the whole circulator! (And the cartridge is backordered until January.)

Comments

  • Ironman
    Ironman Member Posts: 7,076
    Well, it sounds like a flow problem, and it could be that the circulator is bad or that the strainer is clogged - or both.

    Is it a stainless or bronze circulator? If it’s cast iron, it should be replaced with a non ferrous circulator.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • bdl
    bdl Member Posts: 28
    Cleaned out the strainer - it was full of junk. Fortunately it was not installed by a gorilla, so I could get it off. Managed to dump a lot of water on the floor - insufficient number of ball valves in the system. :( 4 gallons came out that I caught, more on the floor. Yuck.

    Pretty sure it's cast iron a circulator. Circulator motor is warm/hot. The temperature on both sides of the circulator is vastly different. I will check if the circulator is getting power, although the heat of the cartridge case is a pretty good check. Circulator is a Taco 0015-MSF3-IFC. Maybe the IFC is clogged? Seems to be a place where junk could collect? Guess I have to remove the circulator to see if the impeller even moves, or the IFC is filled with stuff. Fortunately, there are ball valves on both sides of the circulator.

    Don't know if the capacitors go wrong, but there is one in the circulator wiring box.

    Now the wye discharge valve flows a lot. At least that's better. Still no hot water.
  • bdl
    bdl Member Posts: 28
    Is it better to try removing the cartridge to see if the impeller moves, rather than removing the whole circulator? I don't have replacement gaskets at the moment.
  • bdl
    bdl Member Posts: 28
    I'll answer that. It's relatively easy to open up the cartridge. There was some iron crud in there which I could scrape out and clean with a paper towel. Turning the impeller, which is part of the cartridge was movable but didn't seem that smooth.

    If I understand correctly one is supposed to use o-rings on the flanges, rather than gaskets. Mine have gaskets. In any case, I wasn't sure how to disengage the flanges without damaging things. Was unable to crack open the flanges on the exit port. I did open the input port valve and dark murky water came out. Cleaned it all and put it together. No joy, either the exit IFC is plugged or the cartridge is defunct. Still no flow.

    I'm going to order a whole circulator unit, can't fool around with this.

  • Ironman
    Ironman Member Posts: 7,076
    Four bolts hold the motor to the volute. You don’t have to take it loose at the flanges to access the cartridge. 

    There’s an O ring that seals the motor to the volute. If your careful not to tear it, you can re-use it.

    If you’re ordering a new circulator, make sure that you get a stainless steel one.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • bdl
    bdl Member Posts: 28
    Unfortunately the stainless version is more than 3 x the cost, and the warranty is the same 3 years as the cast iron unit. I'd love a stainless one, but not at that premium. If the stainless one lasted 3 x as long, I'd consider it. The old cast iron unit lasted a while, a lot longer than 3 years. There was no visible corrosion in it, just crud from the boiler. I ordered the cast iron version. Hope I won't regret that.
  • mattmia2
    mattmia2 Member Posts: 7,165
    It should be stainless or bronze because the water in a steam boiler is open to the air so it gets fresh oxygen from the air to corrode a ferrous circulator. Using a cast iron circulator in that application may void the warranty.
    Ironmankcopp
  • Ironman
    Ironman Member Posts: 7,076
    bdl said:
    Unfortunately the stainless version is more than 3 x the cost, and the warranty is the same 3 years as the cast iron unit. I'd love a stainless one, but not at that premium. If the stainless one lasted 3 x as long, I'd consider it. The old cast iron unit lasted a while, a lot longer than 3 years. There was no visible corrosion in it, just crud from the boiler. I ordered the cast iron version. Hope I won't regret that.
    The laws of physics will prevail over the laws of economics every time.

    Not only should you not use an iron circulator in that application, you also should not use a wet rotor circulator where the bearings are water lubricated.

    Why do you make the assumption (based upon the warranty) that both circulators will last the same time or that the next iron circulator will last three years?

    Bite the bullet and get the right tool for the job or you’ll be right back at the same place soon. And it could be at the most inopportune time. 
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    PC7060kcopp
  • bdl
    bdl Member Posts: 28
    I appreciate the advice I'm getting, that's why I've posted. I've received a lot of great ideas in the past from the Wall, especially in helping me balance out my steam system.

    I'm not that versed in hot water, as you can plainly see. I just want some hot water. I'm getting some advise of what not to do. I need to know what to do. For the short term, I need some hot water. So I'll spend $100 to get myself out of a jam for now. In the summer, I can address the bigger problem.

    Honestly, I don't know if the existing circulator is even the right size for the job. It may be undersized. You know, installed by a professional knucklehead. Our hot water hasn't been the greatest over the years, it runs out too quickly and takes too long to reheat. Taking too long to reheat is a flow problem, which might be better served by re-plumbing to 1" and getting a higher flow circulator unit. US Boiler has an app note on selecting the right size circulator. If I understand it, one needs a lot higher flow rate than one would think.

    Specifically, what kind of circulator should I get for this application? I'm currently running an Independence gas fired steam boiler with an indirect tank (SuperStor). I can get the model number off the boiler if required. Currently the pipe is 3/4" to and from the SuperStor. I want to boost the loop flow rate and make the loop more tolerant to boiler crud.

    Above, I was told not to use a water lubed motor, which seems to rule out Taco circulators. So what is recommended?
  • Ironman
    Ironman Member Posts: 7,076
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Larry Weingarten
    Larry Weingarten Member Posts: 2,782
    Hi, A thought here is to use an inexpensive stainless pump to get you by. Perhaps other solutions will come, but in the meantime, it seems Ebay has some inexpensive stainless pumps with similar flow characteristics to what you have now. Here's one to look at: https://www.ebay.com/itm/263319279418?hash=item3d4f0d573a:g:U90AAOSwwHFZn6SZ

    Yours, Larry
  • Peter_26
    Peter_26 Member Posts: 127
    bdl said:
    Of course the part number is on the bottom, so it is not easily visible.

    Doesn't this mean that the circulator is installed in a position the manufacturer does not recommend if he can't read the label? Could that be the reason for failure?
  • Ironman
    Ironman Member Posts: 7,076
    Peter_26 said:
    bdl said:
    Of course the part number is on the bottom, so it is not easily visible.
    Doesn't this mean that the circulator is installed in a position the manufacturer does not recommend if he can't read the label? Could that be the reason for failure?
    No, it’s the wrong circulator for the application.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • bdl
    bdl Member Posts: 28
    Peter_26 said:

    bdl said:

    Of course the part number is on the bottom, so it is not easily visible.

    Doesn't this mean that the circulator is installed in a position the manufacturer does not recommend if he can't read the label? Could that be the reason for failure?


    No. It means that I failed to read the part number on the motor casing which was in plain view. The circulator was installed in the correct orientation according to Taco.
    Peter_26
  • bdl
    bdl Member Posts: 28
    Ironman said:
    Eek! Now that's an expensive circulator. Wish I was working, but I'm retired. Out of my league cost wise. Anything else that's would be suitable? Can't afford the best anymore. Is there a tier beneath this that still is ok?
  • Ironman
    Ironman Member Posts: 7,076
    edited December 2021
    No, unfortunately there’s not.

    It’s not a matter of “good, better or best”. It’s simply a matter of the right or wrong one.

    A bronze or stainless 2 or 3 piece circulator is the only correct option.

    Of all the pumps that are manufactured and sold, your scenario is very likely less than one in a thousand. Why would a manufacturer make multiple options available under those circumstances when one will do?

    You can’t use anything that’s water lubricated or iron because of the amount of sludge and rust that’s in the bottom of a steam boiler. The pump that I posted is actually made for an open domestic water line. No one makes a pump that’s specifically designed for your application; this is the one that’s best suited to it of what’s available.

    I can appreciate your situation, but once again, this is a matter of physics and physics will not be swayed by economics.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • bdl
    bdl Member Posts: 28
    Well despite recommendations, I replaced the circulator with the same one - just to get something going. Found an online supplier that had it in stock. It seems the circulator pump runs. The hot water goes into the indirect heater, SuperStor SSU-45 but so far the exit water is still cool even after 4 hours. The boiler is full. However, reading the SuperStor manual, I see the plumbing to and from the boiler is undersized, ie. it is 3/4 copper, but the tank is 1".

    When the circulator started, it seemed that the pipe wasn't full. By that I mean the top of the pipe had air, and the bottom had flowing hot water. After a while, the copper conduction eliminated the temperature differential. Not sure if this is considered "normal".

    I think there still are problems with this system, and I'm guessing it may be the 9 year old SuperStor, the skinny plumbing, and probably the circulator is undersized and the wrong kind too.

    I'm about to throw in the towel on this. Wish I could get someone that would fix this right.

    Went downstairs - pressure relief valve on the SuperStor has blown. I have shut everything off, water is coming out of the blowoff on the HW heater. Turned off valves and supply lines, turned off boiler. What a mess. I have HW though, but most of it is on the floor.
  • Jamie Hall
    Jamie Hall Member Posts: 20,443
    Let me make sure I have this really straight here.

    You have a new circulator, which is connected via 3/4 inch pipe from a connection on a steam boiler on to a Superstor and back to the steam boiler (it really doesn't matter whether the circulator is on the supply or the return).

    Is that correct?

    And at the present moment the pressure relief valve on the Superstor has blown and is still open. The circulator is off and valves close. The boiler is off.

    You have hot water.

    When you initially started the circulator, the pipe didn't appear to fill.

    Is this all correct?

    If so. OK. The pressure relief valve should not have blown. Either the Superstor overheated, which is highly unlikely, or overpressured. Is there an expansion tank on your hot water system? Is the valve to it, if any, open? Since the only way that the Superstor can have overpressured is the it heated, but the water had no place to expand.

    If anything, it indicates that the circulator was able to move enough boiler water to heat the water in the Superstor -- which is good, at least so far as it goes.

    However, it may not have heated it as fast as it should have? That plus the comment that the pipe didn't appear to fill makes very little sense. If the pipe comes from the boiler to the circulator, and then the circulator pushes it to the Supersor, there is almost no way that that pipe wouldn't be full, at least up to the water level in the boiler, and the circulator should have been able to push the water up the additional height.

    However, there may be a serious obstruction. I believe you mentioned a filter or strainer? Is it on the intake to the pump? If so, have you checked to be certain that it isn't clogged?

    There is another possibility: if the circulator is pumping from the Superstor back to the boiler, and the coils in the Superstor are higher at any point than the boiler water line, they may not have been purged. Indeed, the circulator may not be able to get enough suction to purge them, at least not in any reasonable length of time.

    Would please comment on the above comments? Then we can explore this further.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • mattmia2
    mattmia2 Member Posts: 7,165
    you pulled the screen out of the strainer and cleaned it, right?
  • bdl
    bdl Member Posts: 28
    Lot of questions. I've just been through a bit of a nightmare.
    Yes, to the first question.
    Yes, the pressure relief on the superstor blew. I then turned off the boiler, and started turning off valves, including the ones surrounding the circ. I turned off the hot water valve. Still water coming out through the blowoff. When it stopped there was 2" of water on the floor. Started pumping out the water out of the pit.

    Slowly turned on all the valves, and refired up the boiler. Still pumping water out of pit, but blowoff had closed. After about 4-5 minutes had gone by the blowoff opened again. Shut down system again, closing valves. Water was continuing to come out of blowoff. Looked up and saw the cold water line was sweating and feeding the bottom of the tank. No cold water shutoff nearby, but traced back to a shutoff valve and closed it. Water stopped coming out of blowoff. Disconnected circulator power. Closed circ valves. Opened other valve for boiler. Fired up boiler again. Half the house has no cold water right now. Dammit, why didn't that heating guy put in a more convenient shutoff!

    Wye strainer was horribly clogged, but was cleaned out totally prior to new circ install. Water runs at full volume thru the wye, on both the drain part and the thru part. I tested that. Answering the pipe question: Pipe was hot on bottom, but not on top in the beginning. I thought it would be hot everywhere from the get go, but it took a little while to warm up everywhere.

    Circ is at the boiler pushing water to superstor. Superstor coils are at the bottom of the tank. They are roughly the same level.

    Pretty clear I need a new blowoff. I think the expansion tank is due for replacement, the bladder leaks down over a long period of time. The valve is open. How long do these expansion tanks last? I think the date code on mine ends with 99.

    At least I have heat tonight, so I don't have to make an emergency plumber call. Those calls are pricey. The pit is finally pumped out now.

    SuperStor coils are below the tapping on the boiler, hope that is good.
  • bdl
    bdl Member Posts: 28
    mattmia2 said:

    you pulled the screen out of the strainer and cleaned it, right?

    Yes, before installing the circulator. It was a mess, needed a scraper to get rid of some of the crud inside the wye housing. Flushed it all out, clean as a whistle. It was the first thing I checked before replacing the circulator. Right, check the cheapest thing that can go wrong first?
  • Jamie Hall
    Jamie Hall Member Posts: 20,443
    You need a new expansion tank. That much is clear... you also now need a new pressure relief valve. It's not worth trusting one which has been operated.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • bdl
    bdl Member Posts: 28
    Yes, it is time to replace the expansion tank. My inadvertent test on the pressure relief valve showed me they don't hold a second time. I've had the blow off valves fail before (not this one, a different one). They just let go for no reason. Tomorrow is another day. At least I avoided an emergency plumbing call tonight.
  • Ironman
    Ironman Member Posts: 7,076
    The relief valve on the water heater heater is a temperature/pressure relief. It may be dumping because the water heater got too hot.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • mattmia2
    mattmia2 Member Posts: 7,165
    where is the relief valve that is blowing off? is it on the water heater or is it on the boiler?
  • bdl
    bdl Member Posts: 28
    Water heater! There's less than 1.5 psi on the boiler.
  • STEAM DOCTOR
    STEAM DOCTOR Member Posts: 1,564
    mattmia2 said:
    It should be stainless or bronze because the water in a steam boiler is open to the air so it gets fresh oxygen from the air to corrode a ferrous circulator. Using a cast iron circulator in that application may void the warranty.
    I highly doubt that warranty would ever be honored. Circulators are not designed for steam boilers. Some are better, some are worse. No matter which circulator is used, it's an out of the box application. There are issues with the crud. There is also the issue that you are running the circulator with close to zero pressure. And the potential for steam flashing in the circulator.  
  • STEAM DOCTOR
    STEAM DOCTOR Member Posts: 1,564
    Fwiw, I have seen cast iron circulators,  used in this application,  lasting 10+ years. Of course, I have also seen them go bad within a year or two. Just my 2 cents. 
  • bdl
    bdl Member Posts: 28
    This feels like one horse shay, where everything is falling apart at once. My favorite wholesale plumbing house got bought up an closed. Of course, none of the big box stores have what is needed. I remember that there's a wholesale place nearby. I'll pay them a visit. I was able to buy a radiator spud wrench from them a while back.

    If there's a broken wire somewhere, like in an aquastat, do these systems fail staying on? Just wondering why the over-pressure happened. I'm assuming for the sake of discussion that I will fix the expansion tank and pressure relief. What else can cause over-pressure in the hot water heater?
  • Jamie Hall
    Jamie Hall Member Posts: 20,443
    The overpressure was, almost certainly, simply the result of a failing expansion tank. Nothing else has to fail for that to happen.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • bdl
    bdl Member Posts: 28
    Found a local wholesale plumbing store today. They got me set up with the correct pressure relied valve and a new potable water expansion tank. After muttering, hmm more like cussing about the placement of the expansion tank, finally got it off. Apparently a person with 8 foot arms and 3 foot pipe wrenches installed it. Replaced the tank and pressure relief valve. Put all the valves and whatnot in their original positions and fired it up. No leaks, no drama. Just glorious hot water and my first shower in 6 days. :D Have heat and hot water, what could be better!

    Along the way to solving this problem, found some pretty weird plumbing/installation choices. Have to fix some of them when not in the midst of the heating season. Thanks for everyone's help, greatly appreciated. Still going to research the choice of circulator. I heard what was said, and take it seriously. There might still be an effective solution that is less expensive. However, I am prepared to replace Tacos as needed for the moment. One thing I did was to date the circulator, the expansion tank and the pressure relief valve with a sharpie. I wonder how long these parts will last.
    mattmia2
  • mattmia2
    mattmia2 Member Posts: 7,165
    The relief valve is usually a hardware store item though you might need a longer probe for an indirect.

    Menard's stocks a lot more professional stuff than home depot and lowe's.
  • bdl
    bdl Member Posts: 28
    There are no Menard's around here. Menards is a midwest based store, I'm in the northeast. Closest one is a 20 hour drive away. Wish there was something better than HD and Lowes around. But have to say, my guy at the local wholesale plumbing supply house came through, so I'm happy. The pressure relief valve probe is 8" for my indirect HW heater. At least for now, I'm sorted.