Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Dormant commercial water heating system

Tinman Member Posts: 2,804
I was sent a picture of this mechanical room and asked to do the start-up on the domestic hot water heaters. I know this system has been down for a while but nobody has been able to tell me for how long. I was told there is pressure in the water heaters and that they haven't been fired in a "while". I'm more than a little reluctant to just dive right in without having some answers. 90% of my business is hydronic heating systems. I won't be the guy responsible for people getting seriously ill or worse from Legionnaires Disease. I'd really like to know how some of you guys would approach this? How do I go about having the water tested? I was able to get a lot of useful information on OSHA's website but I'd like input from fellow contractor's also.
Steve Minnich


  • icesailor
    icesailor Member Posts: 7,265

    There's a "history" to this. It looks like it was never ever turned on or run.

    Like is everything signed off by the AHJ's? Is there some "Issue" between the Contractor, the owner, architect or the AHJ's? Is there a CO?

    If it isn't signed off and you touch it, someone might have something over you without your permission. Like going on an unfinished job without the permit holders permission and working on a job without a permit. A job isn't finished until the final is signed off. The file for the building is a public record. You have a right to see it. I'd be looking it over. 

    IHO, it might be worth time for a discrete trip down to see the AHJ's to try to get the straight scoop on what is going on. From appearances, there doesn't seem to a gang of hackaroos have worked there. Something is up.

    If you have to post photos of something your concerned about, you probably should be and your instincts tell you so.

    Been there, done that.

    If some builder/developer/contractor owes someone a pile of money and they won't come back until paid, you could be getting someone off the hook by getting the job finished and a final inspection done. More than once, I had some smarmy POS try to get me into something like that. Not without the full story.
  • heatpro02920
    heatpro02920 Member Posts: 991
    edited March 2014
    Water testing can be simple or difficult

    free tests are given at most plumbing supply houses that sell water filters...

    I asked Bradford White a while back about this, what should I do to startup a tank that has been sitting with stagnant drinking water...

    I was told to flush and drain the tank, then to pump in 1 cup of household unscented straight bleach per 10 gallons of water storage, so a 50 gallon tank needs 5 cups, then fill the tank and with a utility pump circulate the bleach/water through the tank for 2 hours, then let the tank sit, after 24 hours fluch and drain the tank again....

    I did this by putting a 5 gallon bucket with a sump pump and a tube to the drain filling the bucket while the pump pumped it through the t & p tapping...

    The tanks I did were twin 50 gallons and they had a noticeable smell to the water, after I cleaned them, no smell, no complaints, no one got sick... I had the water tested out of the tank by the "free" method from the water filter company and it came back a1 ok... I didnt have it tested prior but it smelt funny and slimy to the touch....

    the other method---

    I do a lot of building maintenance and foreclosed house wints and de-wints, so when I need a documented test I use 1 of two labs, but they charge and take a while, one is through aquascience, and the other is aquatec labratories {or something to that effect}...

    But If I were you and I have done a few times, the bleach and flush works very well, and for indirects or hx's vinegar is good...

    When it comes to water quality and safety, common sense goes a long way, the test, taste, and feel logic works well... If it feels slimy and or smells funny test it dont taste it...

    As far as getting everything else started, I would treat that like a new install, combustion efficiency test, check the flues, check the temps, ect...
  • icesailor
    icesailor Member Posts: 7,265
    Bleach @ Bacteria:

    If its just safe water in the system your concerned about, and the system has been sitting dormant for a very long period of time, there are other considerations. It is kind of a aerobic (lives in air) and anaerobic (lives without air). Li lives in slime inside pipes and lives in shower heads or cooling tower water.

    If everything is on the up and up with this place, and you want to get it going, I'd take a great big air compressor and blow down the entire system. And blow a lot of air through the system. It will get rid of any slime and critters that reside there. The air/oxygen will kill any anaerobic bacteria. The swirling air and water will polish the insides clean. If the water is off, you can test for leaks. If you're really serious about doing a fine thing, after blowing out all the water (and you WILL blow it all out), note the water meter reading before you fill it and then what it is when you are done. Compute your bleach strength on the amount of water in the system. You can connect a handy utility water pump to a drain on the water service as close to where it comes in to the building and mix bleach and water in a 5 gallon bucket or two and get all that bleach into the system. Let it sit. Blow it all out with air, then, fill and flush to your desires.

    In the case of chlorination disinfecting, not enough is worse than none at all.
  • Jamie Hall
    Jamie Hall Member Posts: 21,115
    And just to add

    to Ice and heatpro's comments (both excellent, naturally!) you also want that chlorinated water to be in there for a while and circulate -- circulation is very important, as otherwise there is the possibility of some location having some nasty in it and depleting the chlorine without your being aware of it.

    I would want an absolute minimum of 15 minutes contact time with a strong chlorine residual at the end of that time.  Half an hour to an hour would be much much better -- and the water should smell like a YMCA pool at the end of it.  Chlorine test strips and tablets are available for swimming pool maintenance, and are a cheap and easy quick guide.

    You may find, even after you blow the system out and rinse it, that you need more chlorine that you might initially think.  Make sure that your chlorine residuals at both the beginning and end of the circulation procedure are at least 3 ppm.

    Then drain and refill and circulate some more -- and have the water tested at some reliable lab. for every bug they can think of.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • icesailor
    icesailor Member Posts: 7,265
    edited March 2014
    Good Chlorine Points:

    Good points. One of the advantages of first blowing out the system with air is that you can usually measure it fairly accurately. If you really shock the system with adequate chlorine, you don't have to worry so much. A few years ago, I took on a large Museum like restored brick house with copper radiant heat in the ceiling. I wasn't concerned with that. But just with the Potable water. The previous plumber had been pumping trailer anti-freeze in the system for at least 5 years when I took over. The owner told me at least 30 gallons a pop. He was afraid something would break. I blew the house out with my small air compressor. I couldn't use the Weil-McLain TT Indirect for a air storage tank because draining the water and leaving the heat side would have broken the tank. I never had a single problem draining with air and refilling with water in the Spring. But it was at least 3 years before the alcohol smell of the anti-freeze was completely gone when I filled it. The water would also foam out of faucets with aerators.

    Its a really accurate way to measure how much anti-freeze any heating system needs. To much is a waste and too little is dangerous.

    Another thing on bleach. Cheap store brand is just as good as the expensive stuff. But be SURE to look on the label and be sure that it is 5.25% Sodium Hypochlorite and not the cheaper 3.5% stuff. It makes a big difference.
  • Tinman
    Tinman Member Posts: 2,804
    Thanks guys

    The education never ends. Lots of useful information. And thanks to you too, Kurt.
    Steve Minnich
  • Tinman
    Tinman Member Posts: 2,804
    I took a look...

    at the job yesterday and aside from the water quality, a stuck recirc pump, and temp settings set too low; I think it looked pretty good. We're having the water analyzed by a company that specializes in such things and providing a bid for flushing and the other repairs/adjustments. I've attached a picture of some funky looking water and a quick piping schematic I drew up. Piping looks top notch. Water, not so much.
    Steve Minnich
  • icesailor
    icesailor Member Posts: 7,265
    Green Water:

    That funky green water could be of a concern. Was the system Anti-freeze' d when it was turned off? That green water looks like ethylene glycol but it should mix easily with the water. Does it have a smell? Polypropylene Glycol is usually red and Ethylene is often yellow greenish color. Do you have a refractometer that you can test that green stuff with? It will react to both types of anti-freeze. If you could gather enough of it, you could use an el cheapo floating ball type but maybe not. If its ethylene glycol, I'd be doing some serious water/air flushing to get that stuff out. If you get any foaming in faucet aerators, you haven't got it all out.