Antifreeze Contaminates Domestic Water

Jeff_27

One of my techs went out on a service call today. He found the circulator on a boiler was changed last night. The pressure on the boiler went to 60 psi. The relief valve only wept, but the boiler water w/ anitfreeze got pushed through the auto fill valve. Now the customer's water is contaminated. We're in the process of changing the relief and the fill valve as well as installing a check valve.

Has this happened to anyone else out there and what did you do? Did you have the water tested? Who'd you call? We have no idea what was used for antifreeze. Hopefully, whoever filled it used the proper inhibitor. The customer has no idea who or what installed the antifreeze. He bought the house only recently.

Thanks in advance.

George_10

I will check with

our tech director when he returns. In the meantime, could the HO ask the old home owner who serviced the system when they were there. It would certainly help to know what was in the system before this happened.

Jeff_27

Thanks ... waiting.

No contact with previous owner.

George_10

Here is our answer to your problem.

Lets start with the first problem which would be bacterial contamination. Since the boiler water was very hot this water was probably sterilized. So that leaves chemical contamination from the glycol. If it was ethylene you will have more of a potential problem. The solution is to thoroughly flush the system through every water outlet in the house and let them run for couple hours. This includes not only the faucets, but the dishwasher, the washer, the showers and cleaning sinks etc. Also we would suggest the HO use bottled water for several days so that further flushing will be done through normal use. Your flushing should continue until you have no odor, smell or color in the system. If it was propolyne glycol you have less of a problem. That is why I suggested trying to reach the previous owner and see if they know who serviced their system.

Any residual after all of this should be well below the toxic levels. But to be sure, I would contact the glycol company if you find out what was used.

We also suggest the installation of a backflow preventer with atmospheric vent to prevent this from happening again.

Mad Dog

Where was the backflow preventor that should have

been installed? Why didn't the relief valve blow? I hope you changed it to a 30 psi one. It all depends on how the ho is reacting or overeacting. I wouldn't get crazy, but i would flush the heck out of all the domestic lines for at least 30-40 minutes. If they are concerned, they should bring in a water testing outfit. Just make sure you document everything you did and didn't do AND get signitures. Excellent advice george - use bottled water for now. Mad Dog

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George_10

You should have no taste either when you are finished.

scrook_2

old installation...

preceding code requirement for backflow preventor?

Odd the relief didn't lift, junk it and install a new one.

I'd go for flush to drains of all fixtures, starting w/ closest (plumbing wise) to the boiler and working out, including outside hose bibs, refrigerator ice makers, dishwashers, washing machines, etc. in addition to sinks and other fixtures. You could 'guestimate' the length and dia of the runs to each fixture and the flows thru the airators, showersheads, etc, so as to have some idea of how long to run them for a couple changes of water in the lines. You might also drain & refill hot water heater if you suspect some got to it before flushing the hot water fixtures. Then, if concerned, take representive water samples for test, though it should be fine w/ a sufficient flush.

Jeff_27

Thanks, guys. I'll let you know how we make out. We changed the relief and fill valve (combo backflow). The old expansion tank (barrel type) was full. We flushed the system and they're good to go. They are drinking bottled water for the next few days until a testing company can come out and test it. Thanks, again.

Jeff