Hydronic heating. Both general water(potable) and radiant heating(non-potable)

allencrown

For the past couple days I've had a issue come up so its been an education on hydronic heating on a full sprint.
My place has one gas water heater (Bradford White)to heat both the radiant floor (heating) and the normal consumable water (faucet, shower, appliances etc...). I have contacted B&W and provided my model/serial of the tank. (Which has been discontinued) the B&W tech said that this tank does not separate the heating water and potable water
From the exterior of the tank it looks to be a closed system but after speaking with B.W. tech internally he said it is an open system. Circulating both waters together. What am I missing here?? Does this mean that I am consuming my non-potable heating water?

Jamie Hall

Most likely... what is the model number of the unit? None of the current models of BW residential water heaters I find separates.

Gordy

Unless there is an external heat exchanger than yes they are mixed together. Not good.

allencrown

Thank for the help!
Model # M2CTW50TIOEN10
Serial # TC5147009
I attached pic as well

allencrown

Thanks for the help!
I have attached pic of the tank system. I don't think there is a heat exchanger.. Can you tell from the pic? Also there is not a timer on the system to circulate the heating water (when not in use) so the heating water that sat for 6 to 7 months got circulated when I turned it on.. correct?

Gordy

You can separate them with a brazed plate heat exchanger that separates the two systems.

Gordy

Correct. What is temp setting on the water heater? Is there a mixing valve for domestic, and or the radiant?

Gordy

Also have you heard of legionella?

allencrown

Thanks Gordy,
Currently, I am a property manager of 99 aptartments and I live in one of them. All of these units have this exact same hydronic system. (See the problem) I believe when these were installed in 99' 2000.And the city passed inspections with a closed loop system. Not an open system as we have here. I'm trying to get that confirmed.
I say *currently* i am a property manager b/c I approached my supervisors with this issue and they wouldn't even give me the time of day or even cared to inspect the possible problem. Not only could this effect our current residents but over 15 years of past residents. (Yikes)
I'll let you know if I still have a job next week.

Gordy

I would approach this from the legionella standpoint. Read up on it it is a concern. Especially if the renters have resiptory issues, and weakened immune systems. Elderly, and children more susceptible.

This does not affect one household, but many as a complex.

What is the temp of the waterheater?

Your absolutely certain there is no external heat exchanger?

allencrown

I know, its very unfortunate. I hope I am wrong with everything, but if I am correct, who knows what would happen. (That's why I am reaching out for additional information)
Water temp gauge is currently at 120' (but this goes up and down from day to day from 100' to 125' - I think the gauge itself is not working properly)
And YES! I am absolutely certain there is no external heat exchanger.

Gordy

Legionella just loves to thrive in that temperature.it does not like above 135. To use that temperature would require mixing for both domestic, and radiant heat.

Gordy

Plenty of info here, and Google on legionella concerns. Do a search on this site.

Jamie Hall

If that is an open system -- which seems far more likely than not -- and if it is running at the temperatures you quote, it is a disease disaster waiting to happen, especially Legionella. Unless you need the job, and can convince your supervisor to start fixing things yesterday, may I suggest a quick exit?

hot_rod

BW still makes the CombiCor. Which is a tank with internal HX for heating loops.
Depending g on age and condition, maybe start a replacement plan with Combis.

Plate HX would be an option, but requires a stainless pump and possibly yearly flushing and de liming of all those HX. Depends on water quality and amount of DHW used