Indirect hot water

mark_20

Anyone ever hear of a plumbing inspector failing an indirect hot water tank because the heat exchnager is not protected with the potable water. It happened to a guy I know in PA with a brand new Heat Transfer Super Stor. Has anyone ever seen one of the heat exchangers leak in a tank. I am putting a similar system in my home and wanted any info I could give to the inspector to help him understand it is not a safety concern (at least I hope it isn't)

eleft(retired)_5

Indirect

If there is a safety issue I think millions of us are in danger.
Idle chatter ruined many a business!
If it does leak the potable side pressure will blow off the relief on the boiler. 50+psi vs. 12psi. Be the water, which way would you go?
Do you believe the inspector doesn't know that?

al

jim lockard

Thanks

Al for a wonderful working example of high pressure going to low pressure. Lets see if the inspector can figure that out.

eleft(retired)_5

pdf

It's UL listed, Print this out for the inspector.

good luck, al

mark_20

The guy this happened to is an experienced in hydronics and he did everything he could to convince the inspector it was ok. He got codes from other states and counties as well as explaining the physics just as you did. He ended up eating the tank and controls and put in a regular tank and lost the respect of his customer. ust another example of how plumbing and hydronics use many of the same tools and material but really are two different animals.

heatboy

I have dozens.......

of single wall heat exchanger indirects in Pennsylvania and New Jersey. Even commercially in PA where Labor & Industry yield serious power, there has never been an issue. That's not to say some little burg can't supersede code. Sounds like it could be a local guy with the JW syndrome. I would fight that, for sure.

hb

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S Davis

Double Wall Heat Exchangers

In the Puget Sound area of washington state some jurisdictions require a double wall heat exchanger on indirect fired water heaters and some do not it doesn't make any sense, you just have to get to know where they want a double wall so you can put the extra cost into your bid.

S Davis

S Davis

Double wall heat exchangers

In the Puget Sound area of washington state some jurisdictions require a double wall heat exchanger on indirect fired water heaters and some do not it doesn't make any sense, you just have to get to know where they want a double wall so you can put the extra cost into your bid.

S Davis

Firedragon_4

Better check the code,

it's becoming more of the norm than the exception! I'm finding out everyday that many of our best ideas are 'not approved'.

Some in fact are listed and approved my somebody, but if the locals (state included) have not approved it look out!

The state inspector here in MA says he won't allow any new unit where the heating system and domestic mix unless it's approved by the Board of Plumbing including double-walled, FACT! In plainest terms if the Commonwealth doesn't know you, you're illegal!

jwade55_3

In Allegheny county

(Pittsburgh) the grand wizards of the plumbing board have deemed that all indirect water heaters be of the double wall variety. We have had meetings with them to dicuss this, and all of our customers have been made aware of this, as well as the fact that HTP has such a tank available.

J

Earthfire

what is the difference

as to leak potential between a in boiler domestic coil and the coil in a indirect? What justification is there to allow one and not the other? Maybe I is dense, but I see no difference as to leak risk or effect.

Billy_3

In MA

I have never had a problem with an inspector using a superstore or any indirect heater. If it is approved they can't fail it.

Mark Eatherton1

Clean water act....

is what is dictating the change to dbl walled HX. Denver passed the same law. We found that the recovery of the dbl walled tanks were WAY to slow to handle even the lighest of back to back demands. We even had to go back after final inspection and change the tank to a single wall just to keep a couple of families in hot water.

Not sure about your jurisdiction, but in Denver we were able to get the City to agree to the use of a pressure differential controller/cut off "system". Their fear is that IF the heat exchanger does fail AND there is a negative pressure on the potable water system that there is a CHANCE that water of questionable character could back flow into the potable water distribution system, thereby contaminating a main water distrubtuion system.

We explained that the chances of this sequence of events occuring were slim to none, but they didn't hear us. Backflow prevention is based on a one in a million chance occurence. If there IS a 1 in 1,000,000 chance, then it needs to be protected, according to the powers that be.

Anyway, the differential pressure device monitors the pressure difference between the potable water and the boiler water. If the two come to within 10 PSI of each other, a pair of solenoid valves on the indirect supply and return lines are supposed to close, thereby eliminating the chance of a cross connection and back siphonage.

We are required to pull a permnit for each and every one of these "systems" that we install. A P.I.T.A.? Yes, but much less than the inconvenience of not being able to satisfy the consumers needs for hot water...

Maybe you should start looking into the possibility of this "device" in your area.

Get used to the future. IT's here today!

Another point for you plumbers. Remember the water based flux fiasco? It's not over. The EPA is threatening to withold funding for water and sewage treatment plants to states who are not enforcing the water based flux requirement.

Get ready to learn how to solder all over again...:-)

ME

Alan(CaliforniaRadiant)Forbes

We are in

IAPMO country; they are the ones who write the Uniform Plumbing Code which specifically prohibits the use of single wall heat exchangers (HX). I've grown tired of dealing with inspectors; after all, they are just trying to do their job.

Here's what we do to make the inspector feel OK about a single wall HX installation:

1) Buy a flat-plate, double-wall HX.

2) You have to have a hot water circulating loop on the domestic system and before it returns into the indirect, take it through one side of the HX.

3) Take your boiler loop through the other side of the HX and voila, you have a very inefficient way to heat water.

By the way, the single wall HX in the indirect is sitting idle, not connected to anything. After final inspection, disconnect the double-wall HX and connect your indirect.

Please don't scold me for being devious or reprimand me for passing on illicit information that could get others in trouble. This was a method devised by one of my indirect salesmen.

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Earthfire

backflow

Are they requiring Backflow protection at the meter or just demanding double wall HX?

Mark Eatherton1

Just double wall HX'ers...

It is illegal to install a RPZ type backflow preventer in a pit below grade. (at least under the UPC...)

A few of the municipalities here along the front range have started requiring RPZs on the boiler make up. That requires a 3" floor drain, and an annual reinspection/certification.

Denver only require RPZ's on commercial hydronic installations.

ME

Mark Eatherton1

Some times...

a mans got to do what a mans got to do...

Maybe, some day, an organization like the RPA will get enough respect that they can convince the code authoraties that we as contractors know just a little more than the code enforcement officials do, and that we have a better solution to their potential problems.

They're going to have to do a lot more in the area of approving the use of potable water in spacce heating systems in my minds eye before they gain the respect that they will need.

JMHO

ME

J.C.A._3

Yet another,

Use for the "Pro Press". No flux, but to follow the directions as posted, all pipe should be reamed to reduce the effects of "water movement related pipe failures". (I believe it's called hydrolysis?)Chris