Proving boiler safety (UL 2523)

[macattack_ga]

I picked up an older indoor boiler for a song and would like to install it.

Going through the reams of codes and requirements I've discovered that in my jurisdiction a boiler needs to be UL 2523 listed.

Since this boiler was manufacture prior to the drafting of UL 2523.... guess what... it's not listed.

After contacting the "Office of Code Administration" about the issue I've been advised that a request for modification would require that "an equivalent level of safety can be demonstrated, (in this case perhaps by a listing in accordance with another standard, which might be a non-US standard".

GREAT... what does that mean?
I've back and forth with the code folks to identify specific requirements to meet with ZERO success except the boiler must meet UL 2523 requirements. I've ask for those requirements and they don't even know what they are.

I've proposed 18" clearances, thermostatic mixing valve to maintain boiler temps, 600gal storage to minimize idling, low water cut off, auto fill valve, backflow prevention, expansion tank, mixing valve for DHW, pressure release valve, etc... no luck.

I figure I could quit, buy a new boiler or keep barking up this tree... and barking is kinda fun.

Any suggestions for other ideas or approaches?

 

[stee6043]

For what it's worth you are likely installing a "hydronic heating appliance" and not a boiler. In cases such as this the definition is very important even though everyone calls these things boilers.

I'm going to assume you'll be 100% unsuccessful in getting an old boiler to pass these requirements. It sounds like it's heavily focused on the controls (electronics) of the appliance. UL doesn't do house calls and the expense to have a third party lab review your current controller for compliance (with a 99% chance they will confirm non-compliance) would vastly exceed the value of a new boiler, delivered and stocked with 10 cord of seasoned hardwood.

Of course I have NOT read the entire UL document so this is all just a guess. Your mileage may vary...

 

[S.Whiplash]

Yep, stee6043 is right, cost prohibitive. If they're insisting on UL 2523 you're SOL unless you need a new boat anchor. Did you ask the seller why he was selling so cheap?

 

[macattack_ga]

Thanks stee6043: The language for the code with water heaters is a little different.

"Solid fuel-fired boilers shall be listed and labeled in accordance with UL 2523"
"Solid-fuel-fired water heaters shall comply with UL 2523".

S.Whiplash: Previous owner got an OWB.

Probably SOL... but an going to try and identify what is required to "comply".

 

[stee6043]

For what it's worth UL 2523 covers a bunch of items including both hydronic heating appliances and water heaters. They are not the same thing and you are an owner of a hydronic heating appliance, not a water heater. A water heater heats water that is withdrawn for external use. A hydronic heating appliance circulates water between load and heating source and is not withdrawn for external use.

Good luck....

 

[macattack_ga]

stee6043: Super points.

Got the below from a state official (for water heaters... water withdrawn for external use)

"Bottom line is the device needs to be able to control the pressures and temperatures."

<break>

He also provided some useful links from which I've dug up the following:

for HWH
(broken link removed)

From the code....

BOILER. A self-contained appliance from which hot water is circulated
for heating purposes and then returned to the boiler, and which operates at water
pressures not exceeding 160 pounds per square inch gage (psig) (1102 kPa gauge)
and at water temperatures not exceeding 250F (176C).

WATER HEATER. Any heating appliance or equipment that heats
potable water and supplies such water to the potable hot water distribution system.

for Boilers
(broken link removed)

from boiler code:
A hydronic heating appliance is defined as an appliance that maintains a constant atmospheric internal working pressure (nonpressurized vessel) and is designed to heat a liquid, such as water, that is circulated between a heating load and the heating source (appliance).



If it was just a matter of controling the pressures and temperatures there might be a case... but that was not called out in the UL "Information for Boiler Assemblies".

 

[macattack_ga]

Turns out my boiler was asme certified with an "H" stamp and the local code guy is going to accept that in lieu of UL2523.

 

[maple1]

The only thing we need to worry about where I live is what the insurance guy says. There is no 'code official' or whatever input/permitting at all. They only get involved when a building permit is in play, which you don't need for a heating system change.