Shunt Trip for controls circuit on Natural Gas Water Heater

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Shujinko

Shujinko

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Is a Shunt Trip for the controls circuit on a Natural Gas Water Heater required by code? If so, which code requires this? I can't find it anywhere. This is for a business type occupancy.

Thanks.
 
Shujinko said:
Is a Shunt Trip for the controls circuit on a Natural Gas Water Heater required by code? If so, which code requires this? I can't find it anywhere. This is for a business type occupancy.

Thanks.
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Is this in relation to a fire alarm panel?
 
Shujinko said:
No, unless the fire alarm code requires a shunt trip for a natural gas water heater.
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No, the FACP isn't required to touch the gas water heater that I've ever seen.

More generally, I've never seen a shunt trip for a natural gas water heater. Why would anyone want to remove electricity to the water heater? More importantly, how would you trip the shunt? What kind of signal would you use? The danger in malfunction is gas going where it shouldn't, not electricity going where it shouldn't. A really simple standing pilot heater doesn't have any electric that I know of.
 
Larger gas water heaters have controls to open the flue damper & open the gas valve & light the burners, simplified version of what goes on, but remove 120V power & it shuts down.
 
norcal said:
Larger gas water heaters have controls to open the flue damper & open the gas valve & light the burners, simplified version of what goes on, but remove 120V power & it shuts down.
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Yes, but the OP's question was specifically about shunt trip. What would provide the signal for a shunt trip? And why use a shunt trip, why not use a relay to open the circuit, one with manual reset if you really need it?
 
Shujinko said:
Is a Shunt Trip for the controls circuit on a Natural Gas Water Heater required by code? If so, which code requires this? I can't find it anywhere. This is for a business type occupancy.

Thanks.
Click to expand...
Don't confuse required E-stops needed on boiler systems with domestic water heaters. The rating of the boiler vessel is what kicks that requirement in. Domestic water heaters don't operate as as high of a temp or pressure. Shunt trip isn't a requirement on those either but is one possible method, you just need a method of removing power to burner controls from specified location(s).
 
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