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Pressure Relief Valves on this Tankless Water Heater?

Manufactures installation instructions are your ticket, code only requires it on tank water heaters or water heaters where it is in the manufacturer's instructions. Many tankless units do require it.
 
This is what the manual says, see below.

Does California require a T&P valve for a tankless water heater?

This automatic tankless water heater is equipped with both computer-controlled and electro-mechanical auto resetting thermostat switches for high-limited temperature protection. Since this product does not use a storage tank, the use of a temperature pressure relief valve (T&P) is not required for most installations. UL Standard 499 does NOT require that a pressure relief valve be used. However, a T&P valve may be required to meet installation codes in your area. If one is required, install the pressure relief valve in accordance with local codes and ensure that it operates correctly and that air is purged from the valve prior to installing the water heater. When connecting to Flex or High Temperature CPVC pipe, we recommend that a T&P valve be used for added safety. Please note: Installations in the Commonwealth of Massachusetts and State of Kentucky require a pressure relief valve. Please check your local installation codes for any special requirements.
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It comes down to the capacity of the internal coil. If the coil has a capacity of a certain volume, the heater is classified as a storage water heater. The same holds true with swimming pool water heaters. A problem that you might encounter is finding a T&P valve that handles the BTU rating of the heater.
 
When connecting to Flex or High Temperature CPVC pipe, we recommend that a T&P valve be used for added safety.

What piping is used in your plumbing supply lines?
 
mark handler said:
As per the CPC, only when required by the Manufacturer
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I disagree with that. The reference to the manufacturer is related to the T&P device.

504.4 Pressure-Limiting Devices.
A water heater installation shall be provided with over pressure protection by means of an approved, listed device installed in accordance with the terms of its listing and the manufacturer’s installation instructions.

504.5 Temperature-Limiting Devices.
A water heater installation or a hot water storage vessel installation shall be provided with over temperature protection by means of an approved, listed device installed in accordance with the terms of its listing and the manufacturer’s installation instructions.
 
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ICE said:
I disagree with that. The reference to the manufacturer is related to the T&P device.

504.4 Pressure-Limiting Devices.
A water heater installation shall be provided with over pressure protection by means of an approved, listed device installed in accordance with the terms of its listing and the manufacturer’s installation instructions.

504.5 Temperature-Limiting Devices.
A water heater installation or a hot water storage vessel installation shall be provided with over temperature protection by means of an approved, listed device installed in accordance with the terms of its listing and the manufacturer’s installation instructions.
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Don't understand your post....you are disagreeing with my post? I posted the CPC, CA Plumbing Code, in the post. Do you disagree with the Code?
 
mark handler said:
Don't understand your post....you are disagreeing with my post? I posted the CPC, CA Plumbing Code, in the post.
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CPC 504.4 and 504.5 say that temperature limiting and pressure limiting devices are required for all water heaters. Seems straightforward enough. And that is in contradiction with your earlier post:

mark handler said:
As per the CPC, only when required by the Manufacturer
Click to expand...

Cheers, Wayne
 
wwhitney said:
CPC 504.4 and 504.5 say that temperature limiting and pressure limiting devices are required for all water heaters. Seems straightforward enough. And that is in contradiction with your earlier post:



Cheers, Wayne
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Both pressure and temperature limiting devices, "...accordance with the terms of its listing..." per code sections cited above
 
mark handler said:
Both pressure and temperature limiting devices, "...accordance with the terms of its listing..." per code sections cited above
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In 504.4 and 504.5, "its listing" refers to the listing of the temperature or pressure limiting device, not the listing of the water heater. 504.4 always requires a pressure limiting device for a water heater, and 504.5 always requires a temperature limiting device for a water heater.

Cheers, Wayne
 
wwhitney said:
In 504.4 and 504.5, "its listing" refers to the listing of the temperature or pressure limiting device, not the listing of the water heater. 504.4 always requires a pressure limiting device for a water heater, and 504.5 always requires a temperature limiting device for a water heater.

Cheers, Wayne
Click to expand...
504.4 is for TANKED (Storage) water heaters, NOT Tankless
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mark handler said:
504.4 is for TANKED (Storage) water heaters,
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You quoted the wrong code. That's the IPC, but we were discussing the CPC, the California Plumbing Code, based on the UPC. The CPC has no such limit, as you can plainly see from the CPC quotes earlier in the thread.

Cheers, Wayne
 
No it is the 2018 UPC code. If CA amended that section then please post it.
No post referenceing expansion tanks and the requirements for T & P valve requirements and non-storage instantaneous heaters.
 
The CA plumbing code has the same requirements that I posted regarding a T&P requirement when a expansion tank is required or installed in a water system.
Every meter our city PW issues has a double check backflow installed on them, Therefore, every system is required to install an expansion tank is required to install a T&P valve
"except for listed non-storage instantaneous heaters having an inside diameter of not more than 3 inches (80mm)"
Second column 1st paragraph.
It is another section that may apply to the OP's question that may have been overlooked by the installer and inspector.
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