Thread: Titan water heater

Can someone advise me whether a pressure relief valve and extension are required on these electric tankless water heaters. I have never seen one but I am convinced one should be there.

Thanks Jim

The manual says nothing and the pictures of the mechanicals show nothing that looks like a TPRV. They do have a tool free # on their website.

From the 2012 IRC:
- SECTION P2803 RELIEF VALVES - - P2803.1 Relief valves required.
- - - Appliances and equipment used for heating water or storing hot water shall be protected by:
- - - - 1. A separate pressure-relief valve and a separate temperature-relief valve; or
- - - - 2. A combination pressure- and temperature-relief valve.
- - P2803.2 Rating.
- - - Relief valves shall have a minimum rated capacity for the equipment served and shall conform to ANSI Z21.22.
- - P2803.3 Pressure-relief valves.
- - - Pressure-relief valves shall have a relief rating adequate to meet the pressure conditions for the appliances or equipment protected. In tanks, they shall be installed directly into a tank tapping or in a water line close to the tank. They shall be set to open at not less than 25 psi (172 kPa) above the system pressure but not over 150 psi (1034 kPa). The relief-valve setting shall not exceed the tanks rated working pressure.
- - P2803.4 Temperature-relief valves.
- - - Temperature-relief valves shall have a relief rating compatible with the temperature conditions of the appliances or equipment protected. The valves shall be installed such that the temperature-sensing element monitors the water within the top 6 inches (152 mm) of the tank. The valve shall be set to open at a temperature of not greater than 210°F (99°C).
- - P2803.5 Combination pressure-/temperature-relief valves.
- - - Combination pressure-/temperature-relief valves shall comply with all the requirements for separate pressure- and temperature-relief valves.
- - P2803.6 Installation of relief valves.
- - - A check or shutoff valve shall not be installed in the following locations:
- - - - 1. Between a relief valve and the termination point of the relief valve discharge pipe;
- - - - 2. Between a relief valve and a tank; or
- - - - 3. Between a relief valve and heating appliances or equipment.
- - - P2803.6.1 Requirements for discharge pipe.
- - - - The discharge piping serving a pressure-relief valve, temperature-relief valve or combination valve shall:
- - - - - 1. Not be directly connected to the drainage system.
- - - - - 2. Discharge through an air gap located in the same room as the water heater.
- - - - - 3. Not be smaller than the diameter of the outlet of the valve served and shall discharge full size to the air gap.
- - - - - 4. Serve a single relief device and shall not connect to piping serving any other relief device or equipment.
- - - - - 5. Discharge to the floor, to the pan serving the water heater or storage tank, to a waste receptor or to the outdoors.
- - - - - 6. Discharge in a manner that does not cause personal injury or structural damage.
- - - - - 7. Discharge to a termination point that is readily observable by the building occupants.
- - - - - 8. Not be trapped.
- - - - - 9. Be installed to flow by gravity.
- - - - - 10. Not terminate more than 6 inches (152 mm) above the floor or waste receptor.
- - - - - 11. Not have a threaded connection at the end of the piping.
- - - - - 12. Not have valves or tee fittings.
- - - - - 13. Be constructed of those materials listed in Section P2905.5 or materials tested, rated and approved for such use in accordance with ASME A112.4.1.
- - P2803.7 Vacuum-relief valve.
- - - Bottom fed tank-type water heaters and bottom fed tanks connected to water heaters shall have a vacuum-relief valve installed that complies with ANSI Z21.22.

Note that there is no exception for tankless water heaters as the code states "Appliances and equipment used for heating water or storing hot water shall be protected by ... " and tankless water heaters are used "for heating water".

The above said, the code also states:
- P2801.2 Installation.
- - Water heaters shall be installed in accordance with this chapter and Chapters 20 and 24.


SECTION M2005 WATER HEATERS
- M2005.1 General.
- - Water heaters shall be installed in accordance with the manufacturer’s instructions and the requirements of this code. Water heaters installed in an attic shall comply with the requirements of Section M1305.1.3. Gas-fired water heaters shall comply with the requirements in Chapter 24. Domestic electric water heaters shall comply with UL 174. Oiled-fired water heaters shall comply with UL 732. Thermal solar water heaters shall comply with Chapter 23 and UL 174. Solid-fuel-fired water heaters shall comply with UL 2523.


Note the above states "Water heaters shall be installed in accordance with the manufacturer’s instructions and the requirements of this code"

The code also states that the most restrictive shall apply.

Sooo ...
- Are T&P valves required for tankless water heaters? Probably not.
- Are pressure relief valves required for tankless water heaters? Probably.

If the manufacturer's installation instructions state something like: DO NOT install a temperature and pressure relief valve ... that is more restrictive than the code stating that one is required as a general statement.

Other Ifs ... Ands ... or Buts ... may apply too.

Pressure Relief Valve

All Products » Tankless Installation Accessories Pressure Relief Valve List Price: $37.99 You Save: 13.16%Price: $32.99 Quantity: Email a Friend Ask a Question Price Match Printable Page Download Brochure Download Installation Manual Pressure relief only valve to be used when installing tankless water heaters in CPVC or similar piping material. Adjustable pressure setting, easy installation. Calibrated Pressure Relief Valves are spring operated brass valves designed for use only as protection from the build up of excessive pressure in systems containing water, oil or air. Series 530C valves incorporate a calibrated adjustment feature for setting the valve to the relief pressure required. These valves are ideally suited for bypass thermal expansion relief. Features Calibrated adjustment feature for setting valve to relief pressure required Adjustable range 50 – 175psi (3.4 – 12.1 bar) All brass construction All stainless steel spring Buna-N disc on machined body seat Inlet (bottom), 3/4" male NPT threaded Outlet/Drain (side), 1/2" female NPT threaded Maximum Temperature: 180°F (82°C) Spring Ranges: 1⁄2" or 3⁄4" (15 or 20mm): 50 – 175psi (3.4 – 12.1 bar) 3⁄4" (20mm): 100 – 300psi (6.9 – 20.7 bar) Dimensions: 3"h x 1 5/8" w Weight: 0.37 lbs I found this on the website. This particular installation was copper so I guess it does not require one

Originally Posted by Jerry Peck

From the 2012 IRC:
- SECTION P2803 RELIEF VALVES - - P2803.1 Relief valves required.
- - - Appliances and equipment used for heating water or storing hot water shall be protected by:
- - - - 1. A separate pressure-relief valve and a separate temperature-relief valve; or
- - - - 2. A combination pressure- and temperature-relief valve.
- - P2803.2 Rating.
- - - Relief valves shall have a minimum rated capacity for the equipment served and shall conform to ANSI Z21.22.
- - P2803.3 Pressure-relief valves.
- - - Pressure-relief valves shall have a relief rating adequate to meet the pressure conditions for the appliances or equipment protected. In tanks, they shall be installed directly into a tank tapping or in a water line close to the tank. They shall be set to open at not less than 25 psi (172 kPa) above the system pressure but not over 150 psi (1034 kPa). The relief-valve setting shall not exceed the tanks rated working pressure.
- - P2803.4 Temperature-relief valves.
- - - Temperature-relief valves shall have a relief rating compatible with the temperature conditions of the appliances or equipment protected. The valves shall be installed such that the temperature-sensing element monitors the water within the top 6 inches (152 mm) of the tank. The valve shall be set to open at a temperature of not greater than 210°F (99°C).
- - P2803.5 Combination pressure-/temperature-relief valves.
- - - Combination pressure-/temperature-relief valves shall comply with all the requirements for separate pressure- and temperature-relief valves.
- - P2803.6 Installation of relief valves.
- - - A check or shutoff valve shall not be installed in the following locations:
- - - - 1. Between a relief valve and the termination point of the relief valve discharge pipe;
- - - - 2. Between a relief valve and a tank; or
- - - - 3. Between a relief valve and heating appliances or equipment.
- - - P2803.6.1 Requirements for discharge pipe.
- - - - The discharge piping serving a pressure-relief valve, temperature-relief valve or combination valve shall:
- - - - - 1. Not be directly connected to the drainage system.
- - - - - 2. Discharge through an air gap located in the same room as the water heater.
- - - - - 3. Not be smaller than the diameter of the outlet of the valve served and shall discharge full size to the air gap.
- - - - - 4. Serve a single relief device and shall not connect to piping serving any other relief device or equipment.
- - - - - 5. Discharge to the floor, to the pan serving the water heater or storage tank, to a waste receptor or to the outdoors.
- - - - - 6. Discharge in a manner that does not cause personal injury or structural damage.
- - - - - 7. Discharge to a termination point that is readily observable by the building occupants.
- - - - - 8. Not be trapped.
- - - - - 9. Be installed to flow by gravity.
- - - - - 10. Not terminate more than 6 inches (152 mm) above the floor or waste receptor.
- - - - - 11. Not have a threaded connection at the end of the piping.
- - - - - 12. Not have valves or tee fittings.
- - - - - 13. Be constructed of those materials listed in Section P2905.5 or materials tested, rated and approved for such use in accordance with ASME A112.4.1.
- - P2803.7 Vacuum-relief valve.
- - - Bottom fed tank-type water heaters and bottom fed tanks connected to water heaters shall have a vacuum-relief valve installed that complies with ANSI Z21.22.

Note that there is no exception for tankless water heaters as the code states "Appliances and equipment used for heating water or storing hot water shall be protected by ... " and tankless water heaters are used "for heating water".

The above said, the code also states:
- P2801.2 Installation.
- - Water heaters shall be installed in accordance with this chapter and Chapters 20 and 24.


SECTION M2005 WATER HEATERS
- M2005.1 General.
- - Water heaters shall be installed in accordance with the manufacturer’s instructions and the requirements of this code. Water heaters installed in an attic shall comply with the requirements of Section M1305.1.3. Gas-fired water heaters shall comply with the requirements in Chapter 24. Domestic electric water heaters shall comply with UL 174. Oiled-fired water heaters shall comply with UL 732. Thermal solar water heaters shall comply with Chapter 23 and UL 174. Solid-fuel-fired water heaters shall comply with UL 2523.


Note the above states "Water heaters shall be installed in accordance with the manufacturer’s instructions and the requirements of this code"

The code also states that the most restrictive shall apply.

Sooo ...
- Are T&P valves required for tankless water heaters? Probably not.
- Are pressure relief valves required for tankless water heaters? Probably.

If the manufacturer's installation instructions state something like: DO NOT install a temperature and pressure relief valve ... that is more restrictive than the code stating that one is required as a general statement.

Other Ifs ... Ands ... or Buts ... may apply too.