Tank-less water heater PT valve.

[Jeffrey L. Mathis]

Inspected a 140,000 Btu Noritz unit. 6 years old. No PT valve. My opinion is that it needs one. Any comments?
JLMathis

[Jim Luttrall]

I can't say for sure if it "needs" one from a physics and safety point of view... but it needs one from a code and all manufacturers instructions I have perused.

[JB Thompson]

There is a brand of tankless, Titan is model name, that doesn't have a place for a relief valve. I've not been writing this up but have certainly wondered about it.

[Garry Sorrells]

Look at page 19 item 10 in manual http://www.noritz.com/commercial/files/manuals/Installation_Manual-_NCC199-SV.pdf :

In general if anything generates hot water or steam it needs a press relief valve.

[Corn Walker]

Typically a valve such as the Webstone 54443WPR (http://www.webstonevalves.com/default.aspx?page=item+detail&itemcode=54443WPR) is used, which has a location for the TPR valve.