I wanted to have a tankless installed under my bar, but the plumber that was going to do the work says that it will be very expensive to do since it requires extra copper pipe to install a T&P valve. Apparently the code for the city he works in requires it. The manufacturer does NOT require one....because its not needed. I had no idea the code applied to separate cities.
Is this right or are they just being lazy?
It is not at all unusual for cities, towns, states to have their own amendments to one of the national code sets. Now, whether the plumber is correct or not, I cannot tell you - you'd have to check with the local permitting/inspector's office or find it online.
For example, in MA, any plumbing fixture has to have been tested and approved before it can legally be installed. They have their own website where you can check. There is an appeal process from what I understand. Funny thing is you can buy stuff not on the list, but it is technically illegal to install it.
Important note - I'm not a pro
Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013