Acid washing when required is $500.

I know very little about legal precedent but I'd expect the major meter manufactures (selling into the utility space) to be well incentived to challenge these items best they can, and they have money.Here are the issues, and the reasons that the difference between an air forced system and a boiler/hydronic system are not meaningful for this discussion (ie efficacy issues of sub metering exist for either when method of measurement is measuring heat at point of delivery):In either case, the blower (or pump for a boiler) is the method of 'moving' either air (central air) or water/glycol or equivalent (boiler etc). 

PLUMBING FIXTURESThe bathrooms, toilets and kitchen plumbing fixtures shall only be used for the purpose for which theywere designed or built; sweepings. rubbish bags. acids. sanitary napkins, baby wipes, paper towels.should all be disposed of in regular waste receptacles.

Copper lines usually go bad from acidic water which lets the copper develop pinholes; occasionally you'll have solder joint failure.

Plumbing is a great example - as an ex-plumber I'd take PEX over galvanized any day, and even over copper (at least the newer stuff) especially if you live where the water is somewhat acidic.

It also depends to some degree on your water supply - how acidic it is - and climate,  etc.   

If the copper makes you feel better then use it, plumbers in my area pipe their own houses in pex and only care for copper because they make more on material upcharge and labor to install.As a side note- acidic water breaks down copper, which ingesting can cause health issues, and can cause pinholes in copper piping.

I’ve tried eating 1x a day for 1 year (Not healthy for me) and various water fasting protocols to eventually settling on my current lifestyle of: 1)Taking stairs daily 2)Intermittent fasting of 16 hours daily/ 3-4 Day water fasts Quarterly3)Mineral consumption daily using Fulvic Acid, Icelandic Kelp, a powdered Electrolyte to regular water, Spring Water (Minerals are ESSENTIAL to hydration) 4)Daily Fruit consumption 5)Grass Fed, Grass finished Beef 6)Minimal Fried foods (I still LOVE French fries) 7)No seed oils (only Tallow, butter and/or avocado oil) 8)Cut back on white flour and grains (Minimal breads, pastry, pasta) 9)No soda 10)No dairy (Cow’s milk is for baby calfs)11)Minimal alcohol (Maybe Vodka or Tequila RARELY) 12)At lease 7 hours of sleep daily13)No watching CNN, MSNBC, NY TImes, Washington Post, NPR or ABC, NBC, CBS…………….

Here we go.There are three ways to work on pet urine dark spots on a wood floor after you sand it, wood bleach kits, oxalic acid, and peroxide.

I've seen some do an acid wash and not try to cover up the existing but just clean it up.In the photo, the real wall paint color is by Sherwin Williams Interactive Cream.