Came across this installation in a high end custom home at the one year inspection. Wanted to get some thoughts and then I will post what I said in report.
The room that the units are installed in was originally going to be part of the attic space. According to the homeowners, the decision to finish this room was made at the very end of the build. They are using the room as a treadmill room with children play things present. Based on meeting the parents, I doubt that the kids use this room alone, but are present here when a parent is exercising.
My first concern was that the gas units are located in a unconfined room that is part of the home ventilation and is not separately ventilated. Checked the books and they seem to indicate that this is allowable except in bedrooms and bathrooms. However, I have never run into this in a newer home around here and do not particularly like it. Recommended that they install carbon monoxide detectors in here and consider either isolating the water heaters or changing the room to more of a storage room.
The TPR valves are plumbed straight down to the drain pans. I reported this as not allowed and dangerous to the residents in the event that the valves ever activated while people were in the room.
The pans, there are two typical low end pans, are plumbed together, but if you look closely you will notice that they are not plumbed out of the home. I reported this as wrong.
In lieu of properly plumbing the pans out, as best I can figure, they have installed the WAGS safety solenoid valves in the pans. Theoretically these valves would sense water in the pans and turn off the supply. I also did not like that they only ran the inlet plumbing for the right unit through the solenoid safety valve. The left unit, the second in series, solenoid valve is only connected to the gas control of the left unit. Therefore, the system is depending on the right unit solenoid for cutting off water. I feel that they should properly connect both solenoids to inlet lines for the best level of protection. Could it be argued that the installation of these solenoids valves can take the place of plumbing the pans to the exterior from this location inside the home?
I suspect that the plumber forgot to plumb the TPRs and the pans to the exterior and that they installed the solenoid valves as a way to fix it. The home has had a number of plumbing issues, including leaks and mold remediation already, so the quality of the plumbing work was already in question.
Opinions? Anything I missed? Codes that would not allow these units in this areas, rather than it just being unusual and not a good idea?