Do You Need to Follow the Manufacturer’s Installation Instructions to the Letter?

You need to separate what should, must and shall be done as they relate to a manufacturer’s installation instructions. For those of us who actually read manufacturer’s installation instructions for fun, it’s important that we have a legal mind and understand the difference.

As an example, the installation guide for Rheem (the manufacturer under discussion) says early in the guide that a combination of factors must be used to install the water heater: manufacturer instructions, local codes, utility company requirements, and the Fuel Gas Code.

Some home inspectors wrongly believe that the manufacturer installation instructions always carry the most weight, but if you think about it logically, that can’t be true. Here’s why:

In order to make money — and what company is in business NOT to make money — companies have to manufacture to the lowest common denominator because that’s how they will sell the greatest number of whatever it is they are selling. If they manufactured to the most restrictive code, the cost would be so prohibitive that they wouldn’t sell anything except in the state with the most restrictive code.

Additionally, there simply is no way that a company can know every single city, county, state, and federal code for all 50 states, D.C., Puerto Rico, and the U.S. Virgin Islands. That means that they have to be somewhat general unless there is a federal standard, but even then, federal standards have to be adopted by the company, or city, or county, or state, and quite often they are not.

As an example, there are (federal) standards created by the American National Standards Institute (ANSI) which updates them at various times. If you look at the manufacturer plate on many appliances that were manufactured in America, you’ll find something like this:

Notice that the red arrows point to an ANSI designation and a date. That usually is the relevant manufacturing code and the date of that code. The yellow arrow points to the date of manufacture. Notice that there is a two-year difference between the ANSI date and the date of manufacture.

Russel has found as much as a 10-year difference, even though codes are generally updated every three years. All that means is that the company decided not to pay for the new codes and is still manufacturing to older codes. Good or bad? Just depends.

When it comes to those dastardly words should, shall, and must, shall and must mean that there is no question that the requirement is to be done. It shall be done. It must be done. Should is an entirely different animal. It would be a good idea but doesn’t have to be done.

In the case of the sediment trap, here’s what one looks like:

Notwithstanding the fact that the one in that picture has been installed incorrectly (that’s another blog post), that is only the second one that I have ever found in San Diego during 17 years and thousands of inspections. Why? Because the local codes and utility company requirements (see Figure 1) don’t require them here.

Following is the section from the Rheem installation guide concerning the sediment trap. Russel has boxed it an underlined should, shall, and must relating to other items so you can see how the manufacturer uses these terms. It is not done by accident; it’s done by liability attorneys interested in consumer safety, and, as a result, lack of lawsuits.

Russel has heard, but has not investigated, that gas east of the Mississippi River is dirty while gas west of the Mississippi River is clean. So those of you east of the River will see them while those of us west of the River may or may not, depending on local codes and utility company requirements. The sediment trap in Figure 3 was probably installed by a plumber who moved here from east of the Mississippi River.

Since the manufacturer instructions say that a sediment trap should be used, that means that it doesn’t have to be. To find out, then, if one is required, one has to go to the local codes and utility company requirements. A simple call to the city or county building or code inspector and the local utility company will satisfy that. If they both say it’s not required, then it’s probably not something that should be noted in a home inspection report, in my opinion, of course.

One could spend 90% of the home inspection report telling about how things should be, but that doesn’t mean that they shall or must.