I feel it is absurd to say that the use of a vessel that is safe for use as a water heater is somehow unsafe if that same water is used for radiant heating.

His main objections seem to be that the use of the water heaters is unsafe, contrary to existing codes, and at odds with the interests of the “boiler” manufacturers.

Although it may be true that “boilers” have more safety factors than water heaters, that does not make the water heaters unsafe when installed properly and used for radiant heating applications. If anything, using a typical residential water heater for radiant heating in a residence is safer than when used for domestic hot water (DHW) because when water heaters are used for radiant heat, they are typically operated at temperatures well below the temperatures used for domestic hot water. I can’t understand the logic that using a water heater for DHW is safe, yet somehow when it is used at a lower temperature it is unsafe.

I would suspect that the ASME code he refers to is for vessels with greater temperatures and/or pressures than the kind used in residential radiant heat applications. I don’t even know how many states use ASME codes for residential applications.

As far as life expectancy of the heater, I agree with the estimated 7 to 10 years for most water heater applications. However, a closed system would usually extend the life of a water heater, as it would introduce less oxygen and fewer minerals. But this is a poor reason not to use water heaters instead of boilers in this application. Many consumers would prefer an appliance that has an initial cost of around $200 and can be installed correctly by a lot of installers to an appliance costing five to 30 times that and has a much smaller base of qualified installers. No matter how you add it up, over the life of one or even two “boilers,” the water heaters cost far less to own.

Is it contrary to the interests of the boiler manufacturers to use water heaters for heating applications? Yep. But that is not a good reason to prohibit their use, in my opinion.

There is also the fact that radiant heating uses low-temperature water as compared to typical baseboard radiation. Using traditional boilers for radiant heat requires the addition of costly controls and/or hardware to deliver low-temperature water to the radiant heat device and at the same time keep the boiler above condensing temperature. Water heaters are designed to operate at the temperatures used for radiant heat; boilers are not. There are boilers on the market that are designed to condense and thus do not have this concern. However, they have an initial cost of $2,000 to $3000, and in my experience have had higher ownership costs, as they are “high-tech” and many have experienced expensive repairs.

I checked with the Bradford-White Corp. and found that not only does using a residential gas water heater for heating applications not void the warranty, most of their heaters are marked as suitable for use “for heating potable water or heating.” The only restrictions the manufacturer has for heating would be the introduction of chemicals into the system that could render it unsafe for potable water uses. Mr. Peetz’s statement that “any warranty is void when used for a hot water heating application” is just wrong.

It appears to me that another building inspection official is drawing lines in the sand about what is and is not safe, without the benefit of science or practicality. Regulators seem to disregard consumer cost as a factor having any value, yet make unsubstantiated claims that proper use of a proven product in a proven application is “unsafe” and “voids any warranty.” I suspect Mr. Peetz is not familiar with the concerns of low-temperature heating like condensation, or with the temperatures and pressures experienced in a radiant heating system. There is no reason to declare that using a water heater for heating, when proper design and application procedures are followed, is unsafe and voids the manufacturer’s warranty. This application probably is against regulations in Missouri and other states, but that does not in and of itself make it unsafe. If it is improper installations Mr. Peetz is concerned about, an improper installation of a boiler is no safer than an improper installation of a water heater.

Scott Robinson

President

Apple Heating, Inc.

Ashtabula, OH

A/C for the Elderly

Air conditioning is becoming a necessity — especially for elderly citizens. Retirement homes should have properly functioning and maintained air conditioning centrally distributed throughout the facility.

Shawn R. Lynch, Sr. Installation Mgr. CPS Corporation Marlborough, MA

Publication date: 08/20/2001