Too hot to handle- Hot water circulation pumps

Too hot to handle- Hot water circulation pumps                  Chelan Real Estate Inspections

Well as always when it comes to home inspection that I see things in streaks. This month’s home inspection streak is about circulation pumps for the hot water systems. These domestic hot water circulation pumps are great in big homes with log runs to get hot water to a fixture in a timely manner versus running water for a minute or two to water. That is just way too much time in our fast paced world and it does waste a good deal of water.

EPA guide on hot water system design-Watersense

So onto the story, I was just talking to a contractor recently and he had an incident with a circulation pump that made me think more about these.

The incident was that he got a call due to a smoke alarm from one of his clients. When he arrived at the home he found it filled with smoke. The culprit was a circulation pump that burned up, literally.

I have used these before on my hydronic radiant heat system. And I have noticed that these pumps run pretty warm… hot, as you would expect when you are running hot water through them, but what is too warm? Well as I did some research I found that most of the manufacturers state that the pumps are good up to 230 degrees which is very hot.

It turns out a major issue with these circulation pumps whether it is for a domestic hot water circulation or hydronics is that they need to be properly sized for the application. This seems to be the number one killer of these pumps.

Most of these hot water recirculation systems are most commonly activated by either a thermostat or a timer. Systems that use a thermostat or timer automatically turn the pump on whenever the water temperature drops below a setpoint, or when the timer reaches a certain setting.

So now to my story… I just performed an inspection on a vacant home that has been winterized. So we get the water restored and I start my plumbing inspection. I get to the water heater and we do not turn it on because of obvious flame roll out on the water heater. But I check the circulation pump and it is hot, very hot, and it is circulating cool water. This I know cannot be right.  

It has been running ever since the water has been turned off. This is not very good for these pumps. Recirculation pumps should be powered off anytime the home’s main water supply is shut off.  Obviously the company that did the winterizing had missed this.

So now I will have these guys on my radar during inspection to see what temperatures they are running at. If they exceed the temperature rating it is time for further evaluation and/or replacement.

“If you think it's expensive to hire a professional to do the job, wait until you hire an amateur.”

Red Adair

NCW Home Inspections, LLC  is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Oroville, Cle Elum, East Wenatchee, Quincy and many more…  

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