Continuous Circulator

Drew_6

I am trying to get the most efficiency from my hot water boiler and have read many of your threads about efficiency. I have an older gas fired boiler with outdoor reset and an automatic damper. Originally, the circulator was connected to the thermostat, but after reading your threads, I changed it to run continuously - with the boiler connected to the thermostat instead. My question is - will the circulator be OK running all the time (during the heating season)? I have a Bell & Gossett circulator 1/6 HP with a continuous rating 40 degrees C. It is fairly old, but I have kept it well maintained and it runs well. Can it run continuously? Thanks for all your great advice!!

Andy G

My circulator has been running constantly since 2000

There is no problem running the B&G circulator in this manner. However, you must oil the motor using the proper oil for small motors at the three oil points every few months. If you are unsure of the oil points go to the B&G website and lookup your model. Another potential maintenance item is the coupling which links the motor to the impellor. This will eventually give out and need replacing. It costs $10-20.

Brad White_9

Better go catch it....

Sure, you can run your circulator 24/7/365.... but how lazy are you?

Personally, yes, I have been known to allow that, a Grundfos 3-speed on low drawing 45 Watts. Later I installed a Ranco controller set to run the circulator based on outdoor temperature. 65 degrees and under, it runs. Done. Will it pay for itself? Sure, in about two years. 45 Watts over half a year (4,380 hours) is 197 kWH per year wasted. At 12 cents (take your local rate) that is $23.65 per year. The Ranco cost me about $45....

The only downside is that many control manufacturers recommend an exercise program where the circulator runs a few minutes every week or so to prevent seizing. This you can do manually.

Mike T., Swampeast MO

Ran my B&G 100 nearly continually for about 4 years. No problems. Did however use a warm-weather shutdown control to stop both the circulator and boiler--and yes, it paid for itself rapidly.

New boiler (Vitodens) also runs its circulator continuously. Smooth and silent as can be... By the way--the Vitodens automatically "exercises" the circulator for a minute or two each day when it's in standby mode. For this reason you should leave it "on" but in "standby" even if you're not using it for DHW.

Ken_40

The only problem...

Might be if the water temp inside a boiler that is NOT designed to run at 140 or less a lot, may condense and rust to death.

Other than that, it is THE most effective way to run your system with minimal fuel use being the sole objective.