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Should Circulator be on Continously?

This is in a hydronic heating system for a house. The circulator is wired directly to the wall switch which supplies power to the boiler and, as a result, the pump runs constantly throughout the year, even when there is no call for heat.

I see disadvantages to this - electricity consumed by the pump and wear and tear on the pump. Are there any benefits to running the pump constantly?

I am thinking of wiring up the pump so that it only turns on when the thermostat calls for heat.

Re: Should Circulator be on Continously?

This type of circulator wiring setup is usually used for heating season low water temperature radiant systems, both sub-floor radiant PEX tubing and baseboard/radiators, and for those systems that have an outdoor reset (ODR) system.

No need to run the circs in warm months---so check with your service person if you have a service contract with someone.

Some boilers come on periodically in the summer to heat the domestic hot water, but don't need the circ.

However, these circs are usually lubricated by the water they pump & should be run just for a few minutes twice a month in the summer to prevent seize-up of the internal impeller---no need to run a circ that is lubricated by motor oil.

Re: Should Circulator be on Continously?

Thanks, NashuaTech. The pump (Armstrong S25) is oil-lubricated, so I will wire it up to come on only when the stat is calling for heat. There is no underfloor radiant heat, just typical cast iron hot water rads.

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