Grundfos Circulator Pumps Constantly Runs

[pikachu1234]

Hi,

I'm a new homeowner and I'm trying to troubleshoot an issue with the circulator pump. Recently, the circulator pump to the hot water heater is constantly running when it wasn't the case before. The circulator pump is controlled by a 4 zone Taco control valve system. The hot water is zone 4 and the light has been on for a few days at least when it was never the case. The pump is triggered by an aquastat on the hot water heater. I'm not sure what the setting for the aquastat should be but I have it at 160 and the differential is at around 7 degrees. The High temperature on the furnace setting is 171. From what I understand, if the water temperature in the hot water heater is above 160 then the circulator pump won't run?

Any advice is appreciated!

 

[Bannerman]

Your 'furnace' is called a boiler. The Water Heater is an indirect type as there will be a heat exchanger within the water storage tank that permits hot water produced in the boiler to transfer heat to the cooler water in the storage tank without mixing.

160F in the hot water storage tank seems excessive. To prevent scalding, most water heaters will supply hot water that is maximum 120F.

When you reduce the temperature setting on the aquastat to a lower number such as 120F, does the pump then shut off?

 

[Sponsor]

 

[pikachu1234]

Your 'furnace' is called a boiler. The Water Heater is an indirect type as there will be a heat exchanger within the water storage tank that permits hot water produced in the boiler to transfer heat to the cooler water in the storage tank without mixing.

160F in the hot water storage tank seems excessive. To prevent scalding, most water heaters will supply hot water that is maximum 120F.

When you reduce the temperature setting on the aquastat to a lower number such as 120F, does the pump then shut off?

Yes it does actually. I think the aquastat was loose, like it wasn't all the way in the heater so I think that fixed it. Thank you.

 

[pikachu1234]

Your 'furnace' is called a boiler. The Water Heater is an indirect type as there will be a heat exchanger within the water storage tank that permits hot water produced in the boiler to transfer heat to the cooler water in the storage tank without mixing.

160F in the hot water storage tank seems excessive. To prevent scalding, most water heaters will supply hot water that is maximum 120F.

When you reduce the temperature setting on the aquastat to a lower number such as 120F, does the pump then shut off?

Is there a recommended setting for the differntial on the aquastat? I have it set to 20 degrees.