CIRCULATOR PUMP BURN OUT

[TJCURRO]

I have residential a crown boiler with an indirect fired water heater. The circulator pump is a Bell & Gossett
NRF-22. The problem is that it continues to burn out every 3 or 4 months. I am beginning to believe that it may be too close to the boiler and the heat is too great. Does anyone know how far this pump should be located from the boiler? its currently about 24inches away.

 

[ewdudley]

Hi, welcome to the forum.

If the boiler is insulated much at all then the proximity of the pump to the boiler shouldn't make too much difference in ambient temperature.

According to B&G these are the things to look out for:

• The pumps shall be horizontal.
• Pumps to be suitable for 240°F.
• Motors shall be non-overloading at any point on the pump curve.
• Minimum size of 14 AWG copper electrical wire.

Presumably the water is well below 240°F, but is it?

Is the pump horizontal?

What is the diameter and total length of the pipe loop that the pump is driving?

What is the height of the system? What is the operating pressure range? Where is the expansion tank connected?

What is the gauge and total length of the wire feeding the pump? Is there a possibility of a poor electrical connection in the circuit feeding the pump?

 

[Bob Rohr]

Hi, welcome to the forum.

If the boiler is insulated much at all then the proximity of the pump to the boiler shouldn't make too much difference in ambient temperature.

According to B&G these are the things to look out for:

• The pumps shall be horizontal.
• Pumps to be suitable for 240°F.
• Motors shall be non-overloading at any point on the pump curve.
• Minimum size of 14 AWG copper electrical wire.

Presumably the water is well below 240°F, but is it?

Is the pump horizontal?

What is the diameter and total length of the pipe loop that the pump is driving?

What is the height of the system? What is the operating pressure range? Where is the expansion tank connected?

What is the gauge and total length of the wire feeding the pump? Is there a possibility of a poor electrical connection in the circuit feeding the pump?

I have residential a crown boiler with an indirect fired water heater. The circulator pump is a Bell & Gossett
NRF-22. The problem is that it continues to burn out every 3 or 4 months. I am beginning to believe that it may be too close to the boiler and the heat is too great. Does anyone know how far this pump should be located from the boiler? its currently about 24inches away.

Got any pictures? Commonly pumps fail in short periods like that because they are deadheaded. Basically the pump continues to run with a valve closed somewhere in the system.

Another cause is excessive air in the circuit, that is a wet rotor circ and needs fluid to keep the bearings happy and healthy.

Voltage correct and stable?

 

[davem3261]

I also have a crown oil boiler. Please take a picture of how the circulator is mounted.

 

[TJCURRO]

Got any pictures? Commonly pumps fail in short periods like that because they are deadheaded. Basically the pump continues to run with a valve closed somewhere in the system.

Another cause is excessive air in the circuit, that is a wet rotor circ and needs fluid to keep the bearings happy and healthy.

Voltage correct and stable?

I tried draining some of the boiler water to maybe release trapped air. This seemed to be the problem since the grinding noise has ceased since then.
Lets hope that this is the solution, since it appears to have been mounted correctly, electrical is stable, etc. Thanks for the advise.

 

[TJCURRO]

I also have a crown oil boiler. Please take a picture of how the circulator is mounted.

I think I solved the problem by bleeding the air from the boiler.

 

[Bob Rohr]

I think I solved the problem by bleeding the air from the boiler.

Check the flow direction. If the pump has been replaced it may have been installed pumping the wrong direction? The check valve below will have a direction arrow, as will the pump body.