Circulation Pump Running Too Much?

[Reicherb]

I have a Well-McLain Series 3 P-D--7 boiler that I believe to be original to the house which was building in 1968. At the end of last winter I discovered that the circulation pump was running constantly. It's entirely possible that it's had been running for the two years that we lived here. I'd been trying to trace down high electrical use for a while.... I traced it down to be a zone valve that kept returning to the open position after I manually turned it off. As the heating season was almost over I simply removed the wire from terminal 2 on the zone valve and put the valve in the closed position until this weekend.

I replaced the valve and then the valve would stay closed until the thermostat called for heat. when it stopped calling for heat, the valve would not close. I traced that down to be an improperly wired thermostat. I corrected the wire and now the valve opens as closes as it should.

Now however, the circulation pump seems to never stop. It's been running about 5 hours now. Before moving the wire on the thermostat, when I manually put the valve in the closed position, the pump would turn off after a few minutes. If I kill the power to the whole system and turn it back on after a minute or two, the pump starts right away. The water temperature is still about 130 degrees (it's warm outside) so I'm thinking maybe this is normal and it will stop when the water cools off. Is that how it should operate? I'm concerned that the pump really should not be running when all 3 of the zone valves are closed as there is actually no where for the water to go...

If it's not operating correctly, any ideas what might be wrong? I've reviewed the valve and the thermostat documentation and believe they are wired correctly.

Thanks,

Brad

 

[Tom Sawyer]

What kind of zone valves

 

[Sponsor]

 

[Reicherb]

They are White-Rodgers 1311-102

The water temp is down near 100 degrees and when I turned the power back on, the pump starting running instantly with no call for heat from any thermostats and all zone valves in the closed position.

Brad

 

[Reicherb]

I turned the boiler back on and sure enough the pump kicked on. The pipes on the main line were still warm though so I briefly cycled the other 2 zone valves on and off and almost immediately the pump turned off.

My gut says that a relay in the boiler controls isn’t sensing that no zone valves are calling for heat and since the water is still warm, it's trying to circulate it. I'm sure one of you boiler geniuses will correct me and explain exactly what is happening though.

Brad

 

[Tom Sawyer]

What kind of zone valves

 

[Reicherb]

They are White-Rodgers 1311-102

 

[Tom Sawyer]

It's either a bad end switch on a zone valve or the circulator relay is stuck closed. If you remove the thermostat wires dies the pump stop

 

[Reicherb]

Which wire do I remove? From Pin 4 on the Zone valves?
http://www.emersonclimate.com/en-us/Products/Valves/Documents/Cat_06_pg0298.pdf

Thanks,

Brad

 

[Tom Sawyer]

Either 3 or 4

 

[Reicherb]

I adjusted the thermostat attached to the new zone valve to call for heat. Before the valve was full open, I adjusted the thermostat to not call for heat. The zone valve continued past the open position and closed.

The boiler fired and circulation pump started running. The boiler turned off but the circulation pump kept running. I removed the wire from connection 4 on all 3 zone valves and the pump continued to run.

What does this tell you the culprit likely is?

Thanks,

Brad

 

[Tom Sawyer]

The circulator relay

 

[Reicherb]

Forgive my ignorance, but what part is that in image1? A, B, both, something else?

Thanks,

Brad

 

[Tom Sawyer]

Wow, old crap. Ok, so pull one of the wires off of the TT terminals. Doesn't matter which one. Did the pump stop? If it did, the problem is in the zone valve or its wiring. If it didn't that control needs to be changed or its wired wrong.

 

[Reicherb]

T1 and T3 are wired together. When I took the cover off the controls everything stopped. I took the wire off T2 and put the cover back on. The pump did NOT start. I took the cover back off the control and put the wire back on T2. When I put the cover back on, the pump did NOT start like I would expect.

Do you believe this to be a zone valve issue?

Thanks,

Brad

 

[Mass_ tech89]

What is the main control on your burner? You could simply need to adjust your low limit to the correct temp. if you removed t and t from your aqustat relay and the circulator stopped its because you removed the call for heat. The two wires that connect to t t on your control send 24volts to the circulator relay coil. When you remove the wires you remove the 24 V from the circulator relay and you de energize the circulator The problem is with your control can you take a picture of the control most likely it will be just a replacement as you cannot field service unless it just needs adjustment.

 

[Reicherb]

I pried the contacts apart on the relay and it seem to be working correctly now.

Brad