Bell&Gosset circulating pump

[fish stalker]

I have hot water heat in my house that is circulated by a bell&gosset 100 series pump. the problem that I have is that lately the pump acts up. it comes on for about 5 seconds then is off for about a minute, and this same cycle continues until the house is warm enough for it not to call for any more heat.

Any ideas on what may cause this?

[fishermn]

I am thinking that this unit may have an auto resetting thermal protector that is tripping the motor out. Then the motor restarts when the thermal protector resets.

The problem could also be in the control circuit for the motor. To find out, you would need to check if voltage is being applied to the motor during the minute when it is not running. If voltage is present, the problem is in the motor or pump.

Do you know if this unit has been oiled in the recent past?