All for the want of a 6202Z bearing.
Halfords? Quick Fit? I think most of McDonalds staff could have sorted this one
For anyone wanting to know how to replace the whining bearings on one of these boilers, i hope you find this thread:
To detremine what exactly is at fault and making the noise I reconnected the motor after splitting from the fuel pump, it whined like a banshee. this might be unsafe advice, but i reckoned that since there was no drive to the pump, it was relatively safe?
I am sure someone will advise if this is not good practice.
Disconnect the unit from the mains supply
Remove the upper burner cover by taking off the 2 wing nuts:
Disconnect the quick disconnect electrical couplings going to the motor and to the sensor
Remove the 2 pinch screws at the front, about 7 and 5 o'clock position
Lift the complete burner unit up out of it's housing
Rotate to get access to the large philips head screws that retain the motor and fan unit to the burner body
Remove these screws with a correctly fitting screw driver. I used a wrench on the shaft of mine and tapped the screw head to shock loose before applying torque.
At this point the motor and fan unit will lift clear of the burner unit. Be carefull with the drive coupling that transfers drive from the fan through to the fuel pump, this comes away with the fan.
This coupling is plastic and can be pulled off the end of the shaft. it tends to be a bit sticky because of the dried up crud that has got in there over the years. Do not try to twist or prise off, it pulls straight off. it is plastic and quite delicate.
Next, there is a clue on the outside of the fan blades, you will see a hole where a 4mm allen key passes to undo the grub screw, this releases easily and the fan unit then pulls straight off the end of the spindle.
So with the fan removed you can turn to dismatling the motor.
remove the 14mm nut retaining the earth.
Remove the 4 screws that hold the assembly together and the assembly easily splits. The 6202Z bearings back and front are easily removed with a standard bearing puller, or other device if not available.
£3 later and you are back in business, actually £6, I took the plunge and replaced the back bearing while I was in there.
Now, I have built my own Manx Grand Prix winning race engines so am reasonable competent mechanically, but there isn't anything scary about this job. Suggest maybe get the bearings before you start, so there is no down time.
Good luck
Gavin
