Oil Boiler problem....

[ooglewoogle]

We have an older Bentone oil boiler. It has recently developed an issue on cold start whereby it is quite loud with a squirrely squealing type noise. This subsides after about 5 - 10 minutes of use and settles down to quiet.

I will take off the motor tomorrow and check the bearings, but I think they are good as I changed them not long ago...and this seems a different, less constant noise. I did notice tonight when looking for the source that the fan motor is 'extremely' hot in operation....is this usual in these? Or could this point to the fuel pump bearing getting stiffer to turn/on the way out?

At first the noise wouldn't be present on pre-ignition....then would get loud when the solenoid opened, which makes me suspect the Danfoss fuel pump. Now, from a cold start the noise is there even during pre-ignition.

Many thanks for any help.

 

[Burnerman]

I’d go for bearings again at this early stage, but also check the pump to motor coupling and check for any kero leaks at the pump spindle.
John

 

[oilhead]

Do you have a Bentone burner with an oil pump that piggy backs the motor, or is it driven by a coupling through the burner?
If the former, remove the oil pump and see if the noise goes. At the same time check for stiffness/rough spots on the oil pump, and leakage from the pump shaft. If the latter, again remove the pump as above, but also check the drive dogs and shaft on the coupling.
Forget bearing changes and put a new motor on if that is what has failed.

 

[ooglewoogle]

I’d go for bearings again at this early stage, but also check the pump to motor coupling and check for any kero leaks at the pump spindle.
John

You were dead on Burnerman....motor bearings it was again! I worked some fresh grease into them to keep us going until the new ones arrive....and we are back running as sweet as a nut. I was sure it wasn't the motor bearings again as the noises were very uncharacteristic....but there you go.

Forget bearing changes and put a new motor on if that is what has failed.

Is there a reason to replace the motor rather than just the bearings? Planning a new system soon, so it's just to get us by for now.

Thanks both for replies, it's much appreciated.
Slàinte.

 

[Burnerman]

Personally I don’t think there’s any need to replace the motor just for bearing wear.....I use the 6202zz bearings (good make specified) and I think they are better than the rubber sealed ones.
Mind you, when you open them up it’s surprising just how little grease there’s in there.
John

 

[BoilerBob]

You can burn out bearings by over greasing them. Bob

 

[oilhead]

Why do your bearings keep wearing out?

 

[Burnerman]

Nasty chinese bearings, no doubt!
John

 

[BoilerBob]

I still have a box of very old but new SKF bearings zz type fit and forget when they’ve gone the motor is done. Bob