Burner Motor Bearings noisy Heatslave 20/25

[salixarbour]

Hi chaps.

I’d like to change the bearings in the burner motor of my Worcester Heatslave 20/25, and I’m just looking for a few helpful hints. I’m okay with changing the actual motor bearings (6202 ZZ’s) as the engineers at work have offered to pull and press the replacements.
I think the job of removing the motor should be well within my capability, albeit as it’s my first time doing this job, I do need to check a few things out.

My questions:
Should I remove the whole of the burner unit (B11) completely, for ease of access, and if so, how?
I can see just two small screws over the top of the blast tube, at positions 11 and 1 o’clock. These appear to be the only screws retaining the whole of the burner unit (with motor, pump and control box etc).

Hopefully the following plan is correct.
Before starting to remove the burner unit, I intend to :
Switch off the power (good idea).
Turn the oil isolation valve to off (situated just to the rear of the my 20/25).
Disconnect relevant electrical connectors.
Remove the oil feed pipe where it connects to the Danfoss pump.
Undo the two grub screws which hold the Danfoss pump in place, and slide the pump away
from the rear of the motor.
Then finally undo the two screws above the blast tube (mentioned above), and
remove the burner unit with motor still attached.

Am I on the right track, chaps? Any advice would be much appreciated.

The unit is professionally maintained and serviced, and had a new Danfoss oil pump fitted and full service just last month. However, it seems increasingly difficult these days to contact and schedule a visit from a good engineer. I had to wait nearly a month for that leaking Danfoss pump to be replaced! Also of course, if I can do this job myself, then there’s money to be saved, as well as job satisfaction.

I’ve read through all the previous posts on this job within this forum, and those have been really helpful. I’ve also tried to find anything similar on YouTube.

I’d best stop writing. Again, any advice would be very much appreciated.

Alan. Cheshire. UK.

 

[Best]

Hi Alan and Welcome to the forum!
The old leaking oil pump may have caused Kerosine to get at motor bearing causing it to be destroyed. The engineer should perhaps have replaced the bearings, but in fairness he might not have realised anything wrong. You really should be experienced with oil boilers to work at them. If you move the burner you could cause the oil hose to leak eventually.
The motor requires the fan removed off it, which can be a problem if seized. It's a delicate job.
The oil pump can be disconnected at the burner end of the wee pipe.
It is a fairly straightforward job to an engineer who has done it loads of times & has all the parts & an analyser to set it all up.

 

[salixarbour]

Hi Best.
Many thanks for your reply.
The CO2 levels do concern me, and that's also why I posted my question.
I'd also read on previous posts about the possibility of the kerosene having leaked along the motor's shaft.
I think the engineers that I know are both away at the moment on Easter hols; I've had no reply to the texts I've sent to them. And when they're back I just know they'll be inundated again with pestering clients like me!
I'm pretty handy with most things DIY and have even build a kitcar in the past! I'm also very careful, and will give this job a lot of repect ... if I'm forced to do it. Once done, I'll make sure the CO2 levels are checked again, once I can get a engineer round! :-o
Many thanks for your advice, Best.

 

[Best]

Problem I find is lots of people say they are great at engineering, but often many do it wrong. If you do give it a go, just be sure you don't alter any oil pressure or air adjustment settings etc.
Take care not to twist the fan out of shape as it will not run straight. I am not recommending you do it yourself, but stating the obvious, isolate electics & turn oil off making sure it can't be turned on again by someone, for total safety.
If you want an OFTEC oil engineer you could try posting a request for an oil engineer on this forum & a local person could help.

 

[SimonG]

If motor runs at different speed it will affect oil pressure which will change combustion. Which is why any self respecting engineer would check combustion with a change like this. If you dont have the equipment to check combustion then leave it alone. Simple as.

 

[Bunker]

If motor runs at different speed it will affect oil pressure which will change combustion.

I had never thought about that but of course, if a motor has been running on grisly bearings and then 'suddenly' on free ones, it will run faster than it was last set up for and as you say, greater oil pressure. Ive always done a FGA after a motor/ bearing change but hadnt clicked the obvious!