Trianco Eurostar boiler problem

[Jacey96]

I'm looking for some advice on a frustrating problem I'm having with my old Eurostar 50-60s oil boiler please? Although it's old, most parts needed to operate are now new.

The symptoms indicate a broken burner motor or oil pump. I wrongly assumed the motor so I ordered a new one only to find that once removed it was actually the fuel pump that was stopping the motor turning therefore I replaced the pump also. The controller was replaced only a few months ago. It then started up fine.....and I was feeling pleased that everything seemed to work. BUT once the stat turned off the burner (or even if it was turned down manually) the motor wouldn't run again and lock out occurred. The motor did feel quite hot. If left for a day, it would start up again but only until temp reached (or turned off) and will not restart (locks out). So (re the hot motor) I replaced the capacitor but the same thing happened. Checked the oil pressure and that is correct at 110psi.

So new motor, pump, controller (inc photocell) and capacitor installed, fan wheel is clean and unobstructed; when the motor runs at first start, it all seems to run well. Does anyone on here have any ideas on what I could try next?

[btw There was a discussion on something similar back in 2010 but not exactly the same so thought it best to try a new post.].

Thanks in advance. JC

 

[Exedon]

Which burner Trianco used more than one!
Dependent on burner oil pump slightly misaligned?

 

[Jacey96]

It's a Riello G5 BF.
Yes I'm now thinking the same as initially I connected the pump to the motor but then couldn't get the oil feeds nuts to bite in the pump due to rigidity of the pipes so had release the pump, connect the pipes and then attach it to the motor.....and I recall is was all quite taute / tight even though the fan wheel seemed to move ok.... it probably should move more freely than it did.

 

[Exedon]

We have just moved several of those burners on
As its a new motor should be no problems there.
Drive coupling in good nick?
Line up pump carefully don't over tighten!

 

[Jacey96]

OK thanks. Yes it's a new coupling. I've just removed and reinserted the pump. The fan wheel moves freely but not as freely as when the pump is not connected - which I guess is expected. I'll try and fire it up again tomorrow.

Even though the pump is aligned I do feel there is a lot of sideways tension on the pump where the oil pipes are connected so if it fails again I'm planning to loosen or undo the pipes just to see if the wheel moves more easily. If so then the pipes will need adjusting to fit more easily - not something I'd want to tackle really so hoping re-seating it (with less tightened bolts) works! Thanks for your advice.

 

[oilhead]

The oil pipes are sufficiently malleable to be able to be adjusted to relieve any strain. i've always fitted these to the pump and then connected the top case end. it sounds more like the pump is fitted too tightly into the motor. The grub screws only need to be nipped up to eliminate rotary movement.

 

[Jacey96]

It works fine now.....what a relief! [I didn't want to say that yesterday in case I was being premature as I expected a lock out again!]. So you were spot on re the grub screws - thanks very much for that advice. My 28 year old boiler is reborn.