Worcester Danesmore RS 20/25 LOCK OUT

[farghi]

Good Morning All
I have returned from working away to a none working boiler, the wife was highly delighted ! That and the World Cup on every channel !!
Cleaned tank master filter, pump filter, and nozzle gauze filter. Tank has fuel, was firing after resetting lock out intermitently for 4 minutes, now is refusing to fire.
After reset- fan on, sparks, no lighty! no oil through pressure port take off either.
When it was firing yesterday, after 4 minutes a "relay" chattered in control box and the fuel stopped.
I think I may have identified the fault - control box, however does anyone have any further suggestions?
Can the points in the relay be cleaned or reset?
Thanks for reading
Farghi

 

[Burnerman]

Its probably best just to leave the control box alone, but a likely fault will be in the coil that sits on top of the oil pump.......when this is energised, it opens an internal valve inside the pump, to let the oil through.
John

 

[farghi]

Thank you will look at the coil will check a voltage is being sent to coil with multimeter

 

[Andy4444]

Check the resistance of the coil when burner locks out. If the solenoid is failing it will register open circuit on your MM. When it cools down you will probably register measurable resistance again.

Is it a Danfoss oil pump? Solenoid resistance should be circa 2.4k ohms if ok.

 

[farghi]

coil energises, removed solenoid plunger, is it meant to move ? tapped it and re built. Now on start up solenoid clicks and boiler fires. Still running after 1 hour. May need to change pump plunger valve assembly

 

[farghi]

ooops missed Awowen post, ...... boiler locked out again. I suspect plunger in Danfoss oil pump. or control box or both. No click from solenoid before I took plunger out now clicks and allows oil flow, however with boiler now locked out and me too tired. Will check tomorrow
Thanks for the help so far, I will no doubt be back
If I do get a new control box (Bentone Oil Burner Control Box TF832.3) do I need a new photocell as well?

 

[Boilerman2]

This is getting good!! in an attempt to save money this one will soon spend more than if had got a Service engineer out!!

 

[farghi]

Boilerman2 thanks for the vote of confidence, I do like your words of encouragement. With the cost of replacement parts being small and readily available for this unit I don't mind spending out for replacement parts, what I do mind is paying for a service technician to do exactly the same as I am doing.
I have had in the past witnessed a technician replace parts until it worked, no different to what I am doing.
I don't like being beat by a lump of metal and plastic bits.
So I shall plod on and attempt to educate myself with the guidance from your goodselves and others.
Difficulty in finding an oil technician in Bridgend South Wales doesn't help either

 

[Burnerman]

Obviously it's difficult to be accurate, but a few pointers maybe......the control box relays will click due to several causes, one being the photocell switching due to the flame darting about, and that doesnt automatically mean it's faulty.
In fact that controller ifs a particularly good one, in my opinion!
The solenoid coil is the main suspect, as it is on the Danfoss pumps, and they fail when they heat up .
The trouble is, a pump comes complete with coil and valve, which are expensive to buy separately.
John

 

[farghi]

Burnerman Thanks fo the pointers will look tomorrow morning

 

[boilerdoktor]

my guess and its an internet guess is the solenoid!

thing is its all very well to sort your boiler out but can you test the co 2 emmissions after and set it up right?? whats the o2 ratio? ( your looking between 30 -40 % ideally) co 2 is nice at between 10 -11

do you have a co monitor?

i would probs call WB out if you cant get a local engineer-fixed price fix and they will set it up for you!

 

[farghi]

Internal lugs on plastic Bentone drive coupling stripped on motor shaft, so will fire up short amount of time due to friction in drive coupling, but as it warms up the coupling spins on oil pump shaft and stops oil delivery.

 

[Burnerman]

A nice easy fix!
Always worth keeping a spare in stock, and a coil isn't a bad move either. Often enough, failed drive couplings make themselves known by the racket.
John

 

[Boilerman2]

Internal lugs on plastic Bentone drive coupling stripped on motor shaft, so will fire up short amount of time due to friction in drive coupling, but as it warms up the coupling spins on oil pump shaft and stops oil delivery.

Well done - that is a fault that has fooled even professionals good work!

 

[farghi]

Yes the plastic drive coupling..... 98p ....now running fine.... in the words of Mutley the Dog "Rassen frassen plastic coupling !!"