hrm wallstar oil combi

[carl ryder]

can anyone help
our hrm oil combi today decided to lockout and wont reset

it has happened intermitantly ober last few years and have 2 seperate plumbers trying to fix it
they have replaced oil pump , cleaned baffles , set it up , changed oil tank , and the last plubmer has said it needs replacing as ' knackered ' we have psent over £2000 ove rlast 2 years getting no where really

now im not a plumber but reasonable diy and dont like being beaten

ive checked solenoid and replaced plunger ( with one from steam cleaner as being xmas day cant get one )
no differant and defintly pulling oil

in my opinio its not firing just starting to pump then shutting down

we have n heating or water and plumber wont come till 4th jan so am desperate

i dont think its photocell as not firing at all

is there a way of trying control box or igniter as this in my opinion is what it must be but im no expert

any help or advice appreciated

 

[Burnerman]

You can check for a spark if you disconnect the oil pump solenoid coil, and then trying for a start......obviously you have to be looking at the electrodes ( or use a mirror) for this one.
John

 

[carl ryder]

thankyou not sure where to look for electrodes but ill look in moring

i prsume if its not sparking its the coil or control box so i could meter the coil and see if continuity i suppose

 

[Burnerman]

If you want to pull the burner out of its boiler hole, you'll see the electrode tips level with or just behind the nozzle, both being shrouded by the blast tube. The gap between them is usually between 2 and 3 mm.
The spark is actually behind the nozzle because the draught from the fan blows the spark into the oil spray.
John

 

[carl ryder]

thanks for your advice ill look in moring and report on here what i see ( or dont )

 

[carl ryder]

no spark and have metered the danfoss spark generator and it sopen circuit and checked output from control box and 240v there so it looks like coil gone down , being xmas goodness knows when ill get one so frustrating wait now

 

[Andy4444]

Should be an EBI transformer which is standard van stock for any oil boiler engineer.

Why don't you try calling a local OFTEC guy (doesn't have to be but a good start) and offering to buy one and if you really desparate you might want to throw in a "gesture of goodwill".

Just make sure that the spark is not shorting somewhere along the train of electrode leads or the electrodes (sometimes when you remove the ceramic electrodes they might have cracked where you can't see when they are in situ). If you so take them out keep a note of the spark gap and position of the electrodes against the nozzle/behind diffuser.

Where are you located?

 

[carl ryder]

thanks for your reply im in lancashire ive tried plumber we have used and they are closed for holidays its a Danfoss EB14 transformer and ive looked on line and plumbase have them not open till tuesday , im pretty sure its transormer as metered it and open circuit so presume burnt out , if any plumbers on here in east lancashire / yorkshire dales ill pay a good premium for this part asap !!!

 

[muggles]

Won't they need a boat to get to you? Looks a bit floody

 

[carl ryder]

yes its bad up here but we live on a hill lol

 

[carl ryder]

i got a new coil ( and replaced photocell ) and its firing up now

however its still sometimes locking out and needing a reset on control box

there is no bubbles in the oil pipe what else could cause this ?

the only consumebale part ive not replaced is the control box could this cause this problem or any other ideas

 

[Andy4444]

What happened about the transformer?

 

[carl ryder]

i replaced the transformer as old one was open circuit this got it runnning

 

[Andy4444]

An intermittent lock-out on a Wallstar can test the patience of even experienced oil boiler engineers.

You've replaced the cell, transformer, oil pump, solenoid coil. There is no mention of a new nozzle? Have you checked condition of drive coupling? Does the cell have an unrestricted view of the flame? Is the blast tube innards nice and clean to enable good light refraction for the cell to recognise flame? Are the transformer and cell leads failing? Is the burner secure into the combustion chamber and the rubber gasket preventing products of combustion coming back into the combustion air intake?

The only components left are electrodes (did you inspect them for signs of tracking or cracked ceramic?), control box and motor.

Make sure all the oil pump connections on the incoming oil line are absolutely tight and not allowing air ingress into oil pump.

You've mentioned that there is no air in oil line but give the NRV a wiggle and see if you get any champagne bubbles coming through......

This could be a saga!!

 

[oilhead]

And on a Sterling burner, what about the motor capacitor? Also, is there a blocked filter at the tank, or a non return valve fitted at the tank? Lots of people fit them when they shouldn't.