Myson Velaire boiler deadish

[The Natural Philosopher]

This is on behalf on an elderely friend, who has one of these that is suffering from 'i'm dead with a lockout'.

Resetting doesn't fix it, and a bit-of-cowboy plumber looked at it and pronounced the igniter dead, and the pump leaking and suggested a whole new burner assembly.

He claimed the oil from a leaking pump had dripped on the igniter transformer and shorted it. Oil is however an insulator.

He also claimed it hadn't been serviced for years (it had).

Certainly there was no sound of sparking although the pump did spin up.

Anyone got any useful advice to offer in terms of what may have gone, what it should cost to get it fixed and where to get parts if local plumbers do a teeth suck and start talking silly money? Or 'cant get the parts for that mate: You needs a new boiler'

Heat exchanger looks OK ish.

[Tricky Dicky]

Cannot offer any advice but can empathise with you. Our last house had a Bo sch Greenstar service boiler which developed an intermittent fault causing it to trip out usually on start up and very rarely in mid session. At the t ime we had a service and maintenance contract with Eon. I told the first se rvice guy it had all the hallmarks of an electronic issue, but no. So said the procession of other guys who turned up every two weeks to replace some component or other. Eventually having replaced just about everything except the heat exchanger and the PCB an engineer turned up and announced after m uch head scratching and as a result of a process of elimination it had to b e the PCB. This was duly replaced and problem finally solved. Fortunetly I was retired at the time but would have been mightily annoyed at the time of f work the repair would have required not to mention the inconvenience of t he heating being off. The only positive from it was that we virtually ended up with a complete new boiler which the last service engineer grudgingly p ointed out to me.

There got it of my chest!

Richard

[The Natural Philosopher]

Yeah. Been looking at the damned thing and a new burner assy looks like £500+.

The guy is 75, semi retired (actor) and has a cold house and precious little money to spend.

Nothing has been fixed for years there's a dicky motorised valve that leaves the boiler on all the time, and even the immersion heater ist working, either..

Doesn't qualify for a grant because he's not a scrounging benefits bastard.

Maybe a S/H oil system boiler is the way to go.

[johnjessop46]

Can you tell us what make of burner you are referring to? Myson used a numb er of variants, most common being Riello. Is the burner enclosed in a red m etal box or is it "bare". I'd make a stab in the dark that it's a bare Riello (same thing inside the red metal case if thats what you have). If my guess is correct the burner sequence control is a grey plastic box on top of the burner unit. This box controls everything and contains the igni tion generator, holds the flame detector photocell etc. If the photocell has suffered heat damage or has gone short circuit the seq uence control will "think" a flame is present before it should be and go th rough an abbreviated sequence to "false light lockout" No ignition spark wi ll be produced during the run to lockout. If you have a different model of burner the story will be slightly differen t so check and come back. NB the photocell is a simple plug in unit. However if the problem began wit h an oil leak that needs dealing with pdq.

[The Natural Philosopher]

I'll take a picture tomorrow and post it up somewhere. It looks older than the generic Riellos I have seen

Now that may be a thing to test.

Well I am not sure that that was the original problem. Its always smelt a bit of oil, but then many boilers do....

If I take a picture, would you be able to help me get to some kind o0f diagnosis?

>

[johnjessop46]

If you can take a picture I'm happy to try to help. The three most common o il leaks on Riello burners are the air slide ram (if fitted), the pump shaf t (often accompanied by a failed pump end motor bearing) and embrittled oil line flexy hoses especially those with external metal braid. Oil flexy hos es should be replaced every few years.

[The Natural Philosopher]

Ok. I've got a hospital thingy to get through tomorrow morning, but will try and get some pikkies so at leasts it should be possible to ID the burner unit and work out what spares are available.

I think your comment about a broken flame sensor causing immediate lockout has struck a chord.

It doesn't even seem to want/try to fire up. Pump and fan spin up, then it goes 'click' and locks out. And wont reset5 for ages.

[johnjessop46]

Hope your hospital visit was ok. I should perhaps have suggested disconnect ing the suspect photocell and trying a reset. If the problem did lie there the sequence would run up and the burner would ignite but after a few secon ds it would lock out as the flame would not register.

[The Natural Philosopher]

Oddly enough the friend found a local plumber who came in and said 'bullshit: photocell is simply all tarred up, and it all sprang to life.

[johnjessop46]

I'm glad your friend has warmth again. It's often tricky to find a reliable guy to look after oil fired domestic heating plant so I trust the guys number is writ large on the boiler.:)

[kineticworld.ps]

If you want a pdf of the Myson Velaire maintenance manual you can download it for nothing from my website: www.peterscott.website Look under Downloads

Peter Scott

[Mains2Drains]

replying to The Natural Philosopher, Mains2Drains wrote: ..... And the reason for the photocell being all tarred up is: A result of the combustion process failing. All fuels require a Stoicimetric mixture of Fuel to Air ( circa 1 part fuel to 11 parts air). Failure to correctly set this results in "incomplete combustion" and a build up of soot/tar deposits. Setting the correct oil pump pressure (measured oil delivery) and air damper position (measured air delivery) is paramount for a complete combustion and clean burn.

Has anyone got the Myson "additional burner data sheet" that's mentioned in the owners/service manual ? knowing the manufacturers expected pump pressures would be great to know as the "industry norms" are ok but not always exact enough for a good clean burn.