Thermecon 60/80 oil boiler, Ecoflam Minor1, Delta VM1

[needsmust]

Hi folks,

Please go easy on a curious/desperate amateur.

I've been in this chilly house for 18 years with this set-up providing plenty of heat; the boiler instruction book says 1995. The ageing radiators were flushed about 5 years ago and work fine.

I got a top-up of oil just before Christmas (without running out) and thought I'd add a bit of the Hydra Vulcan additive (which I've used before, but not last time). The burner locked out a few times since then, and on NYE it stopped starting altogether.

Way back in Covid lock-down, I'd had some problems with the fan sticking. The nice man who used to remind us it was time he popped over with the Hoover and his probes and nozzles hadn't been in touch for a while, and we couldn't raise him on the old numbers, nor any other OFTEC person for at least several cold days.
I imagined that I was probably heading for a new burner eventually, and in a nothing-to-lose situation thought that I might as well tear it all down and give everything a clean.
It was quite fun (and would have been more so if there wasn't the threat of running the house on coal and the immersion for a fail). There weren't too many components, and in a fairly OCD way, I pulled apart the pump, marvelled at the mechanism, and ungummed everything until all was spinning freely and quietly. I took apart the motor and saw that all was clean and good there. I got a toothbrush out and cleaned all the rest - fan, electrodes, photocell, oil valve, blast tube. I had a spare nozzle our engineer had left and popped that in for good measure. I ended up with the cleanest 25yo burner in the world, and better than that, it all worked a treat.
I even took a little bit of soot (there wasn't too much) from the boiler before getting Mr OFTEC round for a proper service.

A year or two later, I'm now a bit less scared of the burner, but another dismantle and clean hasn't got it working. Out of desperation over the bank holidays and in the absence of anyone available in the area for another week or so, I've been poking about in a way I'd expect to attract criticism for on here. I've checked the in-line filter, pump filter, cleaned the magic pump discs, primed it, and replaced the nozzle.

This is what happens:
Fan spins nicely. Purges a few seconds.
Spark looks good (the cover where the transformer mounts can unscrew and hinge up to take a peek).
I think I can feel/hear the coil moving the valve, and if I uncouple the tube from pump to the nozzle holder, oil gets pumped out at a fair rate - several ml in the second or two before I shut off the power. No debris. When all connected, locks out after 3-4 seconds.
Some fuel is getting to the nozzle holder; there's a new nozzle and a little on the blast tube, but only a smear - the inside of the boiler isn't wet with oil.. No ignition.
I've tweaked the electrode positions a couple of times but they look just as the book suggests.

What I don't know:
Why it happened - could the addition of the Vulcan have dislodged some muck - if so, why hasn't a good clean helped? I have a bunded plastic tank just a few years old.
How fast the oil should come out of the pump - I can't measure the pressure but haven't ever touched the pressure adjustment screw on the pump and it gushes pretty freely down the bit of plastic pipe I put over the pump outlet to test.
How much oil I should see from the nozzle in the few seconds before lock out?
How the photocell works - I guess it allows continued oil flow if it sees a flame (it's clean).
Could the controller be on the way out?

Most importantly - should I just give up and get an Ecoflam Max1 as a direct replacement and wait for an OFTEC guy to commission it?

Many thanks for your collected wisdom.

 

[Burnerman]

If there is no ignition at all, maybe the photocell thinks that the flame is already there?
Give it a wipe over, make sure it can see the flame and try again.
What control box are you using?
John

 

[needsmust]

Hi John,

That was way quicker than I hoped.
The photocell is spotless, I don't hear that sound of a flame that we all love.
Control box ruthlessly German (it says here): LANDIS & GYR LOA22, if that means anything to you.
Many thanks,

Mike

 

[Burnerman]

Hi Mike
As you are aware, when the burner starts up it goes through a purge period where the motor spins, the ignition spark is present but the oil is only switched on after around 8 seconds or so.
The burner should light, the photocell sees the flame and instructs the control box to keep the oil flowing, the ignition spark is switched off.
Therefore I think you need to determine if electricity is flowing to the solenoid coil on the oil pump ( voltage sensor tools are available).
Any spurt of kerosene from the nozzle would indicate the pump valve is working......the pump solenoid controls this.
It could be worth opening the control box and looking ( and sniffing) for any burnt components inside!
John

 

[needsmust]

Good plan John.
My suspicion is that there's no flame at all for the photocell to see. I can hear (and feel) something at the solenoid, and as you say, it's hard to picture any oil getting to the nozzle otherwise. 8 seconds sounds about right, I might time it.
The control box seemed a bit sealed to a beginner, but in for a penny, in for a pound - I'll have a go in daylight. There are no trails of smoke though, and it seems a bit fishy that the problem started just after new oil.
Advice much appreciated. Will report back tomorrow.
Mike

 

[Burnerman]

I use one of these to sense if voltage is heading down the cable from the control box to the solenoid:

LAP AC Non-Contact Voltage Detector Pen 1000V AC

Order online at Screwfix.com. Offers high quality performance for the non-contact detection of AC voltage. FREE next day delivery available, free collection in 5 minutes.

www.screwfix.com

I also have a pen shaped device that senses the function of the magnetic field within the solenoid coil - for the life of me I can't recall where that came from!
Be lucky
John

 

[needsmust]

OK John, an update. (spoiler alert - no joy)

Timings are about as above, and with the coil disconnected, I got 240v across the connector after about 8 seconds, so that looks ok.
Emboldened by your sensible advice to have a go at the controller, I took it apart. What a little jewel of a device this is! - lots of mechanical levers and electrical contacts, but nothing obviously broken or blown. I was able to manually move and click the various contacts and plastic levers, and bits of copper clicked and sprang back and forth in a reproducible way with the reset mechanism. I sprayed it all with contact cleaner and put it back together.
While I was there, I saw where the photocell wires attached and slung the multimeter across - the numbers flicked from a few ohms to a great many ohms as I covered and uncovered the cell, so that looks ok.

I tried it again, but no joy. Again - fan spins, spark good, a little oil on the burner tube but not enough to wet the inside of the boiler.

So now I got risky. The boiler is located in a brick built outhouse adjacent to the kitchen. I found a fire extinguisher, took the burner out still connected, pointed it outside and fired it up, with the missus on strict instructions to cut the power if we had a flame.

No flame. Impressive spark, and a spluttery dribble of kerosine from the (new) nozzle.

So - not enough pressure to atomise, but why? Is there a problem with the nozzle holder? There are wires to the back of it from the controller (2 common yellow and 2 red) - is there another valve in here that isn't working? The only replacement nozzle holders that I've seen on Google don't have these...
I also worry that I might have mucked up the pump, but with the outlet pipe disconnected, the oil flows freely out. I've even got a tiny bit of weep here now since mucking about - might need a new olive - but it suggests some pressure (and that the valve works).

Things to try that might not work:
Nozzle holder £50, controller £60, coil £30, pump £100... (none of which look quite identical to the vintage that's on there) or a whole new (more efficient?) burner for £350.

All this diagnosis and experimentation is quite fun while the weather's not too bad and I've got coal and hot water, and I hate to admit defeat, but I'm thinking that this Max1 looks more and more tempting...

Your advice much appreciated - whether to persist or pack in. Either way, I can't seem to get anyone qualified out until next Thursday.

Cheers,
Mike

 

[Burnerman]

This is the sort of time I wish others would chip in.......!
I'm a bit confused as to the wires at the back of the nozzle - I'm not familiar with those and haven't seen them on a Minor 1. Is it possible for you to post a picture?
I have seen a separate valve there but this is purely mechanical and stops a dribble when the burner switches off.
Just now I would suspect low oil pressure, and this can be down to a motor spinning slowly,. a faulty coupling between the motor and pump or a blockage somewhere.
Do you know what the oil pressure should be?
John

 

[oilhead]

When you talk about dismantling the pump, do you mean the oil pump. Your description of magic discs and VM1 seems to support this. If that is the case, then there is a good chance you have goosed it, and whilst there is oil there it is not at the right pressure. In all my time, I have never dismantled an oil pump apart from removing the cover over the internal filter. You wil probably need a new pump.

 

[Burnerman]

For sure, an oil pressure gauge is going to be essential now......some of the other Minors run at 12 bar I believe - bloody high!
John

 

[needsmust]

Thanks both,

John, see the wires at the back of the nozzle holder, you can just make out the 2 yellow which feed to the control box, also 2 thin red wires in that sheath that you can also see in the box, 1 common with a yellow (terminal 8 ). Photocell goes to 11/12, ie 2 leftmost terminals. (apologies for upside down photo of wiring diagram, but it reads L-R like the wires)

The book says pump is set for 11bar at the factory. I've never touched the adjustment screw but don't know about past servicing (which I guess will have been mostly about getting the air mix right).

Oilhead,
You really should pull one apart just for fun, it's a very elegant design. The first photo is with the cover off and discs lifted, the second photo is the underside of the lower disc, both with the filter in place. Third all apart.
When I did this a couple of years ago, there was gummy residue between the discs which was causing the pump/fan to stick. I thought it was ready for the bin and had nothing to lose by pulling it apart and finding this mechanical wonder. Only really one moving part - the little ring in the middle set eccentrically from the gear on the shaft. Worked beautifully afterwards.

Thanks for your interest,

Mike

 

[needsmust]

I should say that I am inclined to agree that the pump is at fault. There's plenty of oil spewing forth when the line to the nozzle holder is disconnected, but I have no pressure gauge to measure directly (although I did do a quick search on BES). Those magic discs do show signs of wear too.

I'm a little worried that it will end up being a Trigger's broom if I start replacing significant bits like the pump. I also have a wait before anyone sensible can help (with a gauge and a sniffer and an oil brain), and then might have another wait for bits. What about that Max1 guys? I could have it in and running factory settings until someone can commission it properly....

 

[Burnerman]

Its a shame that it is the wrong time of the year for experimenting with these things!
I'm still unsure about the electrical connections in the nozzle area but looking at the controller diagram it would seem that it is suitable for a 'soft start' technique which may play a part here.
I have to suspect the pump too - 11 bar is one hell of a pressure (100 to 140 psi being more like the norm) and it would have to be in perfect order to deliver this.
Sticking a new burner in would definitely sort things, but it would need commissioning too.......overfiring will destroy any baffles that are in there in pretty quick time.
We'd appreciate any updates you may have!
John

 

[Exedon]

Having read through the thread few thoughts
I've set up ecoflam burners since they were called monoflame got to say 11bar sounds high unless burner was set up for gas oil?
That would also explain wires to nozzle holder pre heater?
I would suspect oil pump now shot.
I now no longer do repair work personally (have a full time oil engineer) but this sounds like type of job where we would stick another burner in.
As we change 2/3 oil boilers a week we tend to have a fair collection of decent second hand burners.
Whatever way you go you now need someone with correct equipment to re commission.

 

[oilhead]

I read your comments and should qualify my comments with the fact I never took a customers pump apart as I knew what to expect. These pumps work on a tight tolerance of metal parts and contamination wears these parts, The last thing a service technician needs is a call back to something he has no confidence in. If you are working on your own gear and it fails, it's only you that is inconvenienced. The cost of a new pump with warrantydoes not justify 'fettling'.