Wallstar cutout - can wind cause it?

[willemmOO1]

Thanks Agile

I don't need to cycle to keep fit - my boiler problems get me up and down stepladders to keep it going and IT is only 12 years old.

Went three times again today (now 10 pm) at roughly 3 hour intervals, for no good reason and I have little doubt I'll wake up to a cold house in the morning. Time to get the 'expert' in to sort it out.

Clicking sounds from within cabinet while burning might indicate the Control Box on the blink, but then again it might just be doing its normal job and there's another gremlin in the works that needs sorting.

If there's one thing I dislike more than anything, it's unreliability. The problem is whether it's the machine or its serviceman/fault-finder that's unreliable. Trial and error - with lots of both.

 

[oilhead]

Clicking sounds from the control box are usually allied to flame sensing, or rather lack of flame sensing. Fuel supply is still my favourite, but if it is running lean, then 'blue flame combustion can also cause it.

 

[oilhead]

Clicking sounds from the control box are usually allied to flame sensing, or rather lack of flame sensing. Fuel supply is still my favourite, but if it is running lean, then 'blue flame combustion can also cause it.

 

[willemmOO1]

Thanks Oilman
From observations it's becoming clear that flame sensing is the culprit. Last Wednesday with several cutouts was in cold but very damp, misty, drizzly and gusty conditions. Have had none since in spite of sub-zero cold and when on, no clicking from control box.

Am now looking for a new serviceman but all seem to be busy for weeks ahead. I found an interesting web ad for boiler service listing these:

Replace burner nozzle
Clean the blast tube and heat exchanger
Check / test solenoid, photocell and oil pump pressure
Clean, lubricate & adjust controls as required (incl motor and fan)
Test the CO / CO2 ratio and adjust inline with manufacturers instructions
Test flue gas temperature.

At most my services have only been getting the first two. How do other service technicians see this check-list - is it the norm or laid down by OFTEC?

 

[Burnerman]

Replacing the burner nozzle is a good thing on a yearly basis (although in real life they can behave for much longer than that).
Cleaning the blast tube and combustion chamber is essential (I have a compressed air supply for the complete burner, and a good vacuum for the rest).
Cleaning the photocell is essential, but I'm not sure about testing the solenoid - normally they work fine then start to fail as the burner heats up.
Setting the oil pump pressure is essential.
Cleaning and lubricating the controls? Not sure about that one! The motor bearings are sealed, and the fan couples onto that.
A smoke test / flue gas analysis is vital to set the CO2 ratio correctly.
Just a wee thought concerning balanced flue appliances that get huffy - I find that running the burner with its cover off, thereby drawing combustion air from the room can sometimes point you in the right direction. Lets hear what the others say, but I wouldn't alter the flue.
John

 

[algas]

I installed one of them at my own home when we didn't have gas to the village & mine used to do exactly the same as yours 3 times one cold xmas day if I remember, it was set up correctly, I changed all the parts under the guarantee & it still would not behave, in the end I put it down to possibly having a small leak & air getting into the supply as it would fail on first firing in the morning but sometimes it would go during the day so in the end we got gas to the village & out it went.

 

[willemmOO1]

To Burnerman, thanks, yes I agree about nozzle though I guess once a year for its low cost isn't a bad thing - better safe than sorry.

I wasn't sure about the oiling procedure either, and as Wallstars aren't balanced flue being exterior-mounted flush to wall, mine gets huffy in cold, damp, windy conditions.

Algas - you've described exactly what I've been suffering for many years but I'm beginning to feel that with proper setting of CO2 with a fine adjustment for cold/damp etc they should cope. HRM insist that they do.

Once I can get a well-experienced technician to give mine a thorough test/adjust service I hope HRM are proved right as I have no gas alternative.
Problem is service is seldom done in the conditions that cause the fault, so any adjustment will depend on experience, and not just by the book.

 

[willemmOO1]

Hi, I'm back to pick your brains again. Bear with me, this takes some explaining.

In spite of –6c cold, occasional damp/wet conditions, has run perfectly without cutout for 9 days. Today, gusting 20 mph NW but +5c and dry, cutting out. Flue faces west.

After reset, burner runs then stops but doesn't cut out. By turning up boiler stat it fires up only to stop again, and will continue doing this but I won't increase stat beyond its Max setting. Call light will remain on for several minutes before firing up again.

When not cut-out, call light on but no burner on, can hear from room side of cabinet a slow clicking sound. Might this be the boiler stat?

When burner on, from within cabinet outside can hear very rapid clicking, but unable to see control box contacts moving as not all are in view. Have replaced control box but same clicking sounds, followed by cut-out. Transformer and solenoid both new.

It's clear to me that 9 continuous days of faultless use, broken by only by gusting winds leading to confusing burner off, burner on, with clicking of contacts, and cutting out is directly related to wind, especially if from west, opposing flue emissions enough to cause cut out.

Have tried fitting a 5" bull-nose cowl but just offering it up to flue caused cut out.

Surely 9 continuous days of trouble-free use, no smoke, a clean photocell, indicates a more obscure problem, unless as my first post implied, Wallstar wall mounted systems are prone to cut-out by wind, in which case there is no solution. Any further comments welcome.

 

[oilhead]

You have two different problems. Thermostat demand without start up is unrelated to your lockout.
Or maybe........
Do you have periods of low voltage mains?
Given you are discounting the obvious, we start clutching at straws. The Satronic box does not like voltage below 220volts

 

[Danoil]

I had a wallstar doing this last Christmas Eve, it's almost like the thermostat is playing up but in my case it was the bi metal strips in the control box. I replaced this and it's been no trouble since. These sterling burners have had problems in the past with the control box going wrong and taking out the spark generator (and vise versa) and it was recommended to replace both at the same time. Most oil engineers will keep both of these parts in the van. Hope this may help you.

 

[willemmOO1]

Hello Oilhead

I wasn't aware of control box sensitivity to low voltage, depends on where one lives I suppose as to what is typical for locality. It so happens mine is stable at 240v during day, then there's a grid switchover at 23.30 when it drops to 230v so still well above the 220v threshold.

What I think may be key in my observations is the clicking. A fast clicking when boiler is struggling, but fewer or none when not. Having replaced control box with brand new one and still getting clicking seems to indicate somewhere else?

This behaviour lasted from early this morning until this evening when winds now light, burner running 'normally' including a half-hour water heat-up just to test it further.

Doesn't my attempt to fit a bullnose cowl with downfacing outlet bigger than flue vent so causing a cutout lend weight to my argument that resistance to flue emissions whether by wind or a device leads to cutout?
I really am clutching at straws as they are all I seem to have.

 

[willemmOO1]

Hi Danoil,

You've rather thrown me there. Isn't control box sealed? What are the bi-metal strips you refer to?

I have a serviceman coming next week and would like enough know-how to present to him about this saga of mine, now in its 10th year.

So far if any suspected problems with control box it's been replaced. No mention of bi-metal strips possible cause.

 

[Danoil]

Sorry, my fault, the bi metal strips are in the control box and yes as you say these are sealed. I had not read posts properly to realise you had replaced the control box so my 'advise' was no such thing! My apologies.

To be honest from all you have wrote it does sound to me the burner needs a damn good set up ie, electrodes positioned correctly, photocell can 'see' enough light, pump pressure correct, and co2 adjusted correctly. Also please do take notice of what others have said about joints in the oil line. Especially the fire valve/NRV as these are cause for for many problems drawing air and letting oil run back. Also, as more as a precaution make sure and filters/strainers are new, or cleaned as any resistance of oil will not help.

 

[oilhead]

The only time a control box will take out a transformer is where it either keeps the power to it through a faulty switch, or where it constantly re-ignites through intermittent flame sensing. If an intermittent rated transformer is operated past its rated time ( 20%, 33% or 50%, then that will fail and may take out the contacts in the control box.
Obstructing the flue will stop the burner eventually by restricting the air intake. A burner can only replace the air it can exhaust, so enriching the mixture to the point of extinguishing it. No oxygen-no flame. If you want to shield the flue, then you need to give it room to breathe, and this means you need a shield substantially bigger than the flue outlet so that any wind cannot by pass it.

 

[willemmOO1]

Thanks Danoil, and once more Oilhead.

Cutouts yesterday were horrendous - lost count over 30 or more, yet by early evening it settled down, lasted through night until early hours about 5 am I guess. I was up at 7 am, reset 3 times up to 9.30. This lasted 4 hours. In perfect conditions, no wind, sunshine, cut out 13.30. Reset ran OK until call light off. Quite bewildering but evident that while wind can cause cutouts, they happen under good conditions too.

Oilhead, I found your post about 2 years ago "Your flame is not blue, it will be yellow/orange. It is only the viewing window that is blue. If the flame was blue, the photocell would not pick up the light. A grossly overaired flame can result in 'blue flame' combustion and causes flame failure lockouts; the blue is very slight and just forward of the nozzle and barely noticeable to the naked eye"

As Danoil says, system needs a damn good set up which is what I hope it gets next week.

Many posts refer to NRV - is there a test for this or should it just be replaced? From all the very helpful info many have given me I want to use this to check with the OFTEC technician who's a stranger to me, to make sure he covers all possibilities.