intermittant re-ignition whilst running

Joined
3 Sep 2010
Messages
32
Reaction score
0
Location
Ross
Country
United Kingdom
hi all. Can someone give me some advice about my oil fired Boulter classic boiler please. Its a jet burner, with single line operation from the tank and a Boulter oil loop / deaerator, and firevalve fitted in the line outside the house.....when its running and as I stand at the balance flue outside, I can hear the fan and burner running, but every now and then the burner seems to stop roaring and theres no exhaust heat..... for about 3/4 seconds ,however I can still hear what sound like a fan running.... then I hear the igniter "click " then the roar of the burner starts again and theres exhaust heat again. I would describe the problem as a "Intermittant re-ignition" when running. . I have re-set the fire valve in the outside pipe work and its still the same, I will clean the filter at the tank and check for water when it stops raining. there is no sign of dirt or water at the deaerator which is full of oil. Apart from the above problem the boiler runs as normal but takes longer to warm up from cold due to the burner cutting on and off. there is no sign of any smoke when all this happens, the exhaust is clean. Any help would be appreciated
 
Sponsored Links
Obviously the flame is being snuffed out from time to time - the photocell sees this and goes for reignition.
If reignition is unsuccessful then the burner locks out and then has to be manually reset.
It sounds like there could be an oil pressure problem, and the pump needs to be adjusted. Unfortunately you can't do this without a pressure gauge and a flue gas analyser so you'll need to contact someone who has this equipment. Excess air could also cause this symptom.
It is a very good idea to clean out the soot from the boiler in the first instance though.
John :)
 
Try leaving the casing door open to see what happens.

It could be the flue seals.
 
Thanks for those posts guys,
I will try them out and get back with the results
 
Sponsored Links
before I go any further with this thread, I should state that Ive owned this house for 7 years and the boiler has never been serviced in that time, I foned the previous and he never serviced it either , it was installed in 2000, I changed the 2 inline oil filter 2 years ago, its used very lightly as we tend to use the real fire and back boiler to keep warm...Right...Ive removed filters in the oil line and they are clean and free of water, there is a good flow of oil to the burner. I have tried it with the front door off, and this has improved things a lot but not completely, so I want to clean the baffles out in case its backpressure snuffing the flame . I have a manual for this boiler, it shows the baffles but no pic of the boiler itself, theres a plate on top of the boiler...1 foot long x 7 inches wide and its held on with 2 nuts, I assume its the maintenance plate for removing the baffles, am I correct..... next to it is the flue which I can see needs the fire cement replaced as its turned to powder but is not leaking. Once I have removed the baffles, do i just hoover out any soot, and is there anything else I should clean or check while Im in there. Also. will there be a gasket to replace on the inspection plate when rebuilding or will it be a rope re-usable seal? thanks for any more help.
 
Basically you do what you say, at least to start with. The rope seal on the access cover may need replacing as this can be a source of contamination of combustion air. After 11 years, I would think that there will be some very necessary burner maintenance. Nozzle, blast tube cleaning, photocell cleaning/replacing if it is too dirty. also, if fire cement round flue seal is not sound, then it could indicate a problem with condensation which may also affect the flue sealand contaminating combustion air.
 
Thanks for that input Oilhead, I will clean out tommorrow and get back. cheers
 
Hi again guys. I havnt cleaned the boiler out yet due to work but can anyone tall me why it is running fine if I open the cover door at the bottom next to the burner air intake, If I shut the door the burner statrs cutting out straight away, I have marked the orig position of the air control flap and opened it to the next increment to increase air flow slightly but this has made things worse so returned to orig position. It runs fine with the door adjar near the burner, would i be correct in assuming that it must be exhaust gas escaping into the boiler unit housing and drawn back into the burner via the fan and its the unclean air snuffing the flame. While its running, I can feel no leaks by hand or any vis defects. Regardless of the above, do you still advise a boiler cleanout as a process of elimination. Thanks for any help.
 
Usually caused by flue seals or blocked air intake.
It's a minor task to check if a cleanout is needed.
A sooted boiler is often the cause of failed flue seals.
 
before I go any further with this thread, I should state that Ive owned this house for 7 years and the boiler has never been serviced in that time,


I am inclined to say what do you expect?

Tony
 
Thanks for all the replies to this post, can someone here tell me how often a lightly used oil fired boiler should be serviced and cleaned and on average what should I expect to pay? thanks for any help
 
How much its used seems to have little effect on the well being of boilers.

Most would say with an oil boiler that it should be serviced every year during the summer.

As to cost, it takes a little while, perhaps an average of an hour but that depends on its condition and the speed of working.

Local competition and distance from engineers is also relevant. In an ideal world arrange with neighbours for several boilers to be serviced on the same day at an agreed ( reduced ) price.

Tony
 
Thanks for all the replies to this post, can someone here tell me how often a lightly used oil fired boiler should be serviced and cleaned and on average what should I expect to pay? thanks for any help
You are getting contaminated air. This will be due to either a poor flue seal, or an access cover seal. Both of these conditions come with age, rather than use. The access cover seal is easily replaced, the flue seal is more involved.
 
Thanks for that info guys, I gather the flue "seal" reffered to here is the rope and fire cement seal on the top of the boiler around the base of the flue pipe. can You confirm that please ? Can you also tell me if CO2 gas is heavier or lighter than air ?
 
Oh dear!

You are asking questions which are not relevant!

CO2 is heavier than air! But thats only when its at the air temperature!

Heat it up to flue gas temperatures and its lighter!

But all that is irrelevant as the flue gases are expelled under positive pressure created by the burner fan!

Tony
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top