Grant Euroflame 90-120 not firing

[Drfeelgood1]

hello gain, the boiler now runs but when the flexable pipe is connected it starts to cut in and out, the flue is good with no obstructions, any thoughts?

cheers

stu

 

[Boilerman2]

Either there is a restiction in the Air inlet, or a seal has gone between the inner and outer flue
Which flue have you got Rectangular or Round, is it low level or high level or Vertical??

I suspect that flue gasses from the discharge are getting into the air inlet because of a failed seal (more common on round flues)

 

[Drfeelgood1]

hello, the flue is a low level balanced type, the oftec engineer has just left and he ha never come across the flue causing this problem. the burner runs really well without the flex pipe on that draws the fresh air in. inside the pipe it has traces of black deposits suggesting that at some time the burner has been sucking dirty air in thus upsetting the combustion process. the flue is postioned in a very open space on the outside wall, no other buildings for thirty meters or more. its is as thought the exhaust gases are sitting aound the flue and not getting away and almost driffting back into the fresh air inlet and then been sucked in. tomorrow i am going to get another length of pipe and run it from the burner out of the window near the boiler to see if it will run with air drawn from a source other than the flue.

cheers

Stu

Either there is a restiction in the Air inlet, or a seal has gone between the inner and outer flue
Which flue have you got Rectangular or Round, is it low level or high level or Vertical??

I suspect that flue gasses from the discharge are getting into the air inlet because of a failed seal (more common on round flues)

 

[casius66]

Boilerman2's advice is sound I'd suggest in this instance your Oftec guy may need more experience

 

[Boilerman2]

Does your Boiler have a Square Flue Terminal or a Round one?
please reply to this as it does make a diffrence

I think your experience just shows what OFTEC OFT 101 actually teaches somebody with NO EXPERIENCE, what is happening to your boilr whilst not common, is not that unusual, and I am supprised that an engineer who regularly works on oil fired appliances, has not come accross this problem before, if charged £1-00 for each time i found this kind of fault I would now be a very rich boy!!

 

[Drfeelgood1]

Does your Boiler have a Square Flue Terminal or a Round one?
please reply to this as it does make a diffrence

I think your experience just shows what OFTEC OFT 101 actually teaches somebody with NO EXPERIENCE, what is happening to your boilr whilst not common, is not that unusual, and I am supprised that an engineer who regularly works on oil fired appliances, has not come accross this problem before, if charged £1-00 for each time i found this kind of fault I would now be a very rich boy!!

hello again, the flue is a low level square device, looking at it the exhaust pipe in the flue cannopy sticks much futher out than the fresh air intake pipe. i haven't had time to actually strip the flue system down yet but my iinitial thoughts are that due to its design there ddoesnt appear to be an ooppurtuinity for the exhaust gases and fresh air to mix apart from in the flue ccannopy, both pipes as they pass through the flue are solid metal, the induction flex pipe clips on it and does nothave any holes in it. the Oftec chap had seen many flues that have leaks in seals between inner and outer pipes but my sysytem iisnt built like that.

cheers

Stu

 

[Boilerman2]

The front of the terminal should have a clip on air deflector plate, which forces the outlet gasses downward, there should also be a sleeve which fits over the outside of the terminal, which effectively blanks off the air inlet holes at the bottom of the terminal (the holes nearest the wall) are these two plates in place? if only one of them is present, remove the other as well, it is unusual for the square type flues to give this kind of fault as the design is non-concentric, so unless the deflectors are incorrect or the flue is too near to a corner or too close to a opposing surface i.e. facing a wall or fence thent this is a very strange problem