Wind 'still' blowing out the gas on my fridge

[Plasticman]

Ok Ive read throiugh the lot.
You have fridge fitted with the stainless spiral fitted (this baffle slows the exhaust gases and creates turbulence in the flue, if its not fitted then the gases leave too quickly and before their heat is absorbed)
The black metal 'lazy t' fits and I take it that when fitted the outlet points up appx 45' and the other open end is pointing downwards,
So far so good then.
metal flue pipe.flexi or whatever up to the plate that affixes the van (top one in the picky) The other side of this plate has a small hook bit at the top, hang the rubber flap off this then fit the flue cover with electrolux on it (btm picky) and thats it.
With this set up you can blast the fue with an air gun it wont go out, the flap will close firmer,
It may seem that the flap is completely closed but its not quite, and the hot gases move past it no problem.
have you got a vent/drop out hole under the fridge, I know my devons had them there and they caused probs , they had an ally plate under but this was to stop road debris and water firing up there.
has the burner got the mica/and foil cover in place as whilst its not meant to be a seal it should be a reasonable fit .
I would be inclined to rule out the gas v/v and as has been said the t'couple is also a suspect, they should only fit in a certain position but without seeing it in the flesh hard to say if its right, certainly if its borderline then it wont like an interupted source of warmth (bit like me really )

On another note on a previouse van which had replacable gas cyc's as opposed to leisure tank I did get problems when the cyc was was about 1/4 full, soon as I stuck a new cyc on it was ok.
you ever get near leeds then Id happy go over and through it with you
mike

[Cruz]

I still think the modern flue kit is crap, which is what I have fitted at the moment. And the old style vent is far sturdier and it's steel too rather than crappy brittle alloy and plastic

http://i1133.photobucket.com/albums/m58 ... CF0488.jpg

I have a gas drop vent but nothing much seems to blow in. There is a metal shroud around the burner area but it's in no way a tight seal.

In a couple of weeks I will be fitting the old style flue vent so when I do the fridge will come out and I will take some pics of the burner, thermocouple etc. That way you can see any problems I don't know about....if you don't mind of course

http://s1133.photobucket.com/albums/m58 ... 90/fridge/

[Plasticman]

bugger, theres every picky but the one I want to see, hmph, typical, Old system works well, , I am assuming that whilst I can see the metal cover around the whole burner assembly is there its the small square one thats important, anyhow I dont think the problem is caused by wind blowing down the flue,
Its one of those problems like the thread on high oil use that I just cant resist getting involved in, its mechanical it has a task to perform and its fun deducing why it does or doesnt.
I get up into your country on occasion , well I stray to skipton and thence clayton le moors so I supose it counts, will shout you as and when
Mike

[Cruz]

Clayton Le Moors? I wouldn't wish that on my enemy. I was brought up not far from there in Oswaldtwistle though

Which photo did you want to see as I may be able to pull the fridge out without having to remove it completely

I have had the fridge out on a very windy day, parked it with the wind blasting against the fridge side put some tissue paper down behind the cupboards. It didn't move.

When I have the problem you can hear the wind blowing on the burner and see it bending until it goes out. Thats why I assumed it was coming down the flue because I also covered the flue vent completely during the test and it stayed lit.

[DentedDevon]

The "Lazy T" is what stops the fridge blowing out !

How ?

If you look through the top part of it you will see that the vertical pipe sticks up into it. This creates a venturi.
Blow through the top pipe , air speeds up at the restriction , lowers pressure at that point and draws air up the vertical pipe from the burner and out through the open end nearest the back of the fridge.

MOST IMPORTANT that the open end of the top pipe (nearest the back of the fridge) is not obstructed.
If it is blocked or restricted the wind blows DOWN the vertical pipe to the burner and out goes the flame!

Possible causes of blockage / restriction:-
Wrapped up in insulation mateial.
Badly fitted so Lazy T is pushed against back of the fridge.

[Plasticman]

The black metal 'lazy t' fits and I take it that when fitted the outlet points up appx 45' and the other open end is pointing downwards,

He reckons not or not checked?
mike

[Cruz]

DentedDevon you are right, though a Lazy-T is more like 30 degrees than 45

I have a spare lazy-t on my bench and in true geek style I have just blown through it and no air went down the vertical pipe. It blew through the angled part of the pipe. If I block the angled part with my palm the air is redirected down the vertical pipe which would take the wind towards the burner.

If the wind is coming down the flue surely the fridge gasses will be blown out the back of the lazy-t and into the van?

I will check to see if my Lazy-t is fitted correctly and then park the van in an exposed place to check if the flame still get's blown out the next time it's windy. I am definitely changing the outer vent to the old style one though



I have made a geeky diagram of how it works based on what DentedDevon suggested and my own highly scientific experiment

[Plasticman]

Thats correct, you could block ther flu for an hour and youd not die or notice any thing, you get the odd gust and so very intermittantly the flue gasses will cease to exit the van but i doubt youd ever quantify the ammount.
mike

[Cruz]

I doubt any gusts will enter the flue once I fit the old style metal vent

[Plasticman]

well found some picks I took of one I did ages ago,wether they help or not I dont know but it shows how much crud lives in there and why they need looking at.
first pick shows what should be there

this with the outer cover removed

which shows the position of the thermocouple, igniter and their relation to the burner


this is with the small screw removed and the burner being slid out

and this is what came out


and this is what came down the flue after seriouse scraping


My point being that all can look well but this is what lurks, it only takes a small bit of carp to dislodge and fall to partially block the burner or obstruct the T'couple or igniter, I will add that this fridge had been standing for some time like a few years without use.
mike

[Cruz]

Just lit the fridge and no flicker of the flame despite the wind trying to blow the van over.

I think the last time I had the fridge out I repositioned the lazy-t which was sitting too far down on the exhaust chimney and the chimney insulation may have been blocking the back of the lazy-t

so far so good