Flu liner advice please for an Oil fired boiler

[tobybuk]

Having been told that my old WallFlame type oil boiler was likely to catch fire I've decided to get a new boiler installed. I guess 25 years service isn't too bad?

The boiler is actually located inside the garage in a sectioned off partition that is only accessible from the outside of the property.

The current boiler has a vertical flue that goes straight up and exits 2/3 from the top of the roof (exits vertically). It looks in good condition and seems to be about 8" wide (I can measure exactly if required but I guess it wouldn't change the principle of any advice given?).

I've select a Grant EuroFlame BoilerHouse 70/90 as the new boiler.

My question is what should I do about the flue? Since the current Flue seems in fairly good condition, is it normal to have a flue liner fitted and reuse it for the new boiler? If this isn't the best way to go, what do you recommend? Any tips/pointers on what I should have done would be very welcome.

Thanks

Toby

 

[Slugbabydotcom]

My question is what should I do about the flu?

I suggest that you see your doctor about a flu jab!!!

 

[oilman]

You should fit a 4" liner as the liner usually has a life of 20 years but is much too big in this case anyway. I have seen a liner which was sitting on the top of a flue section that went as far as the chimney, so a top fixing had been dispensed with. This meant the liner could be pushed up from the bottom. Not "good" but it did the job.

Why is your wallflame boiler going to catch fire? Sounds like a ploy to get a boiler change job. There is the problem of spares, like "there aren't any".

 

[tobybuk]

Thanks for the reply.

I booked a service; I could smell fuel when the boiler was on. The engineer spent a good while looking at it and said it was probably best to install a new one rather that patch the old one up. He had nothing to gain really as he doesn’t do installs and didn't offer a suggestion as to who I should use. I could patch the old one up but I’ve never really been happy with it (gravity system, Thermo installed in a cold hallway etc). So I decided to bite the bullet and install a new one.

I guess a liner would have to go the full length of the old flue? Is it OK for it to ‘flop’ around inside the old Flue or does it have to be packed in there? I want to know what to expect so I can ensure that the guys I get to do it don’t ‘bodge’ it.

Thanks again for the reply.

 

[oilman]

I would just thread a liner inside the old one, but get it swept first, then leave it floppy. You will need a rigid flue section to reach the chimney, as liners must be enclosed.

 

[PaulAH]

Oh sh-1-t. Does this mean you have to have a solid pipe from the boiler up to the chimney base, in my case about 4ft?. Even if it's all enclosed in a cupboard? (Haven't started the job yet).

 

[oilman]

Yes, and (heh! heh!) if it's a single wall flue in the cupboard, you need to keep it 25mm away from everything, though you could surround it with plasterboard, or use twin wall, gosh the possibilities are endless. But, simplest and easiest is just to get a piece of flue pipe, unfortunate that the longest section is usually 1m. This will cost about £40, but you might pick up a used bit from somewhere, could be cast iron for example.

Incidentally, what is the air setting on your burner?
I may be able to put you in touch with an oil outfit (oftec reg) which would get back to you. Email if you're interested.

 

[PaulAH]

You're a rotten swine and you're not coming to my birthday party.

A while back, I asked if anyone would like a superb, solid, enamelled cast iron flue. Advice was to skip it. Guess where this magnificent piece of ironmongery came from - the very place where I now need a superb, solid...

25mm not a problem. I take it that the spirit of the law is protection against physical damage (although when did "spirit" ever come into these regulations?). Plasterboard may be the answer. You know how I like to do things properly, even if it doesn't involve Adrian from the council.

What is the air setting on my burner? What is "the air setting on my burner"?

May well contact you re reliable OFTEC person. Usual address - [email protected]?

 

[oilman]

I'm too far away to come to your party.

On your burner, which is a Riello RDB there is a red plastic cover, and to the right of that is a window with a scale showing, and near it is a hole for a 3mm allen key, what is the reading on the scale?

You could have found this from the burner leaflet in your boiler data pack of course

Email addr is in my profile, or try here, smartie.

 

[PaulAH]

Oh great. Now you're asking me to find a torch that works.

Dunnit. 6.

Email addr is in my profile

Boring. Thought you lived on the moon. Your other address, very useful: "What can you do to protect yourself and your family from terrorism"

 

[oilman]

...............

Dunnit 6.

..................

6? 6? No wonder your exhayst gas smells

 

[PaulAH]

Come on then. Don't keep us in suspense.

 

[PaulAH]

One more question if I may (well, five questions).

1. Been looking at the OFTEC guide and Building Regs Part J. They contradict eachother. OFTEC says a liner, when fitted within an existing chimney, should be packed with insulating material. Two Jags says just the opposite - air space is adequate. Any observations?

2. The Boulter conversion kit I've bought allows the liner to be taken straight to the boiler, using an adaptor that bolts onto the outlet. How does Mr Sweep do his stuff? Unbolt from boiler?

3. Part J says there shouldn't be bends in the liner. Unfortunately my boiler is offset from the stack base by about 18ins to the right (total length of run about 4ft). But a solid pipe with sharp bends is surely going to offer more resistance to exhaust flow than a gentle sweep of liner. What's the problem?

4. So it seems I can bring the liner to the boiler but only if it's straight. Huh. That aside, I've got to shield the liner where it's exposed between the stack base and the boiler, right? Would a plasterboard casing definitely be OK? What about a wooden frame - is that acceptable?

5. (Back a step). What's wrong with air setting 6? It was factory set. Too rich or lean? No, I don't intend to tamper unless you suggest otherwise.

 

[oilman]

1) airspace is ok except for vapourising burners with chimney on the outside wall.

2)Don't think it should go straight to the boiler, Better to have a stiff bit and an access door in it.

3) Theorectcally 2 bends allowed of 45 deg.

4) See 2.

5) Miles too lean so that lazy installers who just fit and **** off don't leave it to soot up. If you have a way of seeing if the boiler is making smoke, then you can wind the air down till it just smokes, then back it off a bit. Don't try to do it by looking at the exhaust for smoke, there's so little you'll never see it. If you can see it, .........why don't you listen, did I just tell you not to look?

 

[PaulAH]

Pragmatic as ever. Thanks, Oilman.

Better to have a stiff bit and an access door in it

All the way to stack base or enough to accommodate Mr Sweep? I know you're going to say the former but it seems a waste to throw away a stretch of liner I've just bought and replace with expensive pipe.

then back it off a bit

Reduce from 6?

Miles too lean so that lazy installers...

Who you calling lazy?