cost of metal flue?

Sconsey · 14-05-2007 11:12AM #1

Hi,

I have an external boiler (in a boiler house), there's a concrete flue attached to the boiler which connects to the chimney. The concrete flue is on it's last legs (cracked all over, broken in places) and needs replacing so I am going to have the chimney flue replaced and a new boiler installed along with it. Also the chimney itself is blocked with a birds nest, lot's of dry flammible material that I can't get at to remove it.

Problem is I was intending waiting untill the summer to get the work done, but I have visitors coming next week and will need the boiler available to use, I was thinking of just getting a metal flue and connecting it to the boiler and let it exhaust out the boilerhouse door, as a temporary fix. It's a distance of about 2.5 metres from boiler to boilerhouse door. I am wondering how much a couple of lengths metal flue will cost? any ideas?

Thanks
Sconsey

eoghan.geraghty · 14-05-2007 01:27PM

Hi Sconsey,
I'm an electrician but have some knowledge of boilers as regards flues.
AFAIK, replacing a vertical flue with a flue exhausting out the door will not work or else will be very inefficient.
There is an optimum/minimum height for the flue to operate effectively, this is in order to avoid down draught and also provide sufficient draught.
One of the plumbers/heating installers who post here may be able to clarify this or correct me?
I would advise biting the bullet and get it done properly once, or at least get the chimney cleaned out in the meantime, I presume it was in use up until our balmy heatwave:)

Sconsey · 14-05-2007 05:41PM

Hey Eoghan,

Thanks for the info, some food for thought there...to be honest I can live with the inefficiency for the sake of a week or two, but the down draught you mentioned has me wondering, would there be safety concerns or are we just talking efficiency?
Thanks for any help.

Sconsey.

JamesM · 14-05-2007 05:53PM

The Concrete flue you are talking about is Asbestos :eek:
Be very careful with the dust. You are meant to dispose of it through a specialised company who will charge you a fortune

If you are talking about a very short time, you will probably get away with putting a bit of flexi-flue liner out the door.

When you change the boiler, you should use kerosene and try to put the flue straight through an outside wall, with a vent on the outside. You do not need a flue going right up to the roof. If you connect a modern boiler into the existing chimney you have, you may get damp and condensation on inside walls adjacent to the chimney - in bedrooms or on the landing etc.
Jim.

cost of metal flue?

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