Replacing chimney pot

[Mary Fisher]

One of the original four chimney pots was dislodged when the Earth moved and now leans a little. We have to something about it sooner rather than later and don't know whether it will be better to re-seat the old one or replace it with a stainless steel 'thing' which a few neighbours have used.

I prefer the former option.

a) are there efficiency advantages in replacing it with something else?

b) what are the stainless steel 'things' called?

c) do we need to consider anything else?

Getting up and doing the job is no problem.

Mary

[dom]

Is the chimney in use? For solid fuel, oil or gas? Is there a liner inside the chimney? Does the liner terminate at the bottom of the pot or at the top? Do you ever have problems with backdraughts?

The stainless steel thing is called a terminal. Be aware that building regs has quite a lot to say on the subject.

[Andy Burns]

cowls?

[Mary Fisher]

Yes.

Gas.

We intend inserting one when we do the chimney.

No. Nor damp.

Yes, I've just Googled and discovered that - it took some finding though so if I hadn't I'd have been grateful :-)

Where can we find them?

Mary

[Mary Fisher]

Thanks, but no. They're terminals apparently :-)

Obvious, really ...

Mary

[Andy Burns]

What's the difference, more than just terminology?

Image searches for "flue terminal" and "flue cowl" bring up objects that look the same to me.

[Mary Fisher]

Was that deliberate? I like it anyway!

But don't know the answer.

I believe that cowls are designed to keep out weather in some way, they're usually directional or mobile. I think.

But terminals just sit there, terminally :-)

Mary

[dom]

Fan assisted like a boiler or convection like a gas fire?

Ah - it might be a terminal when it's balanced flue (which your isn't), and cowl when it isn't.

Lots of good info here:

> Be aware that building

Here:

extensive reading

[Mary Fisher]

Convection.

Very useful, thanks a million. I'll peruse both later.

Mary

[The Natural Philosopher]

Cowls I assuem. Handy to stop smoke and birds coming down the wrong way.

Not in respect of the pot, no. ;-)

[Andy Burns]

Actually no, I was just trying to make it clear I wasn't bing sarkie.

Several (but not all) of those that come us as a cowl *do* either spin round and round, or rotate to face downwind, but various definitions I've just seem to say they're for increasing draught, or preventing back draught, not that spinning is necessary.

[tinnews]

Is there a right way for birds?

[Mary Fisher]

I wondered that ...

However, panic over. He's just been on the roof and found that the flaunching is sound and the pots immovable. The one which looks as though it's at a different angle must always have been like that :-)

Or my eyes have deteriorated in the last few weeks ... :-(

Anyway, I've learned a lot and am grateful for everyone's input.

Mary

[Ed Sirett]

[e-mail]...

In this case the regs to comply with are the gas appliance instructions and/or BS 5440 (which have been made available for file sharing).

The flashy stainless rotating units are non-approved for use with a gas appliance IIRC.

If your gas fire is a functional rather than decorative unit then its efficiency is about 75% and altering the flue will make little difference (although some will make it potentially dangerous).

If your gas fire is a decorative unit then the most efficient setting is OFF, and likewise the flue is either compliant or not and not might be a "Bad Thing".

[Mary Fisher]

...

We weren't thinking of a flashy rotating one - not our style.

The intention of inserting a liner was because we keep being told that it was a legal requirement. We wouldn't do it unless we had to do other work and we don't now.

A decorative gas fire??? That's not our style either :-)

Before anyone tells me what we should do in the way of room heating I'll explain that our dining and sitting rooms are only heated occasionally. The best way, we've found, is to us the gas fires (Gas Misers). We don't spend much time in those rooms, only for meals in one and very occasionally entertaining in the other. When there are other people there's rarely a need for other heating, our house is well insulated and warm.

Mary

[Ed Sirett]

good, just make sure the new one complies with BS 5440.

For a general purpose flue, yes, for a gas appliance it will depend on what the manufacturers (of the gas miser) require.

OK.

Exactly, which is less 7kW to heat a room or 18kW to heat the whole house!

[Mary Fisher]

The whole house is rarely heated. The ch thermostat is set at ten and the timer for 7.30 - 8.30 am. The boiler fires up only when it's VERY cold.

Most of the time we're moving around, when we're sitting (only for a short time and not every evening - no telly you see) we sometimes like a bit of extra warmth - from the fire.

We think our system is right - for us. Our gas bills seem to support that opinion.

Mary