Balanced Flue Gas Fire Question

[GeddyMortgage]

Hi all,

We've had a Dru Global 100 Gas fire fitted in an extension recently, we had it on for the first time properly last night (we were told to let the plaster dry on the newly made chimney breast for a few weeks before using the fire). Spec :- Dru Global 100 BF

Issue is the we had the fire set to MAX but it didn't seem to be giving off as much heat as id expected, nor did the flames seem that large either. It's a 7.5kw output (94% efficiency) so thought it'd be really warm... It's got me wondering whether it's just me or if something isn't right, so wanted to ask on here.

One thing i did think of was; I recall during the installation they had to put a couple bends in the flue to avoid a ceiling joist. Am I correct in thinking bends like this will affect the draught and therefore could be causing the fire not to run as big as it could? or totally unrelatable? Photos below. (yes that socket was eliminated )

thoughts on the above? or anything else I could consider looking into?


thanks

Ged

 

[cross thread]

Starting point would be gas pressure check / gas rate.

 

[GeddyMortgage]

Starting point would be gas pressure check / gas rate.

Thanks.

On the install sheet, that’s showing as a pass… with 20mbar.

Is it an issue that the flue has two 90’ degree bends ?

 

[cross thread]

Get the installer back to check.some fires also have restrictors depending on flue run/ length

 

[GeddyMortgage]

I’ve mentioned the low power to them once already they essentially dismissed it. So wanted a few opinions before I went back

 

[cross thread]

Ask them to gas rate it

 

[GeddyMortgage]

I’ll dig out the install sign off sheet when I get back. When they installed they checked that only a month ago.

 

[GeddyMortgage]

Sign off sheet

Also found this stuff in the manual, based on eyeballing it id say we have about 1.8-2M of vertical, 0.5M of horizontal, and 2 bends (the first being easily 1M above the unit). So I guess reassuringly puts us miles away from the non-permissible area. and lands us in Scenario A. Im wondering if the restrictor has been adjusted incorrectly.

#

 

[Harry Bloomfield]

Ask them to gas rate it

Do you have a smart gas meter? It will report the Kw consumption.

 

[GeddyMortgage]

Do you have a smart gas meter? It will report the Kw consumption.

Great shout, but alas. No. On an old U16 meter.

 

[Harry Bloomfield]

Great shout, but alas. No. On an old U16 meter.

Still doable, with patience.

 

[GeddyMortgage]

Still doable, with patience.

The northwest is a cold place. I’ll run it for a couple hrs tonight and get my calculator out it’s 7.8kw input so that should be easy to work backwards from.

 

[GeddyMortgage]

Still doable, with patience.

So ran it for 3hrs tonight, checked the meter on the hour, every hour, the fire if nothing else is consistent. But the figure has thrown another layer of confusion.

It was using, on the nose, 0.84 m3 per hour. Which would be somewhere in the region of 9.0-9.4 kw per hour. Though on the manual for the fire it states 7.8kw input, How or why should be drawing so much more than its max input?

 

[gas112]

no need to check it over hours do the gas rate in 2 mins

https://dms.niceic.com/0000003309.pdf

 

[fixitflav]

every hour, the fire if nothing else is consistent.

Don't understand that. Do you mean there is nothing else using gas during the test?
My guess is your figure is within experimental error, but at least it seems to show the gas input, and presumably heat output, meets the design.

BTW it's 9.0-9.4 kW, not kw per hour.