Glow-Worm Micron (Cast Iron) 40 FF - Sufficient 22 October 2005 at 12:19PM in LPG, Heating Oil, Solid & Other Fuels 9 replies 6.1K views

Matt83UK_2

Glow-Worm Micron (Cast Iron) 40 FF - Sufficient?

New persimmon 3 bedroom semi-detached with ensuite/mainbathroom/cloakroom etc.. has a Glow-Worm Micron (Cast Iron) 40 FF boiler in the kitchen. It looks rather small, is this sufficient?

Matt83UK_2

Glow-Worm Micron (Cast Iron) 40 FF
30/40,000 Btu's

Electronic Ignition

Height - 500mm
Width - 360mm
Depth - 262mm

Heat kW Max - 11.72
Heat kW Min - 8.79

Weight - 36.4 kg

moneysavingplumber

Check here:

http://www.est.org.uk/housingbuildings/calculators/boilersizing/

The Micron is a small looking boiler at that rating.

moneysavingplumber

The Micron 40FF has a SAP seasonal efficiency rating of 78.7% (D rated) compared to (e.g) a Vaillant Ecomax Pro 18 rated at 90.4% (A rated). If the calculator suggests it's struggling to match the heat loss requirement of the property, the efficiency will be more of a factor.

Matt83UK_2

Thanks for your help so far, much appreciated!

Here is the diagram of the house, I tried using the calculator but it came back with 12,000, could you possible give me an opinion from looking at the diagram. Cheers

It's in North west england, semi-detached, normal roof etc..
http://fxsonet.com/matt83uk/semi.gif

moneysavingplumber

It would have been 12000 watts, i.e. 41000 btus.

Your link didn't open. If it is correct then the boiler is slightly undersized. The best new ones are the modulating 'A' rated ones, the one I mentioned above modulates between 5KW and 18KW (17000 and 60000 btu) depending on the demand and has a stainless steel heat exchanger, but there are plenty of other similar ones on the market. If you are in England or Wales a replacement gas boiler has to be either 'A' or 'B' rated to comply with building regs.

https://www.boilers.org.uk

Matt83UK_2

Sorry link should work now.

I'm not able to change the boiler, it's a new build and I'm due to complete next week unforuntately.

If you are in England or Wales a replacement gas boiler has to be either 'A' or 'B' rated to comply with building regs.

It is England, "replacement", with it being a brand new build I presume this still applies?

moneysavingplumber

Matt83UK wrote:

Sorry link should work now.

I'm not able to change the boiler, it's a new build and I'm due to complete next week unforuntately.



It is England, "replacement", with it being a brand new build I presume this still applies?

It depends when it came under building control scrutiny, if before April 1st 2005 then a non-condensing boiler would have been allowed. I'd imagine that the property is extremely well-insulated and probably has a low 'carbon-index' aside from the boiler and I imagine it will work fine. Assume it is cavity insulated and the roof is insulated to the maximum and you will probably find the calculation will drop to under 40,000.

Matt83UK_2

It was signed off by NHBC and inspectors at end of July. Does it mean I can go back and tell them to stick a better one in?

moneysavingplumber

No, not if it was specified and started before April 1st 2005. The Micron is a good reliable boiler, I really wouldn't worry.