Boiler Upgrade Advice

[firebladerrw]

Hi,

I have a rather old floor standing Gloworm Hideaway (60,000Btu/18Kw) output boiler. Its fitted in a utility room, under a 600mm kitchen unit. I suspect its somewhere in the region of at least 17 years old !

Although it runs perfectly, this winter 2 rooms were never quite warm enough, and after checking the calculations for the room size I changed the 2 radiators to double radiators. Both rooms are much warmer now.
Downside is, I think the boiler is now struggling with the extra, and to be honest, being quite a large 4 bedroom detached house, I think the boiler's always been on the light side.

Anyway, this summer I'd like to change upgrade the boiler. Here's the rough spec:

4 bedroom house with hot water storage tank etc.
12 various sized radiators.
Circuit is pretty standard with 2 way programmer, (heating & DHW)
Existing flue is a standard square balanced flue, that will need to be changed

I'd like to upgrade to a high efficiency condensing boiler that will fit into the same space with minimum of hassle. I don't want to convert to a combi boiler. Basically I only want to change the boiler & flue.

So question is, could anyone suggest a reasonable quality free standing boiler, that will fit under a standard kitchen unit?
Intuitively, and without doing the calcs, I'd have thought a 25-30Kw high efficiency condensing boiler would be about right?

Advice on boiler anyone?

Thanks

 

[powell30]

Potterton fsb (floor standing boiler) fits into a 600mm under counter space

Can't comment on kw's required too many unknowns. I suggest you use the sedbuk calculator

 

[D_Hailsham]

I suggest you use the sedbuk calculator

Sedbuk Boiler Calculator

To avoid confusion:

All dimensions are internal
Room height is floor to ceiling
A mid terrace has 2 external walls
End terrace/semi has three external walls
Detached has 4 external walls.

 

[firebladerrw]

Thanks - 26.5 Kw from the SEDBUK calculator.

These are my choices so far:

Worcester Greenstar FS 30CDi Regular (30Kw) £1200

Potterton Promax FSB 30 HE (30Kw) £760

Ideal Mexico HE 24 (30Kw) £1200

The Potterton seems a good bet?

 

[Boilerman2]

Don't touch the Ideal Mexico (its a ICOS/ISAR in floor standing disguise) with all the same problems!!

 

[firebladerrw]

Don't touch the Ideal Mexico (its a ICOS/ISAR in floor standing disguise) with all the same problems!!

Thanks - I think the Potterton wins it !

 

[algas]

I would keep the boiler you have it will probably out live a new he boiler maybee you could zone the house & fit a higher output circulator also look to up grade system pipework & rads to convectors if they are not already.