Combi Boiler Choice, please help!

[Andy]

Hi,

Just when I thought I was ready to purchase my Combi Boiler, I remembered the flue!

My boiler will be sited just over 5m from the nearest suitable outside wall, vertical flueing is not an option, so it has to be horizontal.

I can't find a boiler to suit my needs.

The boiler spec is:

Natural Gas Combi Boiler

5m+ flue length (prefer single coaxial flue) Will only need to run 4 radiators Needs to be able to run a multi head shower

Can you please help me find a boiler to fit the above spec, and a Mail Order supplier for it?

Many thanks.

-- Andy

[Ed Sirett]

ISTR that one of the Ideal model s can have a substantial flue length.

You may find that you can have the length you require if you up the size from 100/60 to 125/80 concentric flues.

Some manufacturers offer an adaptor to go to 50mm (nominal c. 56mm OD) plastic pipe this might only be for condensing models.

The bottom line is that flue planning is an itegral part of boiler selection which in turn is only part of the choice of components for a heating system.

HTH

[Simon Stroud]

We have their EC31S combi with a long (approx 4m) flue.

It can handle far longer than that and the flue is a plastic pipe.

It's a fully modulating condensing combi. Being fully modulating, it lowers its output to remain in condensing mode even under low demand, so the flue temperature is always low. Hence the plastic flue. I think for most combi installations you would be looking at a rather high boiler capacity (in our case 36kW) to suit the hot water requirements, and this is typically much higher than what is needed for the heating side of things.

They do a slightly bigger one (EC38S) with a 46kW hot water capacity. They modulate down to a very low level when required (4.5kW for our one, 6kW for the bigger model) so fine for a wide range of heating requirements.

Not cheap though.

Regards, Simon.

[IMM]

But very, very, good. You get what you pay for.

[Seri]

outside

The Worcester-Bosch condensing combis can have an 'equivalent' horizontal max flue length of up to 13m, the top end models only have an 'equivalent' max flue lenght of 10m, but that's still likely to be more than adequate.

It's worth remembering though that each 90 degree albow bend that you use counts as 2m.

just quickly, models: R25HE R30HE have a max horizontal flue length of 13m

and models: R35HE+ R40HE+ have a max horizontal flue lenght of 10m

All of the above boilers are SEDBUK Band A efficiency, they're not overly cheap though.

Hope this helps

Seri

[Seri]

horizontal.

I forgot, when I was purchasing my boiler I found Discount Central Heating Supplies

to be the cheapest, had great service from them too.

[John Rumm]

I am sure there are others that would fit your requirements but here are two that can have horizontal flues up to 6m long (the HE35 will only support a 3m flue):-

sure how cheap the above site is - I bought the HE35 from our local vilage shop for about 130 less than show on the web site!)

To find others, just download the instalation/service manuals from the makers web sites - they will list the maximum flue lenghts.

[David]

In article , IMM writes

Its nice that you finally agree with the rest of us, now apply this to power tools and you will be getting there

[IMM]

I am agreeing with one man not you.

Different products with different usage and importance. I seems you can't out something so simple.