What Boiler Should I Choose?

[Scott G]

Hi All, I have recently bought a 1930's 3 bed semi and am in the process of renovating. I currently have a back bolier in a fire place with a lovely (?) old fire type thing as it's customer facing end! It feeds approx 6 rads and a tank. We want to get rid of the fire and accept that a new boiler is probably our best option. So should I go for a combi or a convential boiler? A few points to consider:

1. I would like the new boiler to go in the outhouse which is behind the kitchen
2. The old boiler will need to be taken out
3. I dont care about 'instant' hot water
4. I would like the most reliable solution
5. I would also like the most simple solution (in terms of plumbing effort)
6. I will be getting a plumber in to do the work

Any help would be appreciated as I know nothing about plumbing and boilers! Scott (Kent)

[IMM]

How many baths, showers, etc. Is the house big? Is the water main good enough in pressure and flow? Is it short of space, etc. Is the outhouse well insulated and does the door have a good seal, etc.

A good simple solution is a "square" 150 litre DHW only thermal store with immersion backup, giving mains pressure hot water, at the top of the outhouse and a system boiler under. Well packaged saving space see:

Elson Coral ST thermal store. All Elson "Coral" products are square thermal stores that can be easily packaged in high positions or under worktops. They have about 3 variations.

A system boiler? Well any good make like Vaillant or the Ideal ICOS condensing boiler is worth going for. Or, the Ideal Isar, the same boiler but the combi variant, is the same price as the ICOS from

So it may be worth using the combi as a normal system boiler, heating the thermal store and the heating directly, and connecting up the water section. Have two full bore valves on the draw-offs off the thermal store and a combi, and just turn one off and one on to get the combi to supply the hot water. Simple. Normally you will on the thermals store. Another backup mechanism for free. This method is well worth considering, and one I would probably go for. Well until you tell us the other points of course.

[IMM]

URL did not work. It does now.

How many baths, showers, etc. Is the house big? Is the water main good enough in pressure and flow? Is it short of space, etc. Is the outhouse well insulated and does the door have a good seal, etc.

A good simple solution is a "square" 150 litre DHW only thermal store with immersion backup, giving mains pressure hot water, at the top of the outhouse and a system boiler under. Well packaged saving space see:

also: to products.

The Elson Coral ST thermal store. All Elson "Coral" products are square thermal stores that can be easily packaged in high positions or under worktops. They have about 3 variations.

A system boiler? Well any good make like Vaillant or the Ideal ICOS condensing boiler is worth going for. Or, the Ideal Isar, the same boiler but the combi variant, is the same price as the ICOS from

So it may be worth using the combi as a normal system boiler, heating the thermal store and the heating directly, and connecting up the water section. Have two full bore valves on the draw-offs off the thermal store and a combi, and just turn one off and one on to get the combi to supply the hot water. Simple. Normally you will on the thermals store. Another backup mechanism for free. This method is well worth considering, and one I would probably go for. Well until you tell us the other points of course.

[Roger Mills]

It may depend to some extent on whether your existing system is fully pumped, or whether it has a gravity hot water circuit.

If it's fully pumped, there may well be a single pair of flow and return pipes from the boiler to the airing cupboard - which houses the pump and a

3-port (or 2 x 2-port) valves to split the HW and CH circuits.

If yours is like this, you can leave the vast majority of it in place, simply running new flow and return pipes from the new (conventional) boiler location to the airing cupboard.

If it isn't like this, it gets a bit more complicated - and we would need a description of the current setup in order to comment further.

Roger

[Mark S.]

You can take the old boiler out yourself but it's messy work. ;-) The best sort. :-)

S.

[Scott G]

Thanks you for all your comments. I will try and get you a more comprehensive overview of my current system to aid the discussion. But as far as I know the current system uses a gravity feed for the hot water, whereas the cold pressure seems quite good.

There are about 5 pipies in total going from the boiler downstairs, up to the airing cupboard.....this isn't much help is it! I will find out exactly what I have..!

As for the 'outhouse' it's actually an outside toilet at the moment, so it has no insulation although I am planning on outting a new 'sealed' door on it.

Scott

[Keithc666767117]

Scott, When choosing boiler consider your heating and hot water requirements...If large consumption consider conventional boiler,However if you have a smaller consumption go for a combi to answer your question on the simpliest option this will be a combi as very easy to install. Position boiler and rads,then run copper. Mains feed in domestic hot out Heating flow out and heating return in and finally you have your gas connection.Have a look at plumbworld.com quite useful