Replacing a standard boiler with a combi - a good idea?

[fatty]

Thanks for all the replies folks. Just to compare, what is a typical flow rate from a cylindr mounted on the same floor as the bath? Is it about 15-20 l/min?

With combis, what is the limiting factor to its hot water provision, the temperature of the input water or the pressure in the combi system?

How does a combi work anyway? Does it take in cold water from the mains, heat it directly and then pump it around the house? Are the CH and HW separate i.e. if you have the CH on does that make any difference to the rate and temp at which HW is supplied?

Thanks again.

P.S. as for me being competent, I can use a spanner and can take radiators off, but I would have no intention of messing around with gas appliances. That's for the experts and the idiots.

 

[tryitandsee]

I let a few one bedroomed self contained flats, all having different combi boiler 'set ups'. Ranging from Bittony wall hung water heaters to Worchester greenstar condensing combi's. They all have their various good and bad points, but I would never recommend a combination boiler to have in your own home. The main reason being, you can't 'dribble' the hot tap into the bath to keep it hot as you drift off to sleep. You try doing that with a combi.
In my own home I have not taken the cover off the Gloworm fuel saver since I moved in, some 10 years ago. Yet the flats cause me so much grief. Combi's need nurturing, they need to be understood, there are to many working parts and complicated sequences to follow. Which, in my humble opinion, means trouble.
Keep it simple, combi's aren't.

 

[Water Systems]

I let a few one bedroomed self contained flats, all having different combi boiler 'set ups'. Ranging from Bittony wall hung water heaters to Worchester greenstar condensing combi's. They all have their various good and bad points, but I would never recommend a combination boiler to have in your own home. The main reason being, you can't 'dribble' the hot tap into the bath to keep it hot as you drift off to sleep. You try doing that with a combi.

Depends on the model.

In my own home I have not taken the cover off the Gloworm fuel saver since I moved in, some 10 years ago. Yet the flats cause me so much grief. Combi's need nurturing, they need to be understood, there are to many working parts and complicated sequences to follow. Which, in my humble opinion, means trouble.
Keep it simple, combi's aren't.

Modern system boilers are not much less complex than a combi.

With combis, and other boilers types for that matter, generally the more expensive the less trouble.

Combis "systems" are gernerally not more trouble than an tank/cyldiner 3-way valve setup. With a combi the system is in the box. If a mid-position valve has a problem in a cylinder setup no one ever blames the boiler. Take into account all the problems with other "systems", inc the F&E tank, cold water tank and cylinder, and there is not much in it.