information needed on replacement boiler

[wigglyworm]

hi new to this forum.
we live in a two bed 1984 house and have an old thorn Apollo boiler in the kitchen.the hot water tank is in the airing cupboard in the main bedroom.
eventually we will have to replace this boiler so i am gathering info at the moment.what i would like to know is a normal condensing boiler cheaper to fit than a condensing combi boiler bearing in mind we have all the radiators and water tank in place.if a combi is cheaper as a boiler would a install in the airing cupboard be easier.the gas meter is on the same external wall as the airing cupboard in the bedroom so supply would not be a problem.the only problem i can see would be the condensate pipe drainage,we share guttering which drains next door so i would not know where it could go.if we had a new boiler in the kitchen we still would need a gas supply to it as i think the old one is 15mm and new regs say it has to be 22m is that right?
so to sum it up what would be the cheaper option and what would be the best location.this is our first house so sometime in the future we would be moving so do not want to spend a lot at this time.
sorry about the long thread i probably will have a lot more questions to ask.thanks in advance.

 

[chrishutt]

A Combi boiler would be more expensive to install for several reasons. Firstly it will need a new gas supply whereas a system boiler might be able to use the existing gas supply. Secondly the Combi will require new hot and cold pipework to be run to it, plus the removal of the existing hot water cylinder, feed tanks and associated pipework. Furthermore if the Combi were to be in the airing cupboard the flueing (vertical?) might be a lot more expensive.

However you must consider whether a Combi will be advantageous in terms of improved hot water pressure (better showers) and freeing of space currently occupied by cylinders and tanks. However with a Combi when the boiler breaks down you lose hot water as well as heating, whereas a hot water cylinder can be heated via an immersion heater.

 

[EliteHeat]

would like to know is a normal condensing boiler cheaper to fit than a condensing combi boiler bearing in mind we have all the radiators and water tank in place

Usually, but not always

if we had a new boiler in the kitchen we still would need a gas supply to it as i think the old one is 15mm and new regs say it has to be 22m is that right?

There are no new regs

so sometime in the future we would be moving so do not want to spend a lot at this time

You will be spending a lot of money, regardless of what option you choose.

 

[weareleeds]

Before deciding which way to go thoroughly check condition of cylinder for leaks especially where the flow & return connections are as changing this would add extra cost

 

[wigglyworm]

thanks for your replys, i forgot to mention the system is microbore would there also be a problem with radiators leaking due to hi pressure from a combi. one more thing if i kept the boiler in the kitchen could i still use the same gas supply if its 15mm or does it now have to be 22mm.
i think i would go with a normal condensing boiler in the same place as the old one.the more i think about things the more questions i have hope you don't mind.are these condensing boilers sealed units that vent outside, if so could i conceal it in a cabinet. thanks again for your help.

 

[chrishutt]

Only a competent gas installer can tell whether your existing gas pipe is adequate for the existing boiler or a new boiler. The pipe doesn't have to be 22mm, which you've been told already. It has to be adequate to deliver the required volume of gas with an acceptable pressure drop (0.1 mbar). So it depends on the output of the boiler and the distance from gas meter to boiler.

Microbore need not be a problem, nor would the increased pressure of a sealed system necessarily be a problem, but it may be that the radiator valves are leaky anyway and will need replacing.