Mum trying to buy the right output boiler...please help!

[mitcheso]

Hi there

I am in need of a new regular boiler. I have a friend who is a plumber and suggested (without any calculation or questions relating to insulation etc) that I would need to buy a 30w output boiler. However I have followed the link on this site to a output calculator and made all the necessary measurements etc and the result was that we will require a 10w output. This is somewhat different to what our plumberfriend said and I am concerned that I do not want to buy a boiler that has more power than needed as I believe this is not a good idea.

I live in a square shaped reasonably sized 4 bed detatched, bathroom, en suite with shower and downstairs toilet. Full UPVC double glazed, recently cavity wall insulated and Loft insulated with pitched roof.

Please can anyone advise .....

Thank you

 

[mickyg]

that sort of house i would guess at about 14-18kw. 10 sounds a bit low tbh. but 30 is total overkill. Unless your replacing radiators then the radiators will dictate how much heat you can put around the system, so you can use them as a guide

 

[mitcheso]

Thank you for your reply

we have 9 rads (2 of which are double) and 2 towel rads in total

 

[gas4you]

that sort of house i would guess at about 14-18kw. 10 sounds a bit low tbh. but 30 is total overkill. Unless your replacing radiators then the radiators will dictate how much heat you can put around the system, so you can use them as a guide

I would agree with the above. I doubt more than 18Kw will be needed.

Ask him to quote for an 18Kw boiler, a system boiler prefereably.

 

[yerino]

Have you thought whether in the future you might want to add more radiators to the system or extend the house? .. If so maybe best to go for a 24kw. If not 18kw should be more than enough.

 

[mitcheso]

The only thing we may possibly add would be a conservatory in the future and so one additional rad at some point.

Also can I ask what is the difference between a system boiler and a regular boiler? and can you recommend any?

 

[mickyg]

Thank you for your reply

we have 9 rads (2 of which are double) and 2 towel rads in total

probably no more than about 13-14kw then. tbh its the installers job to size the boiler correctly and if someone is saying 30kw then they may not be the man for the job. If they dont know something so basic, what else dont they know?

 

[macfudd]

A system boiler and a regular boiler are the same thing.Not to be confused with a combi(combination) boiler.

As for recommending one,I wouldn`t dream of stepping on the toes of the many installers here who have many and various different opinions.But I have always installed Worcester Bosch and had very few problems with them over the years.

 

[kevplumb]

A system boiler and a regular boiler are the same thing.Not to be confused with a combi(combination) boiler.

As for recommending one,I wouldn`t dream of stepping on the toes of the many installers here who have many and various different opinions.But I have always installed Worcester Bosch and had very few problems with them over the years.

err

mc bo llocks no they aint

reg boiler is just that
system boiler has the pump ex vessel prv etc built in

 

[Agile]

You mentioned a "plumber" ! Thats someone who fits bathrooms and drainage.

It sounds as if he has no idea of what power boiler is required or how to calculate it.

It could quite easily only need 10kW but see what a few different programs give. Depending on the program you might have to add 2 kW for heating the cylinder.

I agree a 13kW boiler would probably be adequate but as a little oversizing is not too important at the lower end then an 18 kW would not be a problem but a 30 kW would be!

Tony

 

[D_Hailsham]

I live in a square shaped reasonably sized 4 bed detatched, bathroom, en suite with shower and downstairs toilet. Full UPVC double glazed, recently cavity wall insulated and Loft insulated with pitched roof.

In that case the 10kW (not 10W!) is much nearer the mark than the 30kW quoted by the installer - unless he was thinking of a combi boiler.

It might be worthwhile installing something slightly larger than 10kW, say 15kW, to allow for any proposed extensions and even for lower winter temperatures; as most calculators assume an worst case of -1C outside.

Most installers only consider the max output of a boiler. But the minimum is just as important as the boiler will spend most of its time at the lower end of the range. So, if you need 10kW, a boiler which gives 6kW to 18kW will be more efficient than one which gives 9kW to 27kW.

 

[yerino]

A system boiler and a regular boiler are the same thing.Not to be confused with a combi(combination) boiler.

LOL at this comment!

My advice is to get a GASSAFE engineer around to size up for your new boiler correctly.

 

[D_Hailsham]

My advice is to get a GASSAFE engineer around to size up for your new boiler correctly.

And how would you go about sizing up a boiler?

 

[ServiceNumpty]

For my tuppence worth I reckon her plumber friend has sized a 30kw combi, not heat only.

 

[Agile]

And how would you go about sizing up a boiler?

You walk around it sucking air in through your teeth!