Heat only boiler replacement question

[alankd]

Hi
I'm having a heat only boiler replacement and i just want to check if the the new one i have been quoted for is up to the job.
its replacing an old Potterton Netaheat 16/22 with a Worcester 18RI.

The question is, is the New 18kw powerful enough to replace an old boiler rated at 22kw output.

i have looked at the boiler calculator on the FAQ page that seems to come out at about 19kw, but i assume that is only a rough calculation.

The house is 4 bedrooms, bathroom + shower room total of 10 radiators. the old boiler heated the house fine until it died.

Alan.

 

[Dan Robinson]

It will be plenty - your old boiler could have been running at 16kW.

The Ri is not the best boiler though.

 

[mfarrow]

The question is, is the New 18kw powerful enough to replace an old boiler rated at 22kw output.

You've also got to take into account the assumed water temperature and size of your radiators. If your radiators are relatively small to the point where you are running the boiler pretty hot, then the new boiler will not condense enough to make changing the old one an economical solution. This can particularly be the case where you are setting your new boiler high for the purpose of heating up a hot water tank.

The Netaheats have a 68% efficiency according to Sedbuk, so the efficiency of your new boiler at your chosen flow temperature must be a lot higher than this to give you sufficient payback.

 

[dcawkwell]

Go for system boiler and sealed system.
A heat only boiler with vented system has no place in a modern heating system it's from the dark ages.

 

[Dan Robinson]

Go for system boiler and sealed system.
A heat only boiler with vented system has no place in a modern heating system it's from the dark ages.

Go on - you know you want to .

Say it...

Just say it....

 

[MJGas]

I suggest you rip the heat only out and fit a Glow worm Ultrapower 170sxi. I hear its the way foward