Why range rate a modulating boiler?

[Madrab]

A lot of boiler noise comes from the fan ramping up under full load/ouput

Range rating a boiler down is usually achieved by winding down the fan settings (RPM), it may not actually say that on the adjustment setting but that is in effect what it would be doing. Therefore the boiler may not sound like a jumbo taking off when it starts up, which I presume is what you hear being up above it in the bedroom.

 

[JohnOfChelmsford]

@mrbg07546 It's stated as an "Integral, variable speed high efficiency circulation pump". Documentation is a bit vague as it initially only mentions it's variable based on "Outside temp" so you could read that as only when using Weather comp. But there is a section to describe how you change max in 'standard mode'. There's no auto - just a 1 to100 option for the max speed.

 

[mrbg07546]

Ok basically that’s the same as working out pump speed based on return temp. so you may not need to touch it

 

[JohnOfChelmsford]

A lot of boiler noise comes from the fan ramping up under full load/ouput

Range rating a boiler down is usually achieved by winding down the fan settings (RPM), it may not actually say that on the adjustment setting but that is in effect what it would be doing. Therefore the boiler may not sound like a jumbo taking off when it starts up, which I presume is what you hear being up above it in the bedroom.

that would be great if the case. I'll just have to give it a whirl and see. Would be nice if the boiler had explicit control for this or even a 'soft start' option which would heat slower but quieter.

 

[mrbg07546]

The advantage of lower range rating is less massive spikes in tempreture, and more eco as it is in lower flow temps longer as it is getting to temp. As a example it’s -2 today and my boiler takes 1 hour to get up to 45 degrees. Once it’s their it stays .