Boiler Minimum Flow Rate

[cocjh1]

I'm trying to find out the minimum flow rate (in litres/min) for my Ideal Classic FF 60 boiler:
http://idealboilers.com/installer/wp-content/uploads/sites/2/2013/08/156647_1.pdf

Can anyone point me to the correct part of the manual please? I can't find any reference to a suitable figure..

 

[picasso]

Depends on what output your boiler has been set at, here is the figure for the highest output.

 

[Dan Robinson]

Nowt like rtfm

 

[cocjh1]

Yeah rtfm! I did that and it wasn't obvious to me..

But I did read that table as the required flow rate when burner is lit.

What about minimum flow rate to protect against overheat, when the burner is off?

Basically, I'm trying to size a suitable TacoSetter inline valve..

 

[picasso]

The tacosetter is the wrong valve, you need a bypass valve like the Honeywell du145.

 

[Phill Peck]

The tacosetter is the wrong valve, you need a bypass valve like the Honeywell du145.

Maybe he wants a British gas bypass

 

[picasso]

I wondered if you would pop up.

 

[cocjh1]

I don't want an ABV as pump is going to be a variable speed variety.

Either way, is 22.8 l/min the minimum flow to avoid overheat when not calling for heat?

 

[picasso]

Do not put a variable speed pump on a fixed output boiler, if you want to stop it over heating when the zone valves shut put in an automatic bypass,

or do want you want as you don't seem to take advice to well.

 

[cocjh1]

Ok, so what's your issue with variable speed pumps and fixed output boilers?

 

[picasso]

They are not compatable.

 

[cocjh1]

Really. Through your experience I guess?

 

[picasso]

Your boiler has a fixed output of around 17kw, so it needs 23 litres per minute running through it to stop it overheating, you want to stick a variable speed pump that could go considerably lower than this, what do you think will happen ?

 

[Phill Peck]

Your boiler has a fixed output of around 17kw, so it needs 23 litres per minute running through it to stop it overheating, you want to stick a variable speed pump that could go considerably lower than this, what do you think will happen ?

Ow ow I know I know pick me

 

[Phill Peck]

Can we go back a few steps and ask why you want a variable speed pump?