Pump question

[magicno1]

We have recently done some heating works where the system has been extended adding two rads. The current pump is a grunfoss 15/50-60 ups2 which worked fine before the alterations, it was new 7 months ago. Since adding a new primary loop for an extra cylinder one of the existing rads in the kitchen is intermittent. It has been fine but seems to struggle now. It is on a drop in some boxing on 15 mm hep and runs about 6 meters across a roof void and joins into 22mm direct from the boiler room which is say another 10mtrs away so should be fine.
question is can I replace the pump with a new one say a wilo pico yonus or Alpha? Will a modulating pump struggle to get it there or just go for a larger pump???? Can't get my head around the new pumps as many cant I reckon! It just needs a little more ummph

cheers

 

[missplumb]

have you calculated the size of the pump required or just guessing? The Wilo will do the job but you need to know the resistances to correctly size the pump as they use system head and that is what you set on site.

 

[magicno1]

have you calculated the size of the pump required or just guessing? The Wilo will do the job but you need to know the resistances to correctly size the pump as they use system head and that is what you set on site.

Honestly just guessing as most would!!!
how would you estimate the resistances and head is 5mtr or 6mtr?

 

[doitmyself]

the system has been extended adding two rads.

Since adding a new primary loop for an extra cylinder one of the existing rads in the kitchen is intermittent.
cheers

The current pump is a grunfoss 15/50-60 ups2 which worked fine before the alterations.

Is the extra cylinder controlled by a motorized valve?

If so, is the kitchen rad OK when the MV is closed, i.e when the new cylinder is not being heated.

If it is, then it may be a case of balancing the cylinder so it does not grab more than its fair share of the flow. The should be a gate valve on the return which can be used for this.

Is HW separately timed so it does not come on when central heating is most required, i.e. first thing in the morning?

PS Was the heating system re-balanced after the additional rads were installed?

 

[magicno1]

Is the extra cylinder controlled by a motorized valve?

If so, is the kitchen rad OK when the MV is closed, i.e when the new cylinder is not being heated.

If it is, then it may be a case of balancing the cylinder so it does not grab more than its fair share of the flow. The should be a gate valve on the return which can be used for this.

Is HW separately timed so it does not come on when central heating is most required, i.e. first thing in the morning?

PS Was the heating system re-balanced after the additional rads were installed?

Correct it stops when the cylinder is heating. It has a zone valve.
think you are right in saying the system needs balancing correctly. Got to go this week so I'll spend some time with it cheers!

 

[magicno1]

In simpleton terms.... How do you calculate head as in 5/6 mtr?

 

[missplumb]

distance between your highest and lowest points.

 

[doitmyself]

distance between your highest and lowest points.

Oh dear!

It's nothing to do with the actual height and certainly not the distance between highest and lowest points.

The head is the pressure loss round the system due to friction.

This confusion would disappear overnight if the industry stopped using metres (of water) and instead used Bar or kPa (kiloPascals) to measure the pressure loss in heating circuits.

 

[AWheating]

You want to calculate the index circuit ( the radiator/ circuit with the most resistance)

Either time the hot water before the heating comes on so once the heatings on the hot water is satisfied and off. Or fit a balancing valve on the cylinders return , like a 22mm lock shield gate valve.

also check the auto bypass is set correctly.