Central Heating pump/circulator

[Winston]

I am currently proposing to do some work on my own ch, and was thinking of changing the pump. Currently got a 15/50 but was thinking of changing to 15/60 the idea being larger pump having to work not as hard would this be ok or could it cause problems also because adding a couple more rads around the house.

 

[buffy27]

this is correct and will only help with adequate water circulation.

 

[secret squirrel]

Can you put a more powerful pump in, then until you put in your new rads turn the speed of the pump down?
🙂

 

[doitmyself]

Fixed speed pumps are always a compromise. Pumps sizing depends on two factors: the flow rate and the system resistance (head).

To give an example:

Suppose the required flow rate is 0.92m³/hr (equivalent to a 12kW boiler) and the head is 3m . A 15/50 will give a flow rate of 0.94m³/hr with a head of 3.12m and use up about 262kWH per year; the 15/60 will give a flow rate of 1.02m³/hr with a head of 3.66m and use approx 331kWH.

The slightly higher flow rate just means that the temperature differential will be slightly smaller; but the higher head will mean more noise in the system and possible problems balancing the system.

The Alpha2 15/50 will provide 0.92m³/hr with a head of 3m and use about 87kWH and the Alpha2 15/60 will provide 0.92m³/hr with a head of 3m and use about 90kWH.

 

[Winston]

Cheers gents without being rude doingitmyself are you a scientist or something? 😕 I was never very good at maths! 😱

 

[doitmyself]

Cheers gents without being rude doingitmyself are you a scientist or something? 😕 I was never very good at maths! 😱

Neither, I just used the Grundfos website pump sizing calculator to do the work for me.🙂

 

[stevetheplumber]

I am currently proposing to do some work on my own ch, and was thinking of changing the pump. Currently got a 15/50 but was thinking of changing to 15/60 the idea being larger pump having to work not as hard would this be ok or could it cause problems also because adding a couple more rads around the house.

id go for the other approach seeing as its at home fit the new rads and if they dont work then change the pump chances are if its not a mansion you live in the 15/50 will be fine