what speed to put my central heating pump on?

Andy From Sligo

I have just measured from the last radiator on the circuit and its at a crazy 60ft away from our central heating pump (well it surprised me, I knew it was far away but didnt think it was that much) - its a bungalow and the Central Heating Pump (grundfoss) has 3 speeds on it and im wondering what the best speed (1,2,3) is best to select on the pump (it was on 2 when we moved in) but with such a large circuit and the last rad being 60ft away im wondering if I should put it on 3? - the last radiator takes an age to even get warm. The pump is on the return pipe to the stanley 80K brandon range oil boiler by the way if that has any bearing on anything. Thanks.

Firewalkwithme

I have a custom made Grunsfoss pump.

It goes up to 11.

Andy From Sligo

also does anyone know why the pump is on the return pipework on this heating system and not on the flow like other boilers are?

shedweller

Andy From Sligo wrote: »

also does anyone know why the pump is on the return pipework on this heating system and not on the flow like other boilers are?

My take on it is that the return is cooler and therefore more dense and is more efficient to pump. Also easier on the pump.

deandean

It's not the length of your pipe, it's the amount of head that's important.

:pac:

In a bungalow you're only pumping vertically a few metres so I'd say the lowest speed is fine. Try it. It'll use less energy, and be quieter.

Andy From Sligo

deandean wrote: »

It's not the length of your pipe, it's the amount of head that's important.

:pac:

In a bungalow you're only pumping vertically a few metres so I'd say the lowest speed is fine. Try it. It'll use less energy, and be quieter.

thanks for that, so you reckon i might be able to get away with speed 1 on the pump then and it shouldnt overheat boiler or anything and still push to the furthest rad 60ft away you reckon? - if so, I will give it a go

Andy From Sligo

im predicting the last radiators on the circuit are taking ages to warm up because all the other radiators before it need balancing up properly? - I have noticed that both valves on all radiators before it are fully open

deandean

Andy From Sligo wrote: »

im predicting the last radiators on the circuit are taking ages to warm up because all the other radiators before it need balancing up properly? - I have noticed that both valves on all radiators before it are fully open

Yea your system will need balancing. On the rads closest to my boiler I ended up closing the balancing valve completely, then opening it only 1/4 or 1/2 turn; whereas the furthest-away rad has the balancing valve fully open.