Central Heating Pump

[Jimmy_shy]

I am about to de-commission and old (mixed origin!) gravity fed central heating system, but before I do I'm just confirming my understanding of how it all works. The boiler is a Potterton Prima C and I've traced all the flows and returns, and everything seems consisent with 'text book' illustrations and the boiler installation instructions, save for one anomaly. The sole pump seems to be on the return pipe just before the boiler/cylinder Tee joint on the boiler return valve. All the stuff I've read shows the pump on the flow pipe to the expansion/top up/radiators and top cylinder. I did see one illustration that shows the pump in my position as an 'alternative position'.

Is this correct? Any help would be much appreciated!

 

[kevplumb]

used to be common practice the theorey ranged from the pump runs cooler to keeping the system under negative pressure stops leaks

neither of which makes much difference as your new system will have to be fully pumped to comply with part l the pump will have to go on the flow

 

[Jimmy_shy]