Pump flow direction

[PaulAH]

I'm getting rid of an old boiler that was plumbed to a system where the circulation pump is mounted on the return, drawing downwards. It seems that current practice places the pump on the flow side, pushing upwards.

Does anyone know
a) Why the practice has changed
b) Whether I can leave it, or would it be a good idea to switch (involving quite a lot of new pipework)

Thanks. Paul.

 

[peter anderson]

a) "The pump in the flow after the open vent pipe with the cold feed pipe also in the flow and before the vent pipe (but within 150mm).....is the best location and pipe layout for increased performance and maximium components working life"

John Reginald "Central heating"

John also says:

If you get a new pump and keep it on the return before the cold feed you can get air being drawn into the system through micro leaks in joints and fittings which speeds up corrosion.

If the new pump is after the cold feed on the return you can get water pumping out of the vent pipe which rapidly leads to severe corrosion.

I

 

[PaulAH]

Thanks, Peter. Mr Reginald would not get the Crystal hallmark for clarity but I think I see what he's saying. My old house also had the pump on the return, if I remember rightly. Maybe it's because manufacturers preferred their pumps to run as cool as possible... just a guess. Any advances?
Paul