pump still running.should it?

[ohmygodwhathaveyoudone]

have drained my central heating system by tying up the ballcock in the small header tank in my loft and drained all the radiators,have also turned of the room thermostat and the boiler programme for no central heating.the system is not a sealed and i do not have a combi boiler.
the problem is the pump started this morning with no water in it,a loud clanking sound it made and the only way to make it stop was to turn off the hot water on the boiler programme ?could it be the bypass valve or something?any advice would greatly appreciated.thanks.

 

[EliteHeat]

The pump is supposed to run for both central heating and hot water since you have a fully pumped system.

It sounds like you have bollixed the pump by allowing it to run dry, so this will have to be replaced.

 

[meldrew's_mate]

have drained my central heating system by tying up the ballcock in the small header tank in my loft and drained all the radiators,have also turned of the room thermostat and the boiler programme for no central heating....

I assume the system is still drained.

the problem is the pump started this morning with no water in it,a loud clanking sound it made and the only way to make it stop was to turn off the hot water on the boiler programme ?

A good move.

Problem sorted, unless you want hot water
Unless you have an immersion heater you'll have to refill the system to get the HW function to work.

I have to ask, if you know so little about the system you are working on, why did you drain it in the first place?

 

[Agile]

The pump may or may not have been damaged.

Until you have tried it with the system full of water you will not know.

Obviously to everyone else the heating system should have been turned off if it was drained as its not designed to run dry and this is likely to do damage to the pump and the boiler.

Tony

 

[ohmygodwhathaveyoudone]

thanks for the replies.
the pump was turned off straight away and was running when at the time.
i drained the system to replace 5 radiators.

 

[ChrisR]

SOunds like air is still in there. Have you bled everything, including the pump itself?? (release the central screw(dribbles))