Air in Hot Water Cylinder

[homeDIYonly]

Hopeing for some help!

Firstly the system I have in my house - I have a main water talk in the loft, which feeds the hot water cylinder on the first floor. I have a water pump that feeds the hot water for the whole house connected off the hot water cylinder - so when any hot water tap opens the pump kicks into action.

So my issue I had a leaky hot water tap and turned the mains cold water supply off from outside my house and then emptied the water of the cylinder and main water tank in the loft. so no water was coming through my taps. I replaced the washer and then turned the water back on from the mains.

Now my hot water is not coming at all! from what I have read already there is clearly air in the system but when I try the U technique with the cold water is just stops the pump working.

Any suggestions - I am not even sure the water cylinder is full - it definately has water because I hear it filling but doubt very much its full - I think it full of air! is there a way I can air it? so the pump is not effected!

completely lost and this is now day 2 without hot water....

 

[picasso]

You might have air locked the pump, turn off the supply to the pump and the outlet using the full bore isolating valve that was fitted when the pump was installed then disconnect the outlet and run some water through,

any air stuck in the pump will be shifted and you should be back to normal.

 

[homeDIYonly]

thank you for the reply - I did exactly that yesterday so manually pushed water into the pump and the pump seems to be working fine - I even got some water coming through the bath tap very slow but coming through and gurgling - when I turn the taps on downstairs all stops again.

 

[picasso]

Let the water run for a while when you disconnect the pump, it could be air locked between the tank in the loft and the cylinder, sometimes the pipe fills with water and it seems to be a good flow but soon stops, also the pump will probably have a check valve so you cant back fill it.

 

[homeDIYonly]

Thanks for you help - so ended up doing as you say! had to remove the pump and the force the cold water up into the hot water pipes an remove all the air - it seems like air was stuck all over especially in the coil of the hot water cylinder...

once all air was out - we reconnected the pump and just let the water run and all seemed to come good.

thanks again.