Noisy Central Heating Cylinder

[nodmoore]

Every morning when the central heating comes on, a load gushing noise comes from the hot water cylinder. After 10 or 15 seconds the noise disappears, but only after waking us up.

The heating system is traditional with cylinder and cold water tank. There are pumps on both the central heating and hot water loop to the cylinder.

I assume air is getting in somewhere, but where and what can I do? Help -I need all the beauty sleep I can get ( and so does the missus, but don't tell her!)

 

[MANDATE]

You could start by checking the cold water cistern to ensure the ball cock is functioning and there is adequate water available.
If you have not used any hot water then it is not related to replacing water used
It sounds as water in the expansion pipe which is at the same level as water in the cistern may be expanding into the cistern which is what it is supposed to do, or is it being pushed out by the pump due to resistance in the pipework.
You could make the expansion pipe higher so the water has further to rise before it flows over into the cistern,alternatively you could lower the level of water in the cistern by adjusting the ball cock.Also make sure the end of the expansion pipe is not in the water,you could lower the boiler temperture a little so it does not expand as much and you could try lowering the pump speed.
I think a lot depends on the whether the expansion pipe is connected to the circuit behind the pump (inlet side) or in front (outlet side)
Hope you find these comments useful.

 

[masona]

Adding to Mandate notes, I would turn down the boiler stat first & see what happen,if not then increase the pump setting higher.You need faster flow rate to slow down the heat expansion in the pipe.Slow setting on pump will heat the water quicker to expand.