New fortic keeps overflowing....

[Bunker]

Hi chaps, I fitted a new direct fortic a month or so ago. It keeps bubbling up and overflowing. Its in one side of an old cottage, the other side is serviced by an oil combi. It only serves the bathroom next to it in which is a bath and a sink. The bubbling up happens randomly, even in the middle of the night.
The ball cock seems to shut off ok and is way low enough to stop it naturally getting out of the overflow. The float does not stick on anything.
Any ideas please..

Thanks v much.

 

[Rickster123]

Any dodgey mixer taps with cold main and fortic hot?

 

[Bunker]

Any dodgey mixer taps with cold main and fortic hot?

No, and happens in the middle of the night too..

 

[kay-jay]

If there are isolation valves on the hot try vlosing them at night. If it stops the overflowing you will need to stick nrv on the hot

 

[Rickster123]

Does it happen every night? Have they isolated the mains to it over night just to deffonately rule out the ball valve passing?

 

[kay-jay]

Are you saying the cylinder doesnt supply any mixer taps at all? Or none that you think are dodgy?

 

[kay-jay]

If its indirect it could be an issue with the coil causing it to overflow when heating is on?

 

[townfanjon]

How far is the water level off the overflow level, as the cylinder heats the heated water will obviously expand and the water level will rise.

 

[Bunker]

Are you saying the cylinder doesnt supply any mixer taps at all? Or none that you think are dodgy?

There are none and certainly none that are in use overnight.

Does it happen every night? Have they isolated the mains to it over night just to deffonately rule out the ball valve passing?

Not every night but they could live without it for a few days. Bummer is, the iso I fitted weeps when its off (even though its a Pegler - I only use good ones).

 

[tamz]

If there are no mixers you need to drop the water level.
Tell them to switch the immersion off at night.

 

[kay-jay]

There are none and certainly none that are in use overnight.

.

fair enough if there arent any at all. but if there was they wouldnt need to be in use to cause a problem. pressure differential between hot and cold can cause water to move through the tap itself when it is shut. it shouldnt but it can.

 

[Bunker]

fair enough if there arent any at all. but if there was they wouldnt need to be in use to cause a problem. pressure differential between hot and cold can cause water to move through the tap itself when it is shut. it shouldnt but it can.

Ah I didnt realise that, thanks. Every day is a school day

 

[PhoenixServices]

Has it got a shower off of it. Finding a lot more showers that are pushing through on unbalanced pressures.

 

[Kev the gas]

Is the vent pipe of the cylinder blocked? Possibly the cylinderis filling with air when heating, and the bubbling is air passing back up the cold feed pipe?

 

[Bunker]

Finally sorted this, it was just the ball valve letting by !!!
Thanks for all your answers