Help to Stop Waves

[stem]

Sometimes when we use our power shower, a 'wave' develops in the F & E tank that supplies the hot water cylinder, and the cold feed for the shower pump. This wave, causes the ball valve float to rise and fall, so the water entering the tank fluctuates correspondingly, which seems to exacerbate matters.

Because of the fluctuating ball valve, this then effects the cold water pressure to the rest of the house, so if the WC or any cold taps are open they have a supply that rises and falls in approximately 2 second cycles.
Once the shower is off, slowly the wave subsides as the tank refills. The shower works perfectly and is not subject to any fluctuation in pressure or temperature.

My real concern is that in the kitchen, the piping is a combination of copper and plastic pipe with 'push fit' connections. The connectors 'creak' and 'crack' alarmingly in time to the pressure swings.

This gives rise to three questions that I would like answers to:

1. How can I stop the 'wave' developing?

2. Is there a real risk of the fluctuating pressure causing the push fit connectors to work off?

3. Why does it only happen when the shower is used, and then in only approximately 1 out of 10 to 20 times that it is used?

Thanks in anticipation.

 

[footprints]

The pressure fluctuations should not cause problems with most pipes because they are mostly designed to work on mains pressure.

I have heard of paddles being fixed to the ball arm to act as a damper to reduce movement, can't find anything with a quick search but I guess you can imagine the sort of thing.

Edit Also small container (plastic cup) suspended from the ball arm with stiff wire and immersed in the water.

 

[ALCPlumbing]

Is the ball valve in the tank a proper brass style one with a ball on the end. I once saw a tank where someone had fitted a plastic torbeck valve designed for a toilet that was causing the same problems.

 

[algas]

You sometimes need to fit a metal plate on the outside of the tank to stop it flexing, another way is to put a 90 0/0 bend on the float arm, you may have to heat it up with a blow lamp first as modern brass is quite hard & may snap.

 

[stem]

Is the ball valve in the tank a proper brass style one with a ball on the end. I once saw a tank where someone had fitted a plastic torbeck valve designed for a toilet that was causing the same problems.

It is a brass valve, Portsmouth type.

 

[stem]

You sometimes need to fit a metal plate on the outside of the tank to stop it flexing, another way is to put a 90 0/0 bend on the float arm, you may have to heat it up with a blow lamp first as modern brass is quite hard & may snap.

It does have a metal plate already. Thanks for the 90 degree tip, I'll try that after the cup on a wire tip suggested by footprints.