Airlock in mains cold water to cold water tank.

[welshdragon63]

Had a ball valve replaced on the cold water tank a couple of weeks ago. Later that day the system developed an airlock. It happens as the cold tank is refilling, and makes an awfully loud humming. Other than calling the plumber back can I fix it myself.. ?

I've tried turning the water off at the mains, opening all mains fed taps, let the pipes drain, then turning the mains back on and opening each mains fed tap a bit at a time starting at the lowest tap (kitchen), but the airlock is still there...

Cheers Phil..

 

[jam1979]

hold your hand on the ball valve out let for a few seconds see if that shifts it

 

[welshdragon63]

Will try, thanks...

 

[jam1979]

no worries let us no

 

[welshdragon63]

no worries let us no

Tried what you suggested but the air lock is still there.. A friend told me to try emptying the tank completely and then letting it re-fill. One thing I forgot to say was, the airlock doesn't kick in straight away as soon as the valve opens, it comes in gradually and gets louder then stops as soon as the valve closes, (as you'ed expect.)

 

[HeBeGeBe]

It sounds as though it's the ball valve generating the noise. If it was new I suggest you call the pumber back to adjust it or re-washer it, depending on which type of ball valve you have.

 

[welshdragon63]

It sounds as though it's the ball valve generating the noise. If it was new I suggest you call the pumber back to adjust it or re-washer it, depending on which type of ball valve you have.

Thanks for that, I will give them a call... Cheers....

 

[SafeGasInstall]

could not be a air lock ! more like partly blocked

 

[welshdragon63]

could not be a air lock ! more like partly blocked

Do you mean the valve not opening fully ? or blocked pipe ?

 

[Best]

It's not an airlock. The humming noise is probably due to the ballvalve vibrating slightly.
Is the new valve just a standard type with the ball screwed directly on to a straight arm? If it is, they can cause noise - they are generally poor quality compared to older valves.
If the valve was a part 2 type with an arm with the end bent at 90 degrees, then it is less likely to vibrate.
Get your mains pressure checked as it might be too high & make sure the mains pipe to the ballvalve is firm.
Use a part 2 valve or perhaps a Fluidmaster side entry valve (brass tail type only).

 

[welshdragon63]

It's not an airlock. The humming noise is probably due to the ballvalve vibrating slightly.
Is the new valve just a standard type with the ball screwed directly on to a straight arm? If it is, they can cause noise - they are generally poor quality compared to older valves.
If the valve was a part 2 type with an arm with the end bent at 90 degrees, then it is less likely to vibrate.
Get your mains pressure checked as it might be too high & make sure the mains pipe to the ballvalve is firm.
Use a part 2 valve or perhaps a Fluidmaster side entry valve (brass tail type only).

Not sure what type of valve it is as I can't actually see into the tank as there is only small gap between the top of the tank and the ceiling.
But judging by what I saw the plumber take away it sounds like the first one you talk about...

I earlier drained the whole system and let it all fill gradually.... Up to now no hum, fingers crossed, watch this space.. If the hum returns I will call the plumber out again to sort it, it just means time off work which I try not to do at short notice...

 

[Best]

If you use a small mirror & a torch you might get a look at it. The part 2 valves have a plastic part coming out of the top of them which is where the water flows out. I suspect you have the other type.

 

[welshdragon63]

If you use a small mirror & a torch you might get a look at it. The part 2 valves have a plastic part coming out of the top of them which is where the water flows out. I suspect you have the other type.

Don't have a small mirror at hand, but as soon as I can get hold of one I'll have a look...

Thanks, Phil...

 

[NeilPlumb]

My opinion is that inside the new part 2 ballvalve behind the seating there's a rubber washer instead of a fibre washer, the rubber washer causes the humming noise. Best advice call plumber back to replace washer with a fibre washer behind valve seating.

 

[welshdragon63]

My opinion is that inside the new part 2 ballvalve behind the seating there's a rubber washer instead of a fibre washer, the rubber washer causes the humming noise. Best advice call plumber back to replace washer with a fibre washer behind valve seating.

It seems to have fixed itself, sort of. I emptied the tank completely and let it refill, not had a hum for a couple of days now...

 

[Best]

It seems to have fixed itself, sort of. I emptied the tank completely and let it refill, not had a hum for a couple of days now...

Unlikely to have stopped making the noise. Probably will start again, just depends on how & when the valve shuts off each time as, for example, if another mains outlet like a mains tap was opened at same time.
Give it a while & if you still have noise then get a part 2 valve or a brass tailed Fluidmaster.

 

[welshdragon63]

Unlikely to have stopped making the noise. Probably will start again, just depends on how & when the valve shuts off each time as, for example, if another mains outlet like a mains tap was opened at same time.
Give it a while & if you still have noise then get a part 2 valve or a brass tailed Fluidmaster.

Not had the noise for a couple of days, tried turning on all mains fed taps to see if it returns but so far it seems fine so far. Thanks for the help...

 

[Best]

Not had the noise for a couple of days, tried turning on all mains fed taps to see if it returns but so far it seems fine so far. Thanks for the help...

That's good, - just leave as is & save your money.
I find most ball valves, especially the part1 valves create a lot of water roar & personally I would prefer in future to use Fluidmasters.