running toilet inlet

[Andy Whiteley]

I have recently fitted an en-suite bathroom to a new extension in a bungalow. The toilet is a concealed cistern type and every time the owners run the bath in the original bathroom, the inlet on the new toilet in the extension starts to run. They flush it when this happens but it continues to run. I have changed the inlet from the original to a fluidmaster valve but the problem persisted. So I have changed the valve again, this time to a Torbeck valve. As yet they have not been back to me But I suspect they will!. Any ideas as to why this might be happening. I have sought the advice of a very experienced plumber and even he seemed baffled by it.

[Paul McNamara]

Andy,

It could be a case of the water pressure in the house dropping far enough to unbalance the valve and let water through??

Paul

[Andy Whiteley]

Thanks Paul, any suggestions as to how I might overcome this. I have fitted an isolation valve on the inlet pipe of the toilet, would a double check valve stop this happening ?.

[Neil]

check valve will not stop poor water pressure
is cistern fed off tank or mains ?
if tank try it on mains u may have to fit the plastic restrictor in the torbeck valve hp or LP IF I REMEMBER LESS THAN
1PSI FIT LP
ABOVE FIT HP9N

[Neil]

JUST HAD ANOTHER IDEA - IS CONNECTION TO WATER VALVE IS IN FLEX CONNECTION? THIS SLOWS FLOW INTO TANK - IF SO, PLUMB IT IN COPPER [15MM]

[Andy Whiteley]

Thanks Neil, the connection is straight from the mains and in is plumbed in copper, no flexible fittings. I have tried both ways, with the plastic restrictor in and out and it made a small difference with the fluidmaster valve but it didn't completely cure it.