Every time I turn off a tap my toilet starts to overflow?

[MISS S]

Hi, can anyone help with this one? A couple of weeks ago I noticed my toilet was making a high pitched noise every now and again when I flushed it, but if I flushed it again is stopped. Now, every time I turn a tap off in the house/use the shower/washing machine or dishwasher, my toilet either starts to make this high pitched noise or increasingly has started to overflow. I then have to flush the toilet to make it stop. This problem seems to have started round about the time I started to use my central heating again which hasn't been used all summer but this could just be coincidence. I have a combi-boiler. Anybody know why this has started to happen and if there is a way I can resolve it?
Thanks.

[johnmcginty]

Change your inlet float valve , or the washer for it.

[Plumbstar Tom]

wont be anything to do with your heating

the washer or diapragm on the inlet/float valve is failing and the changing of pressure from a tap turning off for example is causing the issue