Toilet bowl water level has dropped?

Alphamare

By about an inch. Rises if used but drops again sometime after it's flushed. Thoughts?

Call the letting agent?

Fishingtime

Stop drinking it then :rotfl:

andyhop

Sounds like the stack vent is blocked. Check external pipe work or internal air admittance valve

cyclonebri1

:rotfl::rotfl:, yes it could be the cat drinking it, but more likely it's another toilet or basin etc that is vacuuming your bowl. It may indicate a faulty air admittance valve or birds nest in the stack pipe, either way air can't get in so it tries to pull it from your bathroom.

If it's a flat or tenant block, you mention landlord, then it's even more likely.

nickcc

Water being drawn out of WC trap is usually caused by suction being created in the sewerage system often caused by a blocked soil stack vent.
Or as above

peachyprice

It happens to my downstairs toilet on windy days, could it be that if it's only been happening of the weekend?

Alphamare

It is very windy yesterday and today. We noticed the toilet thing a couple days ago. Don't remember if it was windy then.

I have no idea what a valve thing/stack pipe is or where to look for it?
Is it something we can/should try and fix?

I will probably report it to letting agent if it's something that needs fixing?

It's not a flat but a 2 up 2 down end terrace. Bathroom on the 1st floor.

Thank you all for helping :-)

Ps no cat and the dogs can't go upstairs.
Hubby says he has not been drinking out the toilet in months ;-)

London50

We have had this problem in the past but as stayed it has been on very windy days only, on normal or fine days no problems at all. It may sound stupid be we have put it down to the low pressure systems {weather wise} crossing the country.If the water level in the bowl is not down to below trap level I would leave it until this inclement weather passes and see if things return to normal.

nickcc

Stack/soil pipe usually sticks up above the gutter and often runs up the outside of the house in older properties, new properties have the pipe running inside the house and either venting above the roof tiles or finishing in the loft space with an air admittance valve which allows air in but not out. The vacuum is usually created by air passing over the exposed vent which creates this vacuum on windy days.

cyclonebri1

Given it's a single entry stack, ie, only 1 toilet then it's highly likely it will be low pressure in the stack, and yes it can be created by a partially blocked stack or 1 that is adversely affected by wind, the result is the same, low pressure/partial vacuum in the stack pipe tries to suck water (which it does in part), out of the pan.

PS, the stack pipe is the large dia pipe that runs up your outer wall and collects all waste water, it is open at the top to admit air.

There are variations on this but given the type of property that's a fair assumption of what you have.

Bottom line is so long as you still have an effective air lock in the U bend, ie you don't get a bad drain smell, all is OK.

Alphamare

Thank you for all your help guys!

How do we know if there is an effective airlock?

I will report the problem if it's still there after the high winds have gone, although we didn't notice this in the last high winds? Is it possible it's just happened this time?