How can I find if we have a hidden manhole

[FedUpWife]

Drains from kitchen are glugging.

I have rodded all available drains and there is no blockage, but the kitchen is still glugging and not clearing efficiently.

I have even poured food dye into the running water so I could obviously track the waste and it is not coming out anywhere.

I can only assume there is a hidden manhole, how do I find out?

 

[muggles]

Look on your house plans, any manholes should be shown on them

 

[FedUpWife]

Look on your house plans, any manholes should be shown on them

I am not sure we have a copy, do you know where I can find them please

 

[muggles]

If they're not in your house, they may be with your solicitor, mortgage company, local council, estate agent, or they may no longer be available. In some cases, the Land Registry's documents relating to your property might help. Your local water authority may have a record of where they are, too. Failing that, you'll need a metal detector and a shovel

 

[Ian400]

I have had this problem, for a long time I couldn't find a manhole. Then we had snow,
And there it was. The warmth in the drain had melted the snow on the concrete covering the manhole. I realise this is a long-term solution for you, and not very helpful right now.

 

[Blagard]

Drains from kitchen are glugging.

I have rodded all available drains and there is no blockage, but the kitchen is still glugging and not clearing efficiently.

I have even poured food dye into the running water so I could obviously track the waste and it is not coming out anywhere.

I can only assume there is a hidden manhole, how do I find out?

You are assuming the sink is connected to the right sewer. Generally you will find reasonable access on most foul drains but not so on the storm where there may not be a manhole, only an underground pipe junction.

You "might" find a storm manhole near the boundary of your property so if you get your dye to show there you might also try some down a rainwater pipe to check if it is storm! Depending on the age of your property drawings can be very unreliable for drains. I got a copy of the BC drawings for mine (1937) and found the drainage nothing like the drawing!

BC plans may not be with the deeds, you need to dig deep to find them (sorry for the pun!). If not too old the local BC department may have them. In my case I had to go to the local records office and examine drawings they had archived. I knew just enough about the house history to track them down.

 

[rjm2k]

Can you access neighbouring manholes? If you can work out which ones are connected and the direction of runs you may get an idea where yours is.

 

[polesapart]

Dig

 

[Hugh Jaleak]

Age and type of house? Not given that any property will have a chamber, some may drain into neighbours, and share a chamber, others are directly connected to a 'spine' drain in a herringbone fashion and there may only be a chamber at each end. The Victorians could be sparse with manholes, and a number of properties in the post war building spree (especially Local Authority Housing) may only have a manhole on every 3rd or 4th house.

Desperation could lead to use of a metal detector, but unless there is a metal cover to find (and not a concrete slab) it wont help..... Other option could be water divining, not foolproof but can point you in general direction of drain runs. (I am being serious.)

 

[GavThePlumber]

Has self siphonage been ruled out? How long is the run from sink to drain?

 

[Blagard]

Have you tried dosing with one of the blockage clearing solutions on the market? - Getting it in after any obviously clear pipework would be best.