Toilets backing up/gurgling....?block in septic tank/sewerage system?

[Ula NI]

Hi there,

We have a two story house with its own sewerage system.
we've noticed the water level in two of our three toilets has been either low, or when flushed rises up and is slow to go down. Also, when running taps in the upstairs bathroom - which has been recently renovated- gurgles a lot, you can hear the water going down the outside waste pipe! My Dad suggested a block somewhere in the system. I've uploaded a photo of the septic tank below, not sure i should be seeing water in it, think it should be 'crusty'. Septic tank was de-sludged in November.

Any idea of where to start?
Can we try to use something to search for a block ourselves?

Any and all advice welcome.

Thanks

 

[KenGMac]

GemsNI, good evening.

Must admit, not an easy problem to give advise on?

You mention in the post that there has been a recent adaptation of the Plumbing system? was any of the pipework extended? meaning were the lengts of drainage pipes made longer?

If so there is a Possibility, I stress Possibility that the lengths of pipework within the house, away from the External? Soil stack that itself is vented to air could be causing a form of "Back Siphoning"

As I recall, the Soil stack [whether internal or external] is as above vented to air, but the pipework internally does not have a vent to air. so the "plug" of water filling or partly filling the soil pipe internally can "Draw" or suck the water in the WC trap is sucked away by the "plug" of water either filling or part filling the waste stack.

Hope I am so far making some sort of sense?

As your post there is a possibility that there is a partial blockage? that can only be verified by a CCTV Survey, [at a cost?]

OK back to the above mentioned "Back Siphoning???"

Suggest you have a look at "Durgo Valves" on line?

These things admit air into a long run of un vented pipework, but, they do not allow Sewer Gas and smell into the property, there is also a version that fits on to the top of the main 100.mm. Soil Stack if the Stack is installed internally [and you do not want to vent through the roof?] There also smaller versions that come Pre-Fitted to a Wash Hand Basin trap, trick is to fit these type of valves at the highest end of the internal pipework run, generally a Wash Hand Basin.

Hope some of the above assists?

Ken.

 

[Burnerman]

Are there any inspection chambers (manholes) near the house?
If so, lift the covers and see what you find, there should be no standing water visible.
Often, bathroom refurbs often mean tile cement and grout being washed away where they shouldn't have
John

 

[Newboy]

When the bathroom was renovated was any alteration to the waste pipework (specifically the stack) made.

Any pipes removed or altered/shortened?