Kingspan septic tank not working

[Dan Robinson]

I meant is the water being pulled out of the trap by flow downstream.... For example a toilet connected to the same line.

 

[devs]

Ah okay thanks Dan, I understand. Yes the toilet and shower both use the same line.

I'm struggling to understand why this particular sewer manhole smells so much when theres no blockage and everything is running freely.

I've just been out to try and replace the o-ring on the shower trap but no one stocks anything that size so will have a hunt online later.

Cheers, Steve.

 

[Hugh Jaleak]

Could be a belly in the pipe, causing waste to lie in the pipe, which could cause a hum. Can you put a photo of the problem manhole up, we might see something that you dont realise is an issue.

What ventilation do you have on the system? I assume at least one stack is open to atmosphere through the roof space?

Raw chicken? May help start the decomposition process, but a new one on me. Normal practice is to leave a drop of sludge in the bottom when emptying to retain some bacteria. Sewage treatment is about the correct balance, not enough bugs and the process wont work, too many and they're fighting each other for survival, and again, the process wont work.

 

[devs]

Cheers Hugh, you've been really helpful throughout this. Here is a pic of the manhole in question. As mentioned before everything appears to be moving freely down to the tank.

just looking at the venting and one half of the house is vented but the other side in question doesn't appear to have any vents!

 

[Hugh Jaleak]

Nothing untoward there, sometimes get those chambers especially, where the drains have been laid to too steep a fall, the effluent comes flying in from the laterals at a ridiculous rate of knots and plasters the opposite side, building up in the unused inlet channels. Eventually it causes the chamber to block....

As long as the drain is ventilated at some point, (should be the head of the drain), then that's not an issue in itself, but doesn't answer your issue. Is there a smell at that chamber?

 

[devs]

Thats good to hear Hugh. I can't see any vents from this side of the house and yes its this chamber that can began to smell and its the first one that the ensuite hits after leaving the house.

 

[endecotp]

My uncle mentioned... "that in the olden days... when a tank was emptied you'd put raw chicken in to reactivate the bio system" At first I thought this was mental but its the only other thing I can try!?

Practical joker is he, your uncle?

 

[matgriff]

Now that you've fixed your motor problem, you should really get the red flashing beacon that connects to the control box. Basically the motor shaft has an encoder fitted that sends a pulse back to the control unit to confirm that the disc is rotating. If the disc stops rotating for any reason the control unit switches on the red flashing beacon, that you mount on the wall outside the box where it can be seen. This tells you if the unit has stopped turning (it also signals other faults) The battery in the control unit will power the beacon for about six hours, so for example if you lose mains power (ie the MCB trips) then you get a visual alarm that there's a problem.

Ultimately, if you have a simple system, with no pumped outflow etc, then the control box is just providing a simple 240v to the motor, and an alarm signal for the beacon.... you could just bypass it completely and connect 240v direct to the motor, via a suitable protection device, of course you would lose the alarm functionality..... but you don't have that anyway

I'm an electrical design engineer, and I also have two of these identical Kingspan units that I've fitted at my property.

Mat

 

[devs]

Hi Mat and thanks for that. Yes I agree and will take a look online for one of those this afternoon and get it fitted. It makes sense!

I've still not 100% resolved my issue as our ensuite still has a smell coming from the shower. I'm just waiting on a replacement o-ring for the shower waste to see if that fixes the issue.

Thanks again!

 

[matgriff]

No problem. Also, if you fit the beacon, there's a link that you have to move to connect the battery in circuit, as it ships from the factory with the battery disconnected. It's all documented in the installation instructions.... when you install everything correctly, the little red dot on the LED display flashes to signal that everything is OK.

That control box is a one solution fits all box for all the models in the range, if you just have a simple system (like mine) with a gravity inflow & outflow, then all it does is switch the motor power through and control the beacon. The more complex models have outflow pumps, level sensors etc, that's when the control unit has to provide more functionality.

You really need to know if the unit stops turning, because in that case, you'll just be discharging direct untreated s**t into the water course, and the solids won't be getting broken down...

Mat

 

[Hugh Jaleak]

In fairness, the unit will still provide a degree of treatment if the discs are not rotating, but to achieve full potential and quality of treated final effluent, the unit does need to work as designed. Basically, the 'middle' section where the discs are provides bacteriological treatment to help remove ammonia and other nasties from the sewage, the discs helping the bacteria to do their job very efficiently.

It works on a very similar principle to a small sewage treatment works, primary settlement, biological filtration, and final settlement. Excellent advice there from Mat though, an early warning system to tell you the discs have stopped rotating should really be a standard fitment, as otherwise the fault may not be noticed for weeks, even months. Meanwhile the unit is failing to treat the sewage effectively and possibly polluting anything downstream of the discharge point!

 

[devs]

Joy, one year on and I've spotted that the discs are not turning in the tank. The fuse switch is being tripped! Question.. I've just booked it in to be de slurried not sure if its full or not? If it was full could it stop the discs and trip the switch?
Just trying to figure out if I need to look to a repair or just wait for it to be emptied? Thanks!

 

[Hugh Jaleak]

I'd think it would have to be almost solid in there for sludge build up to stop the discs turning, and to get to that stage on a domestic property would take a long time, coupled with excessive usage, and/or a regular large discharge of cooking fat or similar which could congeal in the system. To be honest, I'd expect the house drains to start backing up before the Biodisc gave a problem in that instance, and the only time I have ever come across this scenario was in fact at an Indian Takeaway. He'd called us out to empty his tank as his drains had backed up. On opening the Biodisc I was faced with one solid lump of fat, it was so bad. The only way that could be dealt with was by specialist cleaning contractors, using high pressure water to break up the fat and a tanker to remove it.

Most likely issue in your case I suspect is motor failure, either the motor is worn out, or has failed due to excessive load, possibly due to seized bearings on the shaft. (The bigger versions we use for treatment of flows from small villages have grease points fitted to allow grease to be pumped into the bearings as required.) It wont hurt for a desludge I am sure, and also means it's slightly sweeter in there for the engineer to work on it!

 

[devs]

Hi Hugh and thanks for getting back, appreciated mate I replaced the motor Only last year And had hoped that it would have lasted longer considering the price of it! I’m yet to check things out but what would cause a motor to fail quickly or for a capacitor to burn out? Thanks

 

[Hugh Jaleak]

I can only think it has been either overloaded, has got wet inside, (should be moisture sealed given the application), or there was a issue with the new motor from the start which has shortened its lifespan. In normal operation, on a properly maintained system, I'd expect the motor to last many years. Check how free the shaft is to rotate, but bear in mind if the discs haven't been rotating, the wet section will be a lot heavier than the top half that has been sitting out the water, so will be extremely unbalanced at present. Given the weight of the discs, and if the shaft/bearings are stiff, then this would put a lot of additional load on the drive system.

What do the Biozone/discs look like? If the discs are heavily coated with gunk their weight will increase massively, which could put additional strain on the motor, but in normal operation the Biozone should just contain water with small particles in suspension, if it looks like there is a lot of waste material in there you may have another issue which would require investigation. The solid waste should be retained in the primary section and break down into sludge.

Do not underestimate the weight of the plastic discs when wet, I attended a job where the maintenance crew wanted to remove the disc assembly for a large version of the Biodisc, it was calculated the weight would be around the 8 tonne mark, and a crane was duly sourced to perform the lift. In the event the crane struggled to pick it up, the driver said he was close to the working capacity of his machine and he estimated he'd got closer to 11 tonnes on his hook!