Problems Draining Waste Water Tank

[johnlc]

I have a 2008 East Neuk Fifer with, I think, a 50 litre waste water tank. On my first trip this year recently, I had problems draining it, even though the warning light for 3/4 full was showing. I could only get water to dribble out at a rate of 5 litres every 30 minutes. The van was on level ground. I've put a couple of bottles of coke down the sinks to try and deal with any gunk that might have been blocking the drain hole in the tank. I can't see any obvious problem on the external drain valve.

Any thoughts on what else I could try?

Thanks

[Derek Uzzell]

I doubt if coca-cola will have any useful effect if your motorhome’s waste-water tank’s drain-hose or drain-valve is well gunged up.

 

A strong bleach solution MIGHT help - let it dribble though into a bucket - but the best thing to do would be to remove the drain-hose and drain-valve from the tank and give them both a good internal clean.

 

If you take off the drain-hose and the tank still won’t drain rapidly, push a garden-hose through the tank’s outlet and give the tank a serious enema.

[Robbo]

It sounds like the outlet from the waste tank has got gunged up, possibly from fatty deposits.

 

Suggest you back-flush the outlet (with valve open) with a garden hose. Alternatively, try rodding with curtain wire to dislodge any debris.

 

Edit: beaten by Derek

[johnlc]

Thank you both for your suggestions. I'll try and get the waste pipe and valve off, hoping that all the connections are not seized up!

Best Wishes

John

[Solomongrundy]

I would suggest you have a plan of 'retreat' from under the vehicle when you take any pipes and valves apart.

 

50 litres of very mucky water suddenly released may be something you need to avoid as quickly as possible.

 

Best of luck.

[Derek Uzzell]

This is an example of the type of drain tap commonly fitted to UK-built motorhomes

 

http://tinyurl.com/m86egdg

 

Being narrow-bore, draining will be slow and this encourages clogging in the tap itself and the pipe leading to it.. However, if that’s the sort of tap your Fifer has and you can attach a garden hose to the tap’s outlet (as Robbo suggested) you may be able to avoid having to remove the hose and/or waste-pipe.

 

There are alternative taps that should improve draining

 

http://tinyurl.com/mw3ef36

 

but fitting a different tap to an existing installation may well prove tricky.

[johnlc]

Derek - thanks for the links to drain taps. Mine isn't one of those and I can't seem to find one anywhere on the internet! No matter though. When the valve was open I could see gunk inside and used a combination of boiling water with washing up liquid in it, and endless poking around with a paper clip to get the stuff out. It seems to be flowing freely now. I'm glad I didn't have to take the pipe off at the tank end. I didn't fancy being underneath when everything came pouring out!

Thanks to everyone for their help