Smelly Grey Water Tank 7 Comments

Bad eggs in grey water tank

Rotten egg smell in your’s why and how we get rid!

The grey tank holds all your shower and dirty water from your sinks. Like most people, we drain our grey water on a regular basis and get rid of the smelly water. Unfortunately, all the nice smelling cleaning products like soap, shampoo and washing up liquid that go down the plug hole end up sticking to the wall of the tank. The once fragrant product take on a whole new meaning when it builds up in the tank. The fresh bergamot, rich amber with warming notes of exotic coconut, vanilla and almond no longer remind you of the caribbean breeze but more like the chicken farm with the smell of rotten eggs. Jeez, and if its summer time, hold ya nose.

So what do we do?

We clean our grey tank on a regular basis to prevent any unnecessary build up inside the tank and also, prevent any nasty smells. At the same time, we also gently clean the gauges/sensors located inside the grey tank that tell you how full your tank is. We don’t have a routine or set timescales but probably every 2-4 weeks when we have access to a reasonable high pressure water source.

Where is the grey tank?

2016-06-26 at 12-35-09-TipsGrey tanks are located in different places but ours is to the rear of the motorhome. We can access the inside of the tank from inside our van. Under one of the floor panels we have a large blue screw off lid, this is the lid to the tank. Unscrew the lid and you now have access.

First job

Find yourself a decent service point with reasonable fresh water pressure and a good grey water drain facility. Suggest you only do this at non peak times – just good manners towards fellow campers.

Tools for the job

You will need hosepipe with spray gun attachment. Check the hosepipe is long enough to reach from tap to grey tank.

Get ready

Empty the grey tank of any dirty water and leave the tap open. Connect up your hose pipe with spray gun attachment and get ready.

On Ya Hands n Knees

Cleaning Grey TanksInside the motorhome and unscrew the blue lid. Place the hosepipe with the spray gun fitting inside the grey tank. Release the spray gun trigger and off you go. Slowly move the spray gun up and down, back and forth, inside the tank until you have hosed down all the walls of the tank. Remember gentle and don’t go mad, otherwise you will end up like a drowned rat.

Sensors Too

Our grey tank sensors are located just to the left. Gently place your hand inside the tank and you should feel 3 steel rod thingy’s. These are the sensors that relay how full your tank is. We gently clean the sensors to remove any build up but be careful not to damage them, they can be quite sensitive.

Feeling Really Lucky

Cleaning Grey TanksAnd if you are felling lucky, you could also clean the sink pipes too! By choice we bought a small spray gun but by sheer luck the diameter of the spray head is the same size of the plug hole. We place the spray gun over the sink hole and pulse the water. Press and release the trigger quickly. This helps remove any build up in the pipes.

For the extra touch

With tank clean, close the drain tap. Pour a few caps of bleach (optional) into the tank and about 10 litres of fresh water. Replace the blue lid, tidy up and off you go. Whilst you drive, let the water and bleach mixture slosh around inside the grey tank to kill any bugs. Safe dispose of the water and bleach solution after about half an hour.


Whilst one of you is cleaning the tank the other person can stand outside and watch the blobs of yuk disappear. Strangely enough they look a bit like scrambled egg, which sort of align with the rotten egg smell. Anyway, watching it disappear can be a strangely rewarding feeling is a bazaar way.

Leave the best but until last

Cleaning the grey tank is not sexy or exciting, it is a horrid smelly job but it can be fun. In summer, a wee cheeky ‘oops sorry’ spray on your other half just before you pack away always leaves a need for sweet revenge. Catch me if you can!

And if you are not up to cleaning the tanks just grab a few pegs and pop on the fan to blow away the smell!

Everybody has their own way of doing things. Our way is not perfect but it is how we have learnt to keep our grey tank clean and smells at bay. We are always open to new suggestions, so if you have a few tips we would love to hear from you.

We bought our mini hose pipe from Wilko

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