Motorhome advice: How to upgrade a waste tap to a flexible hose

On my Auto-Sleeper Clubman, I’ve had to replace the waste water drain tap twice. The plastic becomes brittle and the tap gets stiffer to turn over time until, eventually, the lever on the top breaks.

My Auto-Sleeper drain tap system was not ideal as the hole in the tap was only 15mm, so emptying the grey water out took for ever. Plus, reaching the tap was becoming more difficult as I was getting older, requiring kneeling on wet and dirty ground and reaching quite a way under the ’van. The effort required to turn the stiffened tap also loosened the fitting, leading to a constant drip.

My upgrade was to replace the tap with a 22mm toilet overflow straight tank connector bought from my local DIY store together with a short length of 25mm hose and a 25mm tap (both Hozelock branded), bought from the pond accessories section of my local garden centre, together with two jubilee clips, some rubberised guttering sealant and a super-soft interlocking plastic tree tie. The total cost of all these bits was £15 and the whole job took about an hour.

As the cross-sectional area of the emptying hole has gone from 177 to 380mm2, it will greatly speed up emptying, too. Using a bit of schoolboy physics (and some help from Google) this should reduce the emptying time from 12.4 mins to 5.8 mins!

There is a large screw-on access hatch in the bottom of the waste water tank, so I was able to tighten the nut onto the tank connector with the help of a large box spanner. The ease of doing this fitment on your ’van will depend on the access to the waste water tank – you need to be able to get to the nut on the inside of the tank, so check you can get a spanner to this as a first step.

My upgrade also makes it easier to position the ’van over the drains at motorhome service points as you can move the flexible hose into position. It is also easy to attach to a two-metre drain pipe, which gives many more emptying options. 

To upgrade your motorhome's waste tap to a flexible hose, you will need:

• Large box spanner (or socket or spanner) for the nut
• Screwdriver to suit jubilee clips
• 22mm toilet overflow straight tank connector (from local DiY store)
• 25mm tap and a short length of 25mm hose (both Hozelock)
• 2 jubilee clips
• Rubberised guttering sealant
• Super-soft interlocking plastic tree tie.

1 The old tap with its broken handle had got stiff with age and dripped. Before you do anything else, check you can access the nut holding it in place on the inside of the waste water tank. There’s usually a large access cover either on the underside or top of the tank.

2 The toilet overflow straight tank connector is this straight 22mm version and is normally used as a toilet cistern overflow. Most DIY plumbing stores stock these (and are normally cheaper than the big-branded stores).

3 The old connector was unscrewed from the inside of the tank and the new 22mm connector was tightened using a box spanner. Once in position it was bedded in with guttering sealant.

4 Next, the flexible hose was screwed to the end of the toilet connector and the tap attached to the other end. Loop the tree tie over a chassis bracket and keep it flexible to allow the rear steady to lower and give a little if the tap gets snagged. The tap’s now easily accessible.