Final Problems At The Last Hurdle – Gas Leak & Modified SOG Switch

Having had our new refillable gas cylinders fitted, I took the motorhome to our local petrol station the next day to fill them at the LPG pump.  Result – £26 of LPG filled both cylinders, less than the price of a single replaceable cylinder from Calor.

I switched on the fridge to start cooling it down in preparation for us leaving. Later I could smell gas from around the gas locker. At first I dismissed this thinking it was from the initial filling operation.

But over the next day or two the smell of gas got stronger and I could even smell it on the driveway outside the van. The error light came on at the fridge and when I checked the cylinders, the one I had switched on was empty. It was now obvious we had a leak somewhere in the gas system.

This was strange as the engineer the previous week had checked all the appliances and gas pressure. Then it clicked that this had been done with the existing cylinders as he checked the system first, and then fitted the empty Gas-It cylinders. I felt there must be a leak somewhere in the new hose connections.

Luckily we had booked the engineer to return the day before we were due to leave to connect up the new water heater and install a SOG system to the Thetford toilet.

When he returned he assured me that he had properly tightened all the new connections and true to his word, when he checked them they were all tight. So out came the pressure tester again and some leak detection spray (soapy water in a spray bottle!).

It didn’t take long to detect the leak. There was a straight compression joint at the bottom of the gas locker just where the main gas supply pipe exited and he admitted that he must have nudged against it when putting the new cylinders into place. It was a bit of a pain to tighten as one of the nuts was inside the gas locker and the other one just outside, so we both had to crawl into the garage/boot and I held one nut in place outside the locker with a spanner as he tightened the other nut inside the locker.

With this problem sorted, he then made the connection to the water heater, and I breathed a heavy sigh of relief as I heard it fire up a couple of seconds after I switched it on :-). It produces lots of pumping hot water.

Now it was on to the final major job of fitting the SOG unit. These systems vent the toilet cassette with the help of a small, low current 12v fan. This keeps toilet smells from entering the van, and with the help of air moving over the cassette, helps to naturally break down the contents without the need to use caustic chemicals in your cassette system. All good fun!

He drilled the hole in the locker door and fitted the fan unit inside and the carbon filter and housing outside the door. Our model of toilet requires a hole to be drilled into the emptying pipe to connect the breather tube. Everything was going swimmingly  until it came to fitting the last piece of the puzzle – the micro switch which operates the fan when you open the blade on the toilet.

An aluminium sheeting had been fitted to one of the inside walls of the cassette recess which angled out just where the micro switch needed to be fitted and prevented it from fitting in the correct position. After some head scratching, it seemed there was no way to alter the micro switch and bracket to fit properly – well not inside the time we had remaining until it was time to leave. Another brick wall.

Modified wiring in the cassette compartment to the back of the switch on the left

Then I came up with the idea of fitting a manual switch to the front of the toilet which could be switched on to activate the fan while the toilet was being used. I had a stock of 12v LED round switches. We decided on a positioning of the switch and I drilled a hole through the front casing of the toilet. We ditched the micro switch and connected the  wires to the manual switch.

Now this idea might seem crazy at first, but as I pointed out to the engineer, the SOG unit fan with its original micro switch design only operates when the toilet blade is open, and switches off again as soon as you close the blade. With my newly engineered set up, we can close the blade and leave the fan running for as long as we like to vent the cassette! This will be especially useful if you have annoying neighbours who park too close and you want to remind them of the fact :-D. The small fan unit uses such little power that it will not have any real impact on battery life.

Switch unit neatly installed on front of the toilet

The idea was almost perfect – but the back of the switch which protruded inside the cassette chamber made it awkward when pulling the cassette in and out of its compartment. So the next day I further modified the design  by getting a normal socket surface patress box with a blank front cover, drilling a 20mm hole on the front cover and reinstalling the switch to move the connections further forward away from the cassette.

To date this system works perfectly at operating the fan and even more so at keeping smells at bay.