On one of the wet days earlier in the week, I fitted a Truma Sonatic Gas Level System into my elderly Avondale. The Sonatic system is a piece of kit developed fifteen or so years ago and was fitted as standard equipment in some caravans. At the time a reviewer wrote about it saying, “As far as I know, this is the only device that actually gives you a true reading of the contents of the bottle. A transceiver unit beneath the bottle sends and receives ultrasonic pulses to sense the physical level of the liquid. Unfortunately, technology such as this comes with a pretty hefty price tag. You have to decide if it’s worth around £150 just to know how much gas is left in your bottle.”

Of course, there are now other devices which do the same thing, but when I saw that Magnum Motorhome’s eBay site was selling the Truma kits for less than £40 (including p&p, I thought it was worth a punt. See eBay item No. 173815837510

This is what you get.

A base plate which screws to the floor of the gas locker, and upon which the 6Kg gas bottle sits, plus the display panel and sufficient cable to connect between the two. To maintain the information within the device, the panel needs to be connected to either a 9-volt battery or the 12-volt caravan supply.

A hole, big enough for the plug and cable has to be drilled into the back of the gas locker to enable them to pass through. Once they are fitted, the hole is sealed with silicone. Then a suitable place is chosen to fit the display panel.

A few years ago I fitted a cigar lighter socket in my van and since I very rarely used it, I removed the socket and fitted the Truma panel into the same box.    The wiring for the display was taken from a fused supply close to the battery box.    All the wiring is hidden within, or behind the furniture fittings.

This is the gas bottle sitting on the pad in the locker.

The connected panel shows the reading for the new gas bottle.

The fused 12-volt supply feeds some additional LED lighting, the rearview camera supply, and the Truma Sonatic’s new supply.