In-tank probes or frostat's, as they are generally known, are currently fitted to many motorhomes.

The majority of installations have only one probe fitted to a fresh or waste water tank. But, a single in-tank probe can only protect 45 litres of water from freezing.

Fresh and waste water tanks are generally around 110 and 60 litres respectively.

One in-tank probe with a capacity of 45 Litres will not prevent a 100 Litre tank from freezing.

In-tank probes are suspended in the tank, so the water at the bottom of the tank has very limited protection.

In-tank probes are suspended in the tank which means that during installation the tank has to be drilled with a risk of leakage in the future.

TankBlanket is positioned next to the outlet pipe which is the first areas to form ice if there is no protection.

Two in-tank probes have a capacity of circa 90L and are more expensive than one TankBlanket at 121 litres.