"Our heater products are designed to run on fuel to specification BS EN 590 as stated in the Technical book that accompanies all heaters".
It is commonly thought that red diesel is road diesel with a red dye in it. Unfortunately, this is not always the case. There are two types of red diesel available, one is Gas Oil with red dye, and the other is Low Sulphur Gas Oil (City Gas Oil) with a red dye. The latter meets BS EN 590 and has the same specification as road diesel.
We have contacted a couple of Fuel Suppliers to ascertain "what exactly is it in the fuel that makes it different".
The main differences between "Gas Oil (non BS EN 590)" and Low Sulphur Gas Oil (to BS EN 590), is the former has a lower 'Cetane rating' 46 against 52, higher sulphur %Wt 0.2 against 0.005, higher Flash point 82 against 67 and Carbon residue, on 10% distillation residue, %Wt .12 against <0.001.
The fuel commonly found on the canal system is unfortunately "Gas Oil". The other "Red diesel" available is called "City Gas Oil" (ultra low sulphur gas oil) (Linton Fuel Oil Ltd Stock code 103). This meets BS EN 590 and apparently costs the marina only 1.5 pence more per litre. Our contact was quoted saying "why anyone chooses to buy normal gas oil, I don't know!" another supplier was challenged to why it was not always offered he said "surprisingly no one asks for it but it is readily available".
We have found boat owners using the better quality fuel to have a longer period between servicing, therefore what is needed are people like you demanding this far superior fuel. I am sure you would be happy to pay a few pence more for better fuel.
In answer to your servicing questions our heaters have a service interval of approximately 2000 hrs, this can be adversely affected by the use of Gas Oil (non BS EN 590), bacterial or water contamination. We have many customers who have taken onboard the advice we have given in the past regarding additives and now have far longer service intervals. Additives such as 'Fultron' are available from all good chandlers and stockists.