Hot Water Heater problem

I am in need of some advice re my propane hot water heater. I want to know if there are any special skills required to clean the filter in my tankless hot weater heater?

LIttle quibble...it's a water heater...if it was already hot, it wouldn't need to be a hot water heater, unless you really got turned on by it's looks!.

Without knowing the brand and model, it's hard to say what it would take to clean the fliter. Is this in the water stream, or is there a combustion air filter? The bigger thing is likely to be de-scaling the heat exchanger. Unless you have very soft water, that will make the biggest difference in efficiency, and the heat exchanger may need to be cleaned (an acid wash with pump) periodically to maintain its efficiency. If the thing wasn't set up to do this when installed (special valves, etc.), then it can be a pain to do.

Hopefully you still have the owners manual. That should explain maintenance requirements and you will get an idea if it is something you feel comfortable tackling.