Couple of questions. Help with dripping hot water line with tankless propane hot water heater and well and Washer

[iyiyi]

I have a well and a tankless hot water heater (propane). Is it safe and recommended to let my hot water lines run (that are on exterior walls)? Could this cause issues with either the hot water heater or issues with propane since I'm assuming it will be kicking on all night?

Also, unrelated, I have a washer that has pipes against an exterior wall. Is there any easy way to let those drip somehow?

 

[breplum]

You will definitely be using considerable propane, how much depends on how modulating of gas the tankless is. Most won't kick on at all until .5 gpm which is a high threshold if you only want to prevent freezing by letting water drip.
for the washer, you'd have to disconnect the water hoses and shove into a drain or utility sink.
Don't forget to descale tankless WH at intervals appropriate to your water quality. mfrs say annually.

 

[Twowaxhack]

If the tankless is inside where it can’t freeze then you turn the tankless power off then drip or run your hot faucets. That way you’re not using propangs. I call it propangs not propane.

 

[GReynolds929]

Are the pipes that you're trying to prevent from freezing on the outside of the house exposed to the elements? If that's the case there's not much besides heat trace that will keep them from freezing. What are your lows normally in the winter.