Tankless winterizing

[Jratjeff]

I have a tankless water heater. Is it ok to run antifreeze through it? I see where you shouldn’t with a tank.

[TurnerFam]

You probably should, as the copper coils where the heating is happening within the system certainly will hold water unless you have 'blown' out your lines, at least those connected to this water heater.

I'm not sure regular water heaters 'can't' accept the pink stuff, but since they are 'holding tanks', it's probably not a good idea since it will try to 'fill' the tank.

[JamieGeek]

Yeah one of the reasons for the bypass for a tanked water heater is just so you don't have to buy 6 gallons of antifreeze.