I have not yet had the opportunity to look at one of these units live.
I assume if you installed it in the shower thay are waterproof?
Well sort of waterproof. Ours is installed about a foot down from the overhead with a stainless plate that goes up the bulkhead and across the overhead just above the vent. It deflects the heat and prevents any problems with the overhead. The shield never gets too hot to touch. The very top of the unit does get quite hot. The unit vents straight up. If you look down into it you'll see the burner flames. It's not water
tight but when you use our shower
you pretty much just use the hand spray that is removable from a wall mount below the top of the heater and to the right. There is a seat in the shower. It's not like a stall shower in a house but the shower area has it's own floor to contain the water
but has no door it takes up about half the space inside the head
. The shower is not totally enclosed but the head
isn't all that big either. It does have a solar
vent in the overhead and an operable port. The solar
vent is in the shower as well. The ODS has never shut off the burner or tripped the CO detector. Even to old one that wasn't that well adjusted never did that either.
If you need to install it in a tight space with no venting to the area then you'll need a flue. It's pretty hard to find a place on a boat for a flue. We have one for the diesel
heater but I have a cap that fits on top when we travel. That would not be totally bad for a water heater except you won't have any under way.
The PO installed a Bosche ventless unit 20 years ago and they lived on the boat for 7 years. It worked well but did have a standing pilot light you had to light. The newer Excel unit is not as deep so mounts closer to the wall than the old one did. I love the electronic ignition with no pilot light required. It's very quick and avoids pilot light issues. It means you just turn on the solenoid for the propane
tank and your hot water heater is automatically ready. I do have a shut off just before the propane
inlet that I can manually keep it off. If the propane is off it just flows cold water.
I suppose I would not have picked the location as being there but I really can't find a better place for it. Inside the head means it helps dry it out when showering and it is warm in cold weather
You have to deal with condensation
from the propane burning and there is no escape from that. You need some way to vent the heat and moisture but I don't feel a flue is mandatory if you have an alternative method. You can NOT install a ventless unit inside a locker. You could install in the galley
as they are usually open and can be vented by ports