I've got an R85 that was probably installed around 06 or so, in an exterior wall, it took a dump on the 7th. Replacement is to be installed tomorrow, but my plumber said the new ones are deeper and therefor it needs a lid extension since it sticks out further. It didn't come in with the heater, I told him I don't care and have to have hot water. Lid be damned, its been too long.

I've been googling and can't find what he's talking about, any of you plumbers know? Obviously its a different lid that's supposed to work with my existing box, I'd just like to see it.

We have a Rinnai wall mounted one similar to that.

I can't imagine what "Lid" he would be talking about?

Ours is a complete unit and there is no lid on it anywhere.

Is this in a recessed wall box? We don't have those here, never installed one like it but thats what it sounds like. Thr new unit will stick out a little more.

The R85 looks like the one we have (I don't remember the model number?) and it just mounts flush to the wall.

Mine is mot in a recessed box it's just bolted the side of my garage I think you'll be good mine is a 2006 model

R85 is no longer made according to google, the new one is a little different.
here are the specs for both.

r85
Specification Table
Minimum / Maximum Gas Rate (Input BTU/Hr.) 15,000 – 199,000
Dimensions: 9″D x 14″W x 24″ H
Weight: 48 lbs.
8.5 GPM Maximum Hot Water Capacity at 35° Rise
4.5 GPM Maximum Hot Water Capacity at 75° Rise
NoX Emissions Less Than 40Ng/J
Temperature Range 98 – 140° F
Altitudes Up to 10,500 Feet Without Kits or Additional Parts


rl 94i is what it shows replaced it.
Specifications
Dimensions: 14” W x 23” H x 9” D
Weight: 43.7 lbs.
Installation: Interior/Residential or Commercial
Approved Gas Types: Natural Gas or Propane
Minimum/Maximum Gas Rate (Input BTUs): 10,300- 199,000
Hot Water Production: 0.26 to 9.8 GPM (35° rise)
Energy Factor: 0.82 (NG and LP)
Electrical: AC 120 Volts – 60 Hz
Connections:
Gas Supply: ¾ inch MNPT

Cold Water Inlet: ¾ inch MNPT

Hot Water Outlet: ¾ inch MNPT

I only see a 1" difference in height if he is using the second one, both are same depth/width.

find out what model he is installing, if you need a deeper hole get some treated 2x4 and fur out the wall, be sure one side is screwed to a stud and sandwich a 2x on the other side to screw fur out to. ours were a direct replacement when they got replaced so no difference.

I wouldn't have a tankless in my house

You loose power and your done. My gas water heater works fine without electricity

This. I thought about going tankless on our new house, but after this encounter with cold weather I'm staying with a gas water heater.

we have 2 of these on east facing walls, same as last ones that lasted about 15 yrs. and up to now never a problem one out of them, even though they froze for a couple of days there is no damage/leaks.
as soon as I get some dam propane I see a 30 min. shower in my future.
I am a fan.

Agree. We lost power, but hot water, we had.

I saw about 8 house flooded today due to tankless that stopped working during the freeze, and some of them never lost power.

I also saw 3 tankless that actually split in busted

POS