Did they explain why the new gas line is a code compliance issue, not just a performance improvement? If the new heater is about the same BTU, and the old line worked, why do you need a new gas line?

I don't disagree that its a good idea to make sure the gas lines are sized properly, but I'm also sure that running the new 1" line is a fairly significant part of the cost. Running the drain for the smitty pan may also be costing quite a bit if it requires some significant changes to get it to run to a proper drain area.

Do you also need to install an expansion tank, or would that only be for a traditional water heater? If they are going to install new metal venting, that is also a fairly significant material cost for the proper stainless steel pipe for a tankless. However, it looks like the Rinnai can also use PVC. The isolation valves make sense, since most manufacturers recommend periodic flushing of the tankless heater.

Bruce

I have 3 quotes, and 3 quotes tell different stories at different price ranges: cheapest Quote at 3k include labor and materials but very little work, labor only quote at 3k+material but can’t figure out vent and drain, 14k has everything and maybe too much.

I went to look up California plumbing codes. There’s no other specific municipal codes I can find. In the code about water heater - gas, the only pipe related stipulation is that it should be enough to support pressure. The old Takagi tk2 is a 3/4”, the Rinnai ruc80in is also a 3/4” pipe, plus the rinnai is actually only 1520k Btu compared to the Takagi 18xxk BTU, so it doesn’t seem to be reasonable do the 1” gas pipe run work.

All 3 vendors said to do valve related work, so that seems legit.

Vent discharge to outdoors is also code required. Labor only quote said he can’t find an outdoor vent and want me to get a roofer to do that, cheapest quote doesn’t include that as work, the 14k quote said to use existing roof vent opening but need to install new termination kit - not sure why existing cannot be used.

The drain line out is another code requirement. Labor only quote says they can’t figure out where to install the drain line - I have to sign liability waver. cheapest quote doesn’t include it, the 14k quote wants to run it along the gutter if HOA approves. I’m waiting to hear back from neighbors and HOA members - seems incredible that we don’t have one built in the house.

Then there is the new copper pipe - labor only quote said the old pipes were welded to the water heater so new ones have to be cut. Not on cheapest quote but on 14k quote.

My neighbor said he went to the 14k company and got a verbal quote of 6.5-8.5k quote - we have very similar units and have same existing installation.

The whole thing sounds very fishy here...

Yeah, the point is that $14k for for a water heater is out of line.

You need someone who can look at all of the options:

1. Can you simply replace with a similar unit and be done?

2. Can you replace with a different unit, but not one that would require replacing the gas line?

3. What's actually code in your area? What is being added that isn't code? Are you required to have an earthquake valve on a tankless unit? Are you required to have a drain pan on a tankless unit?

4. Can venting be changed for savings (PVC venting on a condensing unit) to save money?

5. Can you scrap the tankless completely and just install a gas tank unit, or a electric hybrid unit?

Let me add a couple of things:

1. You need service valves - that's legit (~$80)

2. You have flex supply lines that will be replaced with new flex lines or rigid copper... that's not a big cost item. That might be $20 in parts and $100 in labor.

3. You need a drain. At minimum you need the T&P valve to go to a drain or discharge to the outside. This is required on any type of water heater.

The identical unit is no longer in production. supposedly the rinnai is a similar unit and lower BTU, so I really don’t see why need the gas line - even if the vendor kept saying code compliance, I can’t find any code that requires 1”.

CAL requires both earquake valve and pan with drain line to the exterior, so that seems unavoidable. I just find it incredible that drain out is not part of the house.

Code also says gas units have to vent outside. I assumed the termination kit is a PVC, but will check. Still don’t know why existing ventilation installation system cannot be reused... unless there isn’t one.

Unfortunately the attic is tiny so no place to change to a tank version, need to stay with gas tankless.

Sounds like the gas pipe is most dubious, other items more or less unavoidable? In that case, what would the a reasonable cost range? Thank you for your help.

Gas line sizing is based on BTU and length. Here is the info from the manufacturer. See page 41 for gas line sizing.

Of course you have to have a vent. It looks like the old one was metal(?) and the new is PVC. You can't connect to a metal vent if the new one is PVC.

It looks to me like the install from 2005 didn't meet code (undersized gas line and no drain).

I would still talk to someone who gets it that $14k is crazy for a water heater and how can this be fixed.

Gas line sizing is based on total load, and it should be calculated for a specific installation, not just a SWAG. Before spending a lot of money on upsizing the line I would want to know that an installer had actually calculated the load and that the larger line was definitely needed.

The drain requirement may be new since whatever code was applied in 2005 when it was installed. Based on Section 504.7 of the International Plumbing Code, tankless water heaters do not require a drain pan, and when you replace a water heater without a drain pan, you do not have to add one. However, local codes may supplement these requirements. I know that in my area the plumbers believe they must always add a drain pan.

Bruce

too bad you dont have power to the location. put in an electric water heater

I’m asking the installer to produce a justified reason for the gas pipe work that matches the numbers listed out in the user manual - thank you Jake. Thank you Bruce for showing the comparative code for draim pan - that gives me some thoughts. I do have power there but no space to have a tank, the attic is too small. I’m now thinking if it is possible to change to an electricity run tankless water heater instead of a gas one. This way the vent or the gas will become none-issue. May have to upgrade electricity circuit but that seems to be cheaper?

That is an option, but the electrical upgrade is significant and it's expensive to run. That said, it's not $14k expensive.

Here's something I really don't say often...

What about someone who will replace the heater with a similar heater (I know, not that exact one) and call it good. No bringing it up to current code, etc.

It needs to be safe - so if it's a metal vent, you need to use a heater that uses a metal vent (not a condensing unit) with a similar BTU rating such as this Rheem unit for $900

If I were in your situation that's exactly what I would do.

Why on earth are you even replacing it? I know people with 30 year old tankless units that are still going strong. Yours should still work fine.

^^^ that's a fair question and one that I thought of as well. What I can see on the interwebs is that particular model was a problem child. Repairing the existing does solve a lot of problems if you can do it.

It’s already failing and we did the flush maintenance - a little bit better, but still problematic. I’m doing amother round of maintenance fix, but given our neighbors are already seeing theirs fail completely - we were all constructed around the same time - I doubt mine would last longer. I do think I will go with Jake’s proposal when it fails completely. Quote for that was $3400, device included with safety valve etc installed. I feel that is more aligned with my expectations. Thank you all!!

First of all, you’ve received some excellent advice and I’m not pretending for one second to be remotely as knowledgeable on the subject as people like Jake, but since the possibility exists of potentially doing additional work in order to satisfy current IRC or California earthquake building code or plumbing code or whatever authority has jurisdiction over your situation (I realize I’m taking liberties with these terms), does the location of your unit meet the minimum clearance requirements vis-à-vis ease of serviceability? From your photo and your description, it might not. (I know that the air handler for a heat pump I had installed during an attic conversion/remodel circa 2000 sure doesn’t!)

I don’t know off the top of my head what’s applicable in your case, but it’s something to take into consideration and, if found to be inadequate, might as well be taken care of at the same time as the rest of the mods.

Oh, and fwiw, I have two Rheem tankless systems (NG, outside install) that have provided trouble-free service for many years, now. Of course, now that I’ve said that, they’ll both fail within a week... :/